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Sections:

  • Introduction
  • I. Overview of Sodium Reduction
  • II. Science of Salt Reduction
    • 2.1 Dietary Guidance on Sodium and Potassium Intake
    • 2.2 Effect of Sodium on Blood Pressure
    • 2.3 Effect of Sodium on Health Outcomes
    • 2.4 Sodium and Potassium
    • 2.5 Modeling Impact and Cost-effectiveness of Sodium Reduction
    • 2.6 Taste, Sensory, Acceptability of Reduced Sodium Diet
    • 2.7 Sodium and Iodine
  • III. Surveillance
    • 3.1 Measuring Dietary Sodium Intake
    • 3.2. Population Sodium Intake
    • 3.3 Dietary Sources of Sodium
  • IV. Interventions
    • 4.1 Overall Summary of Interventions
    • 4.2 Industry Reformulation
    • 4.3 Front of Pack Labeling
    • 4.4 Knowledge and Behavior Change
    • 4.5 Changing the Environment
    • 4.5.1 Restaurants
    • 4.5.2 Healthy Public Food Procurement
    • 4.6 Salt Substitutes
    • 4.7 Taxation on High Sodium Foods
  • Appendix I: Sodium Conversion Values

Sodium Reduction

An Annotated Bibliography February 2021

Introduction

This bibliography is intended as a resource to support the design and implementation of national sodium reduction programs, and is useful for policy development, surveillance of population sodium sources and intake, and implementation of sodium reduction efforts. The aim is to provide a brief overview of the scientific basis of key aspects of sodium reduction strategies. This list is not representative of all aspects of sodium reduction and is largely drawn from the scientific literature published in English.

The bibliography is organized into four sections: first, a general overview of the consequences of sodium consumption and strategies for reduction; next, a review of the science behind salt reduction; third, surveillance strategies for measuring sources of sodium and population intake of sodium; and finally, a review of the various strategies recommended for large scale population sodium reduction.

I. Overview of Sodium Reduction

He FJ, MacGregor GA. A comprehensive review on salt and health and current experience of worldwide salt reduction programmes. Journal of Human Hypertension. 2009 Jun;23(6):363

Salt consumption is likely the major factor for increasing population blood pressure. Multiple studies show that populations with successful reductions in salt consumption also reduced blood pressure as well as other adverse health outcomes, particularly cardiovascular disease. Despite this strong evidence, many countries have not yet developed a salt reduction plan; however, a few countries such as Finland, Japan, and the UK have successfully implemented large-scale salt reduction programs through strategies such as industry engagement for product reformulation and labeling or through public health education.

Frieden TR. Sodium reduction—saving lives by putting choice into consumers’ hands. JAMA. 2016 Aug 9;316(6):579-80.

In the United States, high blood pressure is the leading cause of death from heart disease and stroke, and 90% of the population consumes too much sodium. Clear evidence from rigorous studies shows the benefit of sodium reduction on reducing blood pressure. Even small reductions in sodium intake can have great effects on hypertension prevalence, and likely on mortality from cardiovascular disease as well. “Over a decade, (a reduction of 1200 mg/d) could prevent up to an estimated 500000 deaths and may save an estimated $100 billion in health care costs.” Sodium reduction is unlikely to harm any segment of the population. This article advocates for the immediate implementation of the proposed US guidelines that would set voluntary sodium targets for industry.

Afshin A, Sur PJ, Fay KA, et al. Health effects of dietary risks in 195 countries, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. The Lancet. 2019 May 11;393(10184):1958-72.

The 2017 Global Burden of Disease study estimated that global consumption of sodium was 6g per day. High intake of sodium caused approximately 3 million deaths and 70 million disability-adjusted life-years (DALYs) in 2017. High intake of sodium was the leading dietary risk factor for mortality among men and was the leading risk for deaths and DALYs among older adults (≥70 years). It was also found to be the leading dietary risk factor for deaths and DALYs in east Asia and high-income Asia Pacific regions. Countries ranking high-middle and middle on the Socio-Demographic Index (SDI) were at the greatest risk of deaths and DALYs from high intake of sodium. For all countries except those at low SDI, sodium intake was one of the four leading dietary risks.

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II. Science of Salt Reduction

Overwyk KJ, Quader ZS, Maalouf J, et al. Dietary Sodium Intake and Health Indicators: A Systematic Review of Published Literature between January 2015 and December 2019. Adv Nutr. 2020;11(5):1174-1200. doi:10.1093/advances/nmaa049

This systematic review evaluates recent literature on the association between salt intake and health outcomes. Most studies published since 2015 do not address the research gaps or meet the recommendations for research methods outlined in the 2013 Institute of Medicine report on the scientific evidence on sodium and health outcomes. Reasons for this could include: a lack of knowledge about the recommendations, resources necessary, or time for implementation and reporting. Most of the published evidence on sodium and CVD risk between 2015 and 2019 was observational (a high number were cross-sectional) rather than interventional, thus subject to potential bias from error in assessment of sodium intake and confounding. Observational studies with clinical end points (CVD, mortality, etc.) had mixed results (positive, null, and negative). Further research is required, particularly RCTs examining the effects of sodium on CVD outcomes among the general population and for specific populations that are at higher risk, including chronic heart failure patients.

2.1 Dietary Guidance on Sodium and Potassium Intake

Added February 2021 WHO. Guideline: Sodium intake for adults and children. Geneva, World Health Organization (WHO), 2012. Available at: https://www.who.int/publications/i/item/9789241504836

WHO recommends that adults consume less than 2,000 mg of sodium, or 5 grams of salt per day. WHO also recommends a reduction in sodium intake to control blood pressure in children. For children, the recommended maximum for adults should be adjusted downward based on energy requirements of children relative to those in adults. A diet high in sodium increases the risk of raised blood pressure and increases the risk of heart disease and stroke. Reducing sodium intake significantly reduces blood pressure in both children and adults and has no adverse effects on blood lipids or renal function.

Added February 2021 WHO. Guideline: Potassium intake for adults and children. Geneva, World Health Organization (WHO), 2012. Available at: https://www.who.int/publications/i/item/9789241504829

WHO recommends that adults consume at least 3150 mg of potassium per day to reduce systolic and diabolic blood pressure and risk of cardiovascular disease in adults. An increase in potassium intake from food is also suggested for control of blood pressure in children. Evidence suggests that higher potassium intake has no adverse effect on blood lipids or renal function in adults but can decrease risk of cardiovascular disease, have beneficial effects on bone mineral density, and mitigate the negative effect of high sodium consumption. An uptake in potassium consumption can be achieved through the increased consumption of food high in potassium such as fresh fruit, vegetables, and beans.

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2.2 Effect of Sodium on Blood Pressure

Sacks FM, Svetkey LP, Vollmer WM, et al. Effects on blood pressure of reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH) diet. NEJM. 2001 Jan 4;344(1):3-10.

The DASH sodium study randomized participants to be fed three different sodium levels (3,400, 2,300 and 1,150 mg/day) of either the DASH diet (diet rich in fruits, vegetables, and low-fat dairy products, including whole grains, poultry, fish, and nuts) or a typical diet for 30 days at each sodium level. Among participants on a normal diet, those randomized to intermediate and low sodium levels saw a significant reduction in systolic BP of 2.1 mmHg and 6.7mmHg, respectively. Participants randomized to the DASH diet had even greater decreases in blood pressure at the low sodium levels. Compared to the typical diet group with high intake, they achieved systolic BP decreases of 7.1mm Hg (without hypertension) and 11.5 mm Hg (with hypertension). Both diets showed a progressive effect, with greater decreases in BP with further reductions in sodium intake.

Intersalt Cooperative Research Group. Intersalt: An International Study of Electrolyte Excretion and Blood Pressure. Results for 24-hour urinary sodium and potassium excretion. Intersalt Cooperative Research Group. BMJ. 1988;297:319-28.

Across 52 centers from 32 countries, median urinary sodium excretion values ranged from 4.6 mg/24 h to 5,568.3 mg/24 h. In the four study sites with very low sodium excretion, blood pressure was also found to be low, and there was no significant age-related rise in blood pressure. There was a linear relationship between the median 24-hour urinary sodium excretion and the slope of systolic and diastolic BP with age. After adjustment for body mass index and alcohol intake, all sites demonstrated this same relationship.

He FJ, Li J, MacGregor GA. Effect of longer term modest salt reduction on blood pressure: Cochrane systematic review and meta-analysis of randomised trials. BMJ. 2013 Apr 4;346:f1325.

“A 100 mmol reduction in 24-hour urinary sodium (~6 g/day salt) was associated with a fall in systolic blood pressure of 5.8 mm Hg (2.5 to 9.2, P=0.001) after adjustment for age, ethnic group, and blood pressure status”. Additionally, data from both of the two trials that compare multiple salt intake levels over time suggest a dose-response relationship with salt intake and BP, with larger salt reductions resulting in greater BP decreases. Reducing salt intake from the average of the analyzed trials (9.4 g/day) to 5-6 g/day would have significant impacts on lowering blood pressure, but reductions to 3 g/day would provide even greater benefits.

Geleijnse JM, Hofman A, Witteman JC, et al. Long-term effects of neonatal sodium restriction on blood pressure. Hypertension. 1997 Apr;29(4):913-7.

Using participants from a 1980 Dutch study that showed that “sodium intake was positive related to BP during the first 6 months of life”, this current study demonstrated that sodium intake during infancy may be associated with blood pressure later in life. Fifteen years after the 1980 study, 35% (167) of the original participants were selected for follow up. Compared to the control group (normal sodium intake), the low sodium intake group had 3.6 mm Hg lower systolic blood pressure (−6.6 to −0.5, p=.02) after controlling for confounding factors. Significant differences were not reported between groups for urinary sodium excretion.

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2.3 Effect of Sodium on Health Outcomes

Cook NR, Cutler JA, Obarzanek E, et al. Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP). BMJ. 2007;334(7599), 885.

One of the few trials assessing the impact of sodium intake on CVD, this study used long-term follow-up data from 3,126 prehypertensive adult participants of the trials of hypertension prevention (TOHP) to determine effects on cardiovascular disease outcomes. Participants were randomized to a control group or a sodium reduction intervention group lasting 18 months (TOHP I) or 36-48 months (TOHP II). The intervention groups showed a 30% reduction in cardiovascular disease and a 20% reduction in mortality compared to the control groups.

Aburto NJ, Ziolkovska A, Hooper L, et al. Effect of lower sodium intake on health: systematic review and meta-analyses. BMJ. 2013 Apr 4;346:f1326.

High-quality evidence from 36 randomized controlled trials shows that sodium reduction results in significant decreases in systolic (-3.39 mm Hg) and diastolic (-1.54 mm Hg) blood pressure in adults (reductions were greater among those with hypertension). Significant reductions were also found among children. Limited evidence from cohort studies showed that increased sodium intake had an increased risk of fatal coronary heart disease events (RR 1.32, 95% CI: 1.13 to 1.53), stroke (RR 1.24, 95% CI: 1.08 to 1.43), and stroke mortality (RR 1.63, 95% CI: 1.27 to 2.10).

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2.3.1 Conflicting Science

Webster J, Waqanivalu T, Arcand J, et al. Understanding the science that supports population‐wide salt reduction programs. Journal of Clinical Hypertension 2017 Jun;19(6):569-76.

Despite some limitations in available data, expert scientific groups overseen by governmental or nongovernmental health and scientific organizations agree on the need to reduce population salt intake. Salt reduction could result in millions of lives saved annually, especially cardiovascular deaths caused by hypertension. Although few randomized controlled trials (RCT) have been conducted to directly examine the effects of salt reduction on cardiovascular disease (CVD) due to feasibility and ethical concerns, pooling CVD data from RCTs with long-term follow up “have demonstrated a reduction in cardiovascular events with reduced dietary sodium.” A limited number of studies have concluded that low levels of sodium intake are associated with increased mortality; however, the methodologies of these studies are flawed. Strong evidence from higher-quality studies shows that CVD is reduced with lower intakes of dietary sodium. “The recent publication of a few paradoxical studies of questionable scientific merit should not delay implementation of salt reduction initiatives worldwide.”

Mente A, O'Donnell M, Rangarajan S, et al. Associations of urinary sodium excretion with cardiovascular events in individuals with and without hypertension: a pooled analysis of data from four studies. The Lancet. 2016 Jul 30;388(10043):465-75.

A pooled analysis from four prospective studies, including both healthy adults and adults with high risk of diabetes, vascular disease, or hypertension, found a U-shaped association between sodium excretion and cardiovascular events and mortality for individuals with hypertension. High sodium excretion (>7g/day) and low sodium excretion (<3g/day) were both associated with increased risk of cardiovascular disease events or all-cause mortality compared to those with sodium excretion of 4-5 g/day. For those without hypertension, only low sodium excretion (<3 g/day) was associated with a significantly increased risk. 24-hour sodium excretion was estimated based on spot urines.

He FJ, Campbell NR, Ma Y, et al. Errors in estimating usual sodium intake by the Kawasaki formula alter its relationship with mortality: implications for public health. IJE. 2018 Jun 22.

Use of the Kawasaki formula to estimate usual sodium intake can artificially introduce a J-shape curve. Sodium intake from 2,974 pre-hypertensive participants of the Trials of Hypertension Prevention (TOHP) study was assessed using four methods and compared to mortality. When using the gold standard method to measure sodium intake (multiple seven 24-h urinary sodium measurements), a linear relationship with mortality was found. Estimating usual intake by applying the Kawasaki formula (frequently applied to spot urines to estimate usual intake) to the sodium concentration from 3-7 collections, sodium at lower levels was over-estimated and sodium at higher levels was under-estimated. Further, using this method rather than the gold standard method, investigators observed an artifactual J-shaped relationship between sodium intake and mortality.

Olde Engberink RH, van den Hoek TC, van Noordenne ND, et al. Use of a single baseline versus multiyear 24-hour urine collection for estimation of long-term sodium intake and associated cardiovascular and renal risk. Circulation. 2017 Sep 5;136(10):917-26.

Using a single baseline 24-hour urine measurement rather than multiple measurements to estimate usual sodium intake can introduce an artifactual J-shaped relationship between sodium intake and CVD. Single baseline 24-hour sodium measurements as well as (multiple) follow-up 24-hour urine samples provide similar estimates of sodium intake on a population level; however, when used to estimate individual sodium intake, the two methods differ. When using a single baseline measurement, there was no significant association between high sodium intake and increased cardiovascular events/mortality and the curve appeared j-shaped. When using average measurements over 1 to 5 years, there was a significant, linear association.

Cogswell ME, Mugavero K, Bowman BA, Frieden TR. Dietary sodium and cardiovascular disease risk—measurement matters. NEJM. 2016 Aug 11;375(6):580.

This article explores whether low sodium intake causes cardiovascular disease (CVD) by applying Hill’s criteria for determining whether an observed association is causal: strength, consistency, specificity, temporality, biologic gradient, plausibility, coherence, experiment, and analogy. Ultimately, a causal association was not identified. Evidence for low sodium intake causing CVD are based on cohort studies which have known weaknesses such as residual confounding. They commonly use flawed sodium intake measurement methods, such as using spot urine samples, using single measurements rather than multiple 24-hour urine samples, and having a short follow-up period between salt reduction intervention and adverse outcomes. Further, they are contradicted by real-world population sodium reduction examples in the United Kingdom, Finland, and Japan as well as other scientific studies showing a progressive dose-response decrease in blood pressure down to as low as 1200 to 1500 mg per day and from the analysis of long-term follow up trial data showing sodium reduction resulting in decreased CVD events. Finally, in terms of biological plausibility, there is no evidence that reduced sodium intake has any long-term effect on other CVD risks such increased levels of cholesterol, triglycerides, renin, aldosterone, and catecholamine. The authors highlight that “invalid measurement of sodium intake and other methodologic limitations can lead to erroneous conclusions and delay effective public health action to reduce blood pressure and save lives”.

Cobb LK, Anderson CA, Elliott P, et al. Methodological issues in cohort studies that relate sodium intake to cardiovascular disease outcomes: a science advisory from the American Heart Association. Circulation. 2014 Mar 11;129(10):1173-86.

“Methodological issues may account for the inconsistent findings in currently available observational studies.” In a review of the quality of 26 cohort studies relating sodium intake to CVD, all but one study (Trials of Hypertension Prevention (TOHP)) had methodological issues that could potentially alter the direction of association (systematic error=22; reverse causality=16). Studies that reported an inverse or J-shaped were slightly most likely to contain an error with a potential to alter the direction of the association compared to studies with a positive association. The TOHP study, which did not find a J- or U-shape relationship utilized a more rigorous protocol including 3 to 7 24-hour urine samples and excluded participants with incomplete collections. Errors with the potential to lead to a false null result, such as random error in estimating sodium intake or having insufficient power, were present in 23 studies. Overall, studies had an average of 3-4 methodological problems, and study was quality was often difficult to assess due to insufficient information provided.

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2.3.2 Country Examples

Karppanen H, Mervaala E. Sodium intake and hypertension. Progress in Cardiovascular Diseases. 2006 Sep 1;49(2):59-75.

This article summarizes the scientific evidence relating high population salt intake with high prevalence of hypertension, using Finland as a case study. As average salt intake decreased by one third over 25-30 years in Finland, there was a simultaneous decrease of more than 10mm Hg in average population blood pressure (systolic and diastolic), a 75% to 80% decrease in both stroke and coronary heart disease mortality among those less than 65, and a 5- to 6-year increase in life expectancy. The article also describes salt-labeling legislation, such as the “high salt content” warning labels. This legislation encouraged product reformulation, resulting in reduced average salt content in the most important food categories. A sodium-reduced, potassium-, and magnesium-enriched salt alternative was also available and promoted. Methods for successful population level salt reduction are summarized.

He FJ, Pombo-Rodrigues S, MacGregor GA. Salt reduction in England from 2003 to 2011: its relationship to blood pressure, stroke and ischaemic heart disease mortality. BMJ Open. 2014 Apr 1;4(4):e004549.

A nationwide salt reduction program was introduced in the UK in 2003, and by 2011, a 15% reduction in population salt intake was observed. During this same period, a significant decrease in BP of 2.7 /1.1 mm Hg (p<0.001 for systolic and diastolic BP) was observed after adjusting for major factors known to be associated with BP. Decreased BP appears to be at least partially attributable to population salt reduction.

Mueller NT, Noya-Alarcon O, Contreras M, et al. Association of age with blood pressure across the lifespan in isolated yanomami and yekwana villages. JAMA Cardiology. 2018 Dec 1;3(12):1247-9.

This study among the Venezuelan Yanomami community (hunter-gatherer-gardeners with very low salt exposure) and the nearby Yekwana community (who have intermittent exposure to processed foods and salt) found that only the Yekwana experience an age-related rise in blood pressure. While both communities start out with similar blood pressures in early childhood, between-group differences in blood pressure increase with age rising to a 15.9 mm Hg difference by age 50 (the age-SBP slope was significantly steeper for Yekwana individuals). Overall, the Yanomami had significantly lower systolic and diastolic blood pressure than the Yekwana (SBP: 95.4 mmHg vs. 104.0 mmHg, P<0.001; DBP: 62.9 mm Hg vs. 66.1 mmHg; P = 0.03).

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2.4 Sodium and Potassium

Perez V, Chang ET. Sodium-to-potassium ratio and blood pressure, hypertension, and related factors. Advances in Nutrition. Advances in Nutrition. 2014 Nov 3;5(6):712-41.

Both reduced sodium intake and increased potassium intake have been reported to reduce blood pressure. This systematic review concluded that “the sodium-to-potassium ratio (Na-K ratio) is more strongly associated with blood pressure outcomes than either sodium or potassium alone in hypertensive populations”.

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2.5 Modeling Impact and Cost-effectiveness of Sodium Reduction

World Health Organization. Saving lives, spending less: a strategic response to noncommunicable diseases. World Health Organization; 2018.

Reducing unhealthy diets through reducing salt intake is considered a “Best Buy intervention” by the WHO. Recommended interventions to reduce salt intake include reformulation of food products, establishing a supportive environment in public institutions by providing low-salt options, education through behavior change communication and mass-media campaigns, and front-of-pack labelling. Investment in salt reduction activities offers the highest return among all Best Buy interventions, an estimated US$12.82 return on every US$1 invested.

Kontis V, Mathers CD, Rehm J, et al. Contribution of six risk factors to achieving the 25× 25 non-communicable disease mortality reduction target: a modelling study. The Lancet. 2014 Aug 2;384(9941):427-37.

Following the 2013 World Health Assembly, global commitments were made to reach a 25% relative reduction in premature mortality from non-communicable diseases (NCDs) by 2025. This study estimates that achieving the targets for six risk factors, including a 30% reduction in salt intake (others include tobacco and alcohol use, obesity, and raised blood pressure and glucose), would result in a decreased probability (-22% in men, -19% in women) of dying from any of the four major NCDs (cardiovascular diseases, chronic respiratory diseases, cancers, and diabetes).

Webb M, Fahimi S, Singh GM, et al. Cost effectiveness of a government supported policy strategy to decrease sodium intake: global analysis across 183 nations. BMJ. 2017 Jan 10;356:i6699.

In a global modeling study across 183 countries, the cost effectiveness of a 10-year government “soft regulation” policy consisting of combined targeted industry agreements and public education to reduce population sodium consumption by 10% was approximately I$204 per DALY saved with a population weighted mean cost of I$1.13 per capita. Nearly 5.8 million DALYs/year related to CVD would be averted. Cost effectiveness estimates widely ranged by country; however, in all but one country the interventions were cost effective as per the WHO benchmark (<3×GDP per capita).

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2.5.1 Country examples

Zhang J, Guo X, Lu Z, et al. Cardiovascular Diseases Deaths Attributable to High Sodium Intake in Shandong Province, China. JAHA. 2019 Jan 8;8(1):e010737.

Using 24-hour urinary sodium data from the 2011 SMASH study, authors estimated the annual number of CVD-related deaths in Shandong province attributable to high sodium intake and modelled the number of lives potentially saved through a 30% reduction in sodium intake. High sodium intake (>2000mg/day) was estimated to account for an estimated 16,000 CVD-related deaths in 2011 among those aged 25-69 (or nearly 20% of total CVD deaths) in Shandong. With a 30% reduction in sodium intake, Shandong province could potentially avert 8,800 sodium attributed CVD deaths, and with the SMASH sodium reduction goal of 4g/day, 6,700 sodium attributed deaths could be averted.

Rubinstein A, Martí SG, Souto A, et al. Generalized cost-effectiveness analysis of a package of interventions to reduce cardiovascular disease in Buenos Aires, Argentina. Cost Effectiveness and Resource Allocation. 2009 May 6;7(1):1.

A cost-effectiveness comparison of six individual and two population-based interventions to decrease CVD in Argentina found that population-based interventions were most cost effective, specifically, reducing salt in bread (ARS $151/DALY averted) and public health education through mass media (including promotion of a low-salt diet) (ARS $547/DALY averted).

Watkins DA, Olson ZD, Verguet S, et al. Cardiovascular disease and impoverishment averted due to a salt reduction policy in South Africa: an extended cost-effectiveness analysis. Health Policy and Planning. 2015 Apr 3;31(1):75-82.

Authors conducted a cost-effectiveness analysis to assess the South African Government policy to lower population salt intake to 5g per person/day by regulating salt in processed foods and conducting media campaigns. The policy would avert approximately 5,600 deaths and 23,000 cases of CVD yearly (11% of CVD deaths). It would also save US$ 4.06 million in household out-of-pocket expenditures on CVD, save US$51.25 million in government healthcare subsidies, reduce catastrophic spending, and prevent nearly 2,000 cases of poverty annually. Reformulating food products could cause food prices to rise, but the increase would at worst only be slightly more than the out of pocket expenditures averted.

Mason H, Shoaibi A, Ghandour R, et al. A cost effectiveness analysis of salt reduction policies to reduce coronary heart disease in four Eastern Mediterranean countries. PloS One. 2014 Jan 7;9(1):e84445.

A study of the cost-effectiveness of three salt reduction policies (health promotion campaign, labelling, and mandatory reformulation of salt content in processed food) in Tunisia, Syria, Palestine, and Turkey found that compared to no policy, the number of life years gained increased in all countries with all policies (separately and in combination). The majority of policies were cost saving as well. Policies including all 3 interventions resulted in the highest estimated cost savings, ranging from $6 million in Palestine to $1.3 billion in Turkey. Life years gained (LYG) under the same scenario included 6,455 LYG in Tunisia; 31,674 LYG in Syria; 2,682 LYG in Palestine and 378,439 LYG in Turkey.

Added February 2021 Dehmer SP, Cogswell ME, Ritchey MD, et al. Health and budgetary impact of achieving 10-year US sodium reduction targets. American journal of preventive medicine. 2020 Aug 1;59(2):211-8.

This study uses microsimulation modeling to estimate the potential health effects and associated budgetary impacts of averted disease costs over a 10-year period if mean sodium consumption among US adults is reduced to 2,300 mg/day. A 10-year graduated reduction in dietary sodium is projected to reduce the number of Americans with SBP > 140 mmHg by 6.9 million (22% reduction) and the number of Americans with SBP between 120 - 139 mmHg by 8.1 million (13% reduction). The reductions in sodium consumption are estimated to prevent 895,200 CVD events and 252,500 CVD-related deaths. The potential health benefits correspond with an estimated reduction in medical costs from averted disease by $36.9 billion across all payers in 10 years and increased productivity from reduced disease burden and premature mortality would account for an additional $18 billion in gains.

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2.6 Taste, Sensory, Acceptability of Reduced Sodium Diet

Bobowski N. Shifting human salty taste preference: potential opportunities and challenges in reducing dietary salt intake of Americans. Chemosensory Perception. 2015 Sep 1;8(3):112-6.

Dietary salt preference largely stems from one’s individual salt intake habits. Those who consume high sodium levels prefer the taste of high salt. This review paper highlights findings such as the impact of early exposure to salty foods in determining salt preference later in life, the ability for salt preference to change over time after limiting exposure, and the tendency not to overcompensate for low-sodium foods by adding salt at the table. Gaps in the research are also discussed, such as whether children’s salt preference can be shifted and why humans desire and consume salt in the absence of biological need.

Beauchamp GK, Bertino M, Engelman K. Failure to compensate decreased dietary sodium with increased table salt usage. JAMA. 1987;258(22):3275-8.

When sodium was reduced by nearly 50% in foods served to study participants, participants only added 20% back with a salt shaker at the table. Throughout the study, participants did not report any changes in taste perception.

Jaenke R, Barzi F, McMahon E, et al. Consumer acceptance of reformulated food products: A systematic review and meta-analysis of salt-reduced foods. Critical Reviews in Food Science and Nutrition. 2017 Nov 2;57(16):3357-72.

“[S]alt can be reduced in breads and processed meats by up to 37% and 67%, respectively, without a decrease in consumer acceptability.” For cheese products, meta-analysis showed decreasing levels of acceptance with increasing levels of salt reduction. Acceptance was lower in studies with salt reduction above 60%. Results varied for other products. Acceptability of products using low-sodium salts or flavor compensation were also studied. Replacing up to 50% of salt with potassium chloride in meat products or up to 30% in cheese was not found to impact acceptability.

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2.7 Sodium and Iodine

Because many populations primarily consume iodine through salt fortification, there is concern that reduction of salt intake will lead to inadequate consumption of iodine. Iodine fortification has been a major and successful public health initiative over the past 2-3 decades. Thus, it is important that progress in this area is not hindered but complemented by salt reduction strategies.

Campbell NR, Dary O, Cappuccio FP, et al. Need for coordinated programs to improve global health by optimizing salt and iodine intake. Revista Panamericana de Salud Pública. 2012;32:281-6.

Iodine fortification and salt reduction programs should be integrated in order to optimize intake of both nutrients. Integrated surveillance of both salt and iodine intake will be more efficient and effective than uncoordinated efforts. Public messaging to both use fortified salt and to reduce salt consumption should be coordinated and not conflicting or confusing. International agencies, national governments, health professionals, and NGOs must take action to ensure programs are integrated and lessons and resources are shared and leveraged across countries.

Verkaik-Kloosterman J, van Veer P, Ocké MC. Reduction of salt: will iodine intake remain adequate in The Netherlands?. British Journal of Nutrition. 2010 Dec;104(11):1712-8.

This modeling study in a Dutch population found that salt reductions of 12, 25 or 50% in industrially processed foods decreased mean salt intake by 7, 15 and 30% compared with current intake, and mean iodine intake by 6, 12 or 25%. Iodine intake levels remained adequate at all salt reduction levels for most the population. Reducing both discretionary salt and salt in industrial foods by 50%, led to a slight increase (1-11%) in inadequate iodine intakes for age groups above 3 years. For children aged 1-3 years, all scenarios led to inadequate iodine levels, affecting between 10% (12% industrial reduction) to 35% of the population (50% reduction industrial + discretionary). However, if industry meets the target of using iodized salt in 50% of industrially processed foods, there would be “adequate iodine intakes for virtually the whole population, including young children” for all scenarios.

Charlton K, Ware LJ, Baumgartner J, Cockeran M, Schutte AE, Naidoo N, Kowal P. How will South Africa’s mandatory salt reduction policy affect its salt iodisation programme? A cross-sectional analysis from the WHO-SAGE Wave 2 Salt & Tobacco study. BMJ Open. 2018 Mar 1;8(3):e020404.

In this cohort study of older South Africans, salt intake (measured by 24-hour urine) was positively associated with 24-hour iodine excretion (p<0.001). Those in the lowest salt intake category (<5g/day) did not meet iodine requirements (95 μg/day). Salt reduction programs may need to be accompanied by further iodine fortification efforts, and intake of both nutrients should be monitored simultaneously.

He FJ, Ma Y, Feng X, Zhang W, et al. Effect of salt reduction on iodine status assessed by 24 hour urinary iodine excretion in children and their families in northern China: a substudy of a cluster randomised controlled trial. BMJ Open. 2016 Sep 1;6(9):e011168.

In an RCT, a ~3.5-month school-based educational salt reduction program in northern China led to a significant decrease in salt intake of 1.9 g/day in children and 2.9 g/day in adults. Although iodine intake also decreased (19.3% in children and 11.4% in adults), iodine intake remained adequate.

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III. Surveillance

3.1 Measuring Dietary Sodium Intake

3.1.1 Spot urine vs. 24-hour urine for population values

Spot urine samples are much easier to collect and require far fewer resources than the gold standard, 24-hour urine method. This section looks at evidence examining how spot urine samples perform compared to 24-hour urine in determining population sodium intake.

Brown IJ, Dyer AR, Chan Q, et al. INTERSALT Co-Operative Research Group. Estimating 24-hour urinary sodium excretion from casual urinary sodium concentrations in Western populations: the INTERSALT study. AJE. 2013 May 14;177(11):1180-92.

Spot urine concentrations and 24-hour urinary sodium excretion collected by the Intersalt study (1885-1987 in 32 North American and European countries) were compared to determine the utility of estimating 24-hour urinary sodium excretion using spot urine specimens. The correlation (Pearson r) between observed and estimated 24-hour sodium excretion was 0.50 for individual men and 0.51 for individual women, and .79 for men at the population-level and 0.71 for women at the population-level. Bias was minimal (-1.8 mmol men; 2.2 mmol women) at the population level. Using spot urine estimations, the percent of people with sodium intake above the recommended levels was slightly higher than with observed 24-hour sodium excretion. Spot urine specimens may be able to provide useful estimates of population but not individual sodium intake.

Huang L, Crino M, Wu JH, et al. Mean population salt intake estimated from 24-h urine samples and spot urine samples: a systematic review and meta-analysis. IJE. 2016 Jan 21;45(1):239-50.

This study (a review of 29 studies estimating daily salt intake based on both spot and 24-hour urine) provides evidence that spot urine samples can be used to provide estimates of mean population salt intake; however, because spot urine systematically overestimated lower levels of salt intake and underestimated higher levels compared to 24-hour urine, spot urine samples should not be used to detect changes in average population salt consumption over time. For estimating mean population salt intake as above or below a 5g/day threshold, spot urine had a sensitivity of 97% and specificity of 100% (assuming 24-hour urine to be gold standard).

For similar article, see:

Santos JA, Li KC, Huang L, Mclean R, Petersen K, Di Tanna GL, Webster J. Change in mean salt intake over time using 24-h urine versus overnight and spot urine samples: a systematic review and meta-analysis. Nutrition journal. 2020 Dec;19(1):1-2.

Petersen KS, Wu JH, Webster J, et al. Estimating mean change in population salt intake using spot urine samples. IJE. 2016 Oct 18;46(5):1542-50.

Paired spot urine samples (drawn from the same population at two time points and analyzed as paired data) may be more useful for detecting change over time in population salt intake than un-paired samples. Approximately 1,000 participants in Australia in 2011 and 2014 provided 24-hour and spot urine samples. Using 24-hour urines, a significant decrease of 0.48 g/day of salt intake was seen. Although estimates using spot urine samples were not significantly different than those from the 24-hour urine data, only the estimates using paired samples also detected a significant change in sodium intake. This did not vary based on estimation equation. However, when analyzed by geographical location, “spot urine samples did not consistently detect the change in salt intake shown by the 24-h urine collections,” regardless of whether they were paired. Though paired spot urine may be a useful alternative to 24-hour for detecting changes in mean population salt intake, more evidence is needed before the success of salt reduction interventions can be reliably monitored without 24-hour urine collections.

Campbell NR, He FJ, Tan M, et al. The International Consortium for Quality Research on Dietary Sodium/Salt (TRUE) position statement on the use of 24‐hour, spot, and short duration (< 24 hours) timed urine collections to assess dietary sodium intake. J Clin Hypertens. 2019;21(6):700-9.

Based on a review of multiple systematic reviews and analyses, the International Consortium for Quality Research on Dietary Sodium/Salt (TRUE) concludes that the recommended method for assessing population dietary sodium intake is to collect “single complete 24-hour urine samples, collected over a series of days from a representative population sample” and for individual level estimations, “at least 3 non-consecutive complete 24-hour urine collections collected over a series of days that reflect the usual short-term variations in dietary pattern.” Generally, spot urine samples systematically underestimate changes in dietary sodium intake at the population level. To understand the role of single spot or short duration timed urine collections in assessing population average sodium intake will require more research. Single spot or short duration timed urine collections are not recommended for individual sodium intake estimation.

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3.1.2 24-hour urine vs. 24-hour dietary recall

McLean RM, Farmer VL, Nettleton A, et al, TRUE Consortium (International Consortium for Quality Research on Dietary Sodium/Salt). 24-hour Diet recall and Diet records compared with 24‐hour urinary excretion to predict an individual’s sodium consumption: A Systematic Review. J Clin Hypertens. 2018;20(10):1360-76

Thirty studies assessing individual sodium consumption compare estimates from 24-hour dietary recall or diet records vs. gold standard 24-urine collections. Results showed a wide variation between the methods. Correlations coefficients comparing diet recall to 24-hour urine ranged from 0.16 to 0.72. Comparing food diaries to the gold standard, correlations ranged from 0.11 to 0.49. The two studies that reported results of Bland-Altman limits of agreement analyses both found 24-hour diet recall did not accurately estimate intakes from 24-hour urines. Diet records or dietary recall alone may be useful to determine intake of certain nutrients, food groups, or dietary patterns, but is prone to error when used to determine individual sodium consumption or the relationships between individual sodium intake and health outcomes. Studies that rely solely on dietary assessment as a measure of individual sodium intake “must be viewed carefully and skeptically”.

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3.2. Population Sodium Intake

Powles J, Fahimi S, Micha R, et al., Global Burden of Diseases Nutrition and Chronic Diseases Expert Group (NutriCoDE). Global, regional and national sodium intakes in 1990 and 2010: a systematic analysis of 24 h urinary sodium excretion and dietary surveys worldwide. BMJ Open. 2013 Dec 1;3(12):e003733.

Using 24-hour urine-based and diet-based surveys from 66 countries (61% high-income regions, 40% low- or mid-income regions), authors estimated a mean level of global sodium consumption of 3.95g per day (or 10.06g/day of salt) as of 2010 (regional mean levels ranged from 2.18 to 5.51g sodium per day), with 99.2% of adults worldwide exceeding recommended level of 2.0g/day and 88.3% exceeding the recommended level by more than 1.0g/day. Men had slightly higher intake than women (4.14g/day vs 3.7g/day). Variation by age was small. Highest intakes were found in Asia (East Asia: 4.8g/day, Asia Pacific (high income): 5.0g/day, and Central Asia 5.51g/day. Next highest were Eastern Europe (4.18g/day), Central Europe (3.92g/day), and the Middle East and North Africa (3.92g/day). Lowest intakes were found in Sub-Saharan Africa, Latin America and the Caribbean and Oceania, although data was limited in these areas. A statistically non-significant increase in sodium intake globally was found using 24-hour urine data between 1990 and 2010.

Batcagan-Abueg AP, Lee JJ, Chan P, et al. Salt intakes and salt reduction initiatives in Southeast Asia: a review. Asia Pacific Journal of Clinical Nutrition. 2013 Nov 1;22(4):683-97.

A review of sodium consumption studies (19 total) in Southeast Asia (Indonesia, Malaysia, Philippines, Singapore, Thailand, Vietnam) found that “insufficient evidence exists regarding salt intakes in Southeast Asia”. Three countries (Malaysia, Philippines, Singapore) had national nutrition survey data, while data from the remaining countries came from smaller sub-national studies, except Vietnam where sodium consumption estimates were not available. Evidence suggests that sodium intake exceeds the recommended 2g/day in most countries, and men generally have higher intakes than women. The majority of intakes were between 1.2g – 4.5g/day. Thailand, Singapore, and the Philippines generally reported the highest intakes. Only two countries had data on children: Indonesian schoolchildren exceeded recommended limits (range of 2.12 – 3.58g/day) and two studies among Thai pre-school children showed inconsistent findings (range of 0.54-1.45g/day). Studies showed a large contribution of sodium comes from added salt and condiments/sauces. The most common sodium reduction interventions identified were consumer-focused, including dietary guidelines, promotion of diet/lifestyle changes, and public awareness campaigns. Fewer focused on food production or the environment.

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3.3 Dietary Sources of Sodium

L’Abbé M, Legetic B, Legowski B, et al. A review of methods to determine the main sources of salt in the diet. WHO/PAHO Regional Expert Group for Cardiovascular Disease Prevention through Population‐wide Dietary Salt Reduction. 2010.

Knowing the main sources of dietary salt in a country is essential for the development of effective salt reduction interventions. To determine baseline data on the major contributors to salt intake, authors recommend determining the level of discretionary salt in the household by a combination of direct and indirect methods (e.g., qualitative surveys or interviews, household food disappearance studies, “subtraction” methods), determining food consumption patterns through established survey instruments (if they exist) or by 24-hour recalls or food frequency questionnaires, and identifying the proportional importance of discretionary sources versus commercially prepared foods. They emphasize the importance of directing resources toward maintaining national or international food composition databases, either from primary or secondary sources.

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Added February 2021 Bhat S, Marklund M, Henry ME, Appel LJ, Croft KD, Neal B, Wu JH. A systematic review of the sources of dietary salt around the world. Advances in Nutrition. 2020 May 1;11(3):677-86.

This review identifies the sources of dietary salt in all countries with available data. The average daily salt intake of adults in these studies ranged from 5.2 in Guatemala to 15.5 g/day in China. Brazil, China, Costa Rica, Guatemala, India, Japan, Mozambique, and Romania appear to obtain more than half of their daily salt during cooking or at the table (discretionary salt). Populations in Jordan, Portugal, South Korea, Taiwan, and Turkey appear to receive between 25 and 50% of their daily salt from discretionary sources. On the other hand, discretionary salt intake accounts for less than 25% of daily salt intake in Australia, Austria, Canada, Denmark, Finland, New Zealand, the United Kingdom, and the United States of America. While there were no obvious regional patterns in the food sources of dietary salt, bread and bakery products, cereal and grain products, meat products, and dairy products appeared to be the main global contributors to daily salt intake. The study additionally found a significant inverse correlation between a country's GDP per capita and the proportion of daily salt intake from discretionary sources.

3.3.1 Country Examples

Anderson CA, Appel LJ, Okuda N, et al. Dietary sources of sodium in China, Japan, the United Kingdom, and the United States, women and men aged 40 to 59 years: the INTERMAP study. JADA 2010 May 1;110(5):736-45.

Using data from the INTERMAP study, major dietary sources of sodium among 4,680 adults aged 40-59 in China, Japan, the United Kingdom, and the United States were identified and compared. Sources of sodium were assessed from four multi-pass, in-depth 24-hour dietary recalls completed by each participant. In Japan, major sources of sodium included soy sauce (20%), soups (16.4%), processed fish or seafood (15%), and salted (pickled) vegetables and fruits (9.8%). In China, the main source was salt added during home cooking and at the table (75.8%), with 50% higher discretionary salt use in the north of China. In the United Kingdom, processed foods contributed to 95% of the sodium intake, with processed breads, cereals, and grains (34.6%) and processed red meats, poultry, and eggs (20.4%) being the highest contributors. Similarly, the major sources of salt in the United States came from processed foods (underestimated at 71%) with processed breads, cereals, and grains (19.5%) and processed red meats, poultry, and eggs (12.0%) being the highest contributors, as well as 11.7% from seasonings, sauces, dressings, etc. and 8.2% from dairy products.

Elorriaga N, Gutierrez L, Romero IB, et al. Collecting Evidence to Inform Salt Reduction Policies in Argentina: Identifying Sources of Sodium Intake in Adults from a Population-Based Sample. Nutrients. 2017 Aug 31;9(9):964.

Prior to implementing new legislation limiting the sodium content in select processed foods in Argentina, a 34-item Food Frequency Questionnaire was administered to 2,217 adults to estimate sodium intake from select foods, use of available low-salt alternatives, and the frequency of discretionary salt use. Average salt intake from selected processed foods was 4.7g/day (higher among men and those with lower education). “Soups and other convenience foods” were found to be the highest source of sodium (36.1%), followed by “Bread, crackers and cookies” (24.9%), “Meat products” (18.7%), and “Cheeses” (15.0%). Categories of foods with regulated maximum limits accounted for 47.6% of the total sodium intake from processed foods. Discretionary salt use was high, with 83.2% reporting always or often using use salt at the table or during cooking.

Blanco-Metzler A, Moreira Claro R, et al. Baseline and Estimated Trends of Sodium Availability and Food Sources in the Costa Rican Population during 2004–2005 and 2012–2013. Nutrients. 2017 Sep 15;9(9):1020.

Between 2004-2005 and 2012-2013, there was a statistically significant increasing trend in the amount of sodium available for consumption (p < 0.0001) based on food and beverage acquisition records from the Costa Rica Household Budget Surveys. The availability of sodium per person per day increased from 3.9g to 4.6g. Table salt was the main source of dietary sodium (60.2%) in both 2004-2005 and 2012-2013, with participants using an estimated 2.4-2.8g/day. The next major source of sodium was processed foods (15.4% in 2004-2005, 14.2% in 2012-2013), followed by condiments (9.3% in 2004-2005, 13.2% in 2012-2013), and ready to eat meals (9.8% in 2004-2005, 7.2% in 2012-2013). Intake of processed foods and sodium-based condiments increased over the time period, while ready to eat meals and natural foods containing sodium decreased over time.

Johnson C, Santos JA, Sparks E, et al. Sources of Dietary Salt in North and South India Estimated from 24 Hour Dietary Recall. Nutrients. 2019 Feb;11(2):318.

In both North and South India, added (discretionary) salt was the main source of sodium in the diet (87.71% in South India and 83.45% in North India). Additional sources in the south included meat, poultry, and eggs (6.3%), dairy and dairy products (2.6%), and fish and seafood (1.6%); in the north, additional sources included dairy and dairy products (6.4%), bread and bakery products (3.3%), and fruits and vegetables (2.1%). No significant differences were found within regions for salt intake based on sex, age, or education level. In South India, urban areas consumed more salt from added salt than rural areas (90% vs. 86%); however, in North India, rural areas consumed more (86% vs. 81%). Data was collected based on two 24-hour dietary recalls from 1,283 participants selected from rural, urban, and slum areas in North and South India.

Added February 2021 Du S, Wang H, Zhang B, Popkin BM. Dietary potassium intake remains low and sodium intake remains high, and most sodium is derived from home food preparation for Chinese adults, 1991–2015 trends. The Journal of nutrition. 2020 May 1;150(5):1230-9.

This study assessed changes in sodium intake over time from the China Health and Nutrition Survey, an open cohort study conducted between 1991-2015. Detailed diet data was collected for 29,926 Chinese adults, using weighing methods at the household level in combination with three consecutive 24-hr recalls at the individual level. Sodium intake was 6.3g/d in 1991, decreasing to 4.1 g/d in 2015. Sources of sodium intake did not change significantly over time. The major source of sodium was salt added during cooking, which accounted for 67% of the total sodium intake in 2015. Sodium from processed foods increased slightly, from 5.0% in 1991 to 8.8% in 2015. The sodium/potassium ratio decreased from 4.1 in 1991 to 3.1 in 2015, 5 times higher than the WHO recommendation. Overall, sodium intake in China remains very high and further sodium reduction efforts need to be considered

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IV. Interventions

4.1 Overall Summary of Interventions

Added February 2021 Ide N, Ajenikoko A, Steele L, et al. Priority Actions to Advance Population Sodium Reduction. Nutrients. 2020 Sep;12(9):2543.

The article proposes a framework for prioritizing interventions that have the highest potential to reduce population sodium intake, evaluates existing interventions against the framework, and identifies and describes the recommended high-impact interventions. The framework provides three inclusion criteria to identify high impact strategies. The strategies should be 1) scalable and sustainable 2) have evidence of effectiveness or if there is no strategy proven effective for a particular source of sodium, be an innovative and promising approach and 3) have a large benefit. For evidence of effectiveness, the strategy must either be rigorously evaluated with demonstrated success in sodium reduction, provide suggestive evidence of effectiveness from lower quality evaluation or modeling studies or be rigorously evaluated strategies that do not specifically target sodium reduction but can be applied to sodium reduction. Seven strategies were found that met the three framework criteria and were organized by primary source of sodium (i.e., packaged food, sodium consumed at home, and sodium consumed from food prepared outside the home). For packaged food: front-of-pack labeling, packaged food reformulation targets, regulating marketing to children, and taxation on high sodium food. For sodium consumed at home: mass media campaigns and population uptake of low-sodium salt. For sodium consumed outside the home: food procurement policies for public institutions. Governments should concentrate on the highest-impact strategies and take a multi-component approach to addressing excess sodium consumption as no single strategy is enough to reach the WHO goal of 30% reduction in sodium intake by 2025.

Trieu K, Neal B, Hawkes C, et al. Salt reduction initiatives around the world–a systematic review of progress towards the global target. PloS One. 2015 Jul 22;10(7):e0130247.

Between 2010 and 2014, the number of countries with national salt reduction strategies more than doubled (to 75 countries) with another nine planned. Most are in high- or upper-middle income countries, with only 11 in lower-middle income countries and one in a low-income country. Most strategies incorporate multiple components, including industry reformulation (61 countries), setting sodium targets for one or more food categories (39), consumer education (71), front-of-pack labeling (31), interventions in public institution settings (54), and salt taxation (3). Consumer education was the most common approach in all regions except the Americas, where industry engagement was most common. 33 countries have taken some sort of legislative action on salt reduction (mandatory salt targets, taxation, front of pack labeling, or standards for salt as part of procurement policies in public institutions). As of 2014, 12 countries reported reductions in population salt intake, 19 reported reductions in salt levels in foods, and 7 reported improvements in consumer knowledge, attitudes or behaviors relating to salt.

Barberio AM, Sumar N, Trieu K, et al. Population-level interventions in government jurisdictions for dietary sodium reduction: A Cochrane Review. International Journal of Epidemiology. 2017 Feb 15;46(5):1551-405.

This Cochrane review assessed the impact of population-level sodium reduction interventions in 10 countries with adequate data for assessment. Five of these ten countries showed a mean decrease in salt intake from before to after intervention (China, Finland (Kuopio area), France, Ireland, UK), ranging from -1.15g/day in Finland to -0.35g/day in Ireland. Two initiatives resulted in a mean increase in salt intake (Canada, Switzerland). Of the seven multicomponent interventions that were structural in nature (targeting environments rather than directly targeting behavior change, e.g. reformulation or procurement policies), four showed a mean decrease in salt intake. The overall quality of evidence rating was “very low”. Only 10 of the 75 countries with sodium reduction initiatives originally identified provided sufficient data for quantitative analysis, which demonstrates the frequent lack of plans to monitor sodium reduction initiatives or a limited data infrastructure in general.

Hyseni L, Elliot-Green A, Lloyd-Williams F, et al. Systematic review of dietary salt reduction policies: Evidence for an effectiveness hierarchy? PloS One. 2017 May 18;12(5):e0177535.

This systematic review including 70 studies shows that comprehensive, multi-component strategies that use “upstream, structural” policy-based population approaches (e.g., mandatory reformulation) generally achieve the largest reductions in population-wide salt consumption. When assessed separately, “mandatory reformulation alone could achieve a reduction of approximately 1.45g/day (three separate studies), followed by voluntary reformulation (-0.8g/day), school interventions (-0.7g/day), short term dietary advice (-0.6g/day) and nutrition labelling (-0.4g/day), but each with a wide range”. Smaller reductions were seen for taxation, community-based counseling, health education media campaigns, and worksite interventions.

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4.1.1 Country/Regional Examples

Laatikainen T, Nissinen A, Kastarinen M, Jula A, Tuomilehto J. Blood pressure, sodium intake, and hypertension control: lessons from the North Karelia Project. Global Heart. 2016 Jun 1;11(2):191-9.

This article describes the North Karelia Project, an intensive hypertension prevention and control program started in 1972 in North Karelia, Finland. In the late 1970s, sodium reduction efforts were scaled up to address the extremely high intake of sodium in the population, which eventually resulted in decreased average salt intake as well as significant reductions in blood pressure between 1982 and 1997. Interventions included: 1) health education targeted to the whole population, 2) education of patients including nutrition counselling, 3) training of personnel on the association between salt intake and blood pressure and on food preparation, and 4) environmental changes including introduction of low-sodium salt, reducing salt content in school meals and at other institutions, and working with industry to reformulate products with less salt.

Added February 2021 Xu A, Ma J, Guo X, et al. Association of a province-wide intervention with salt intake and hypertension in Shandong Province, China, 2011-2016. JAMA internal medicine. 2020 Jun 1;180(6):877-86

The Shandong-Ministry of Health Action on Salt and Hypertension (SMASH) program was a government-led, population-based intervention to reduce salt intake and decrease the risk of hypertension among adults in Shandong province. The program consisted of a media campaign and distribution of scaled salt spoons, along with promotion of low-sodium products in markets and restaurants and public education activities targeting reduction of sodium at home and at school. The program led to a decrease in sodium intake in Shandong province of 24.8% from 2011 to 2016 (5,338 mg/day to 4,013 mg/day) as measured by 24-hour urine sodium excretion. In addition, potassium excretion increased by 15.1% (from 1,607 mg/day to 1,850 mg/day) and the sodium to potassium ratio decreased by 36.6% (6.9 to 4.3). The adjusted mean systolic BP decreased by 1.8 mm Hg from 131.8 in 2011 to 130 mm Hg in 2016 (p = 0.04). The adjusted mean diastolic BP decreased by 3.1 mm Hg from 83.9 mm Hg to 80.8 mm Hg (p < 0.001). Sodium reduction and hypertension knowledge, attitudes, and behaviors significantly improved, including knowledge of the salt intake recommendation by the Chinese Dietary Guidelines, attention paid to processed food labeling, and actions taken to reduce sodium in the diet. Findings of the study suggest that SMASH is the first large scale population-based intervention primarily relying on behavior change that showed such a large reduction in sodium intake, and therefore may have implications for sodium reduction and blood pressure control in other regions of China and worldwide.

Shao S, Hua Y, Yang Y, et al. Salt reduction in China: a state-of-the-art review. Risk Management and Healthcare Policy. 2017;10:17.

Most of the Chinese population far exceed recommended daily salt consumption, with levels ranging from 7.6g/day in Fujian and Guangdong provinces to 15.2g/day for adults in Beijing. Western China generally has a higher intake (12.5 g/day) than eastern China (8.6 g/day). Salt intake has declined since the 1990s. Most salt is reported to be from cooking at home. Interventions conducted in China to reduce salt consumption include: 1) Policies: required labeling of salt content, regulating low-sodium salt, 2) National initiatives: multisector health education campaigns, 3) Regional initiatives: salt restriction tools/spoons, promotion of low-sodium salt, subsidies for manufacturers of low salt products, product placement in supermarkets, and 4) Research on low-sodium salt. Authors recommend alignment of government, industry, academic, and consumer stakeholders through a Salt Reduction Task Force to spearhead, coordinate, and monitor nation-wide salt reduction efforts. Targeted messaging, setting salt targets for industry, food labeling, scaling up salt restriction tools and salt substitutes were also recommended.

Added February 2021 Park HK, Lee Y, Kang BW, Kwon KI, Kim JW, Kwon OS, Cobb LK, Campbell NR, Blakeman DE, Kim CI. Progress on sodium reduction in South Korea. BMJ global health. 2020 May 1;5(5):e002028

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South Korea’s sodium reduction program led to a 23.7% reduction in adult dietary sodium intake between 2012 and 2014. The program included five components: (1) a consumer awareness campaign designed to change food consumption behaviors; (2) increased availability of low-sodium foods at school and worksite meal services; (3) increased availability of low sodium meals in restaurants; (4) voluntary reformulation of processed foods to lower the sodium content; and (5) development of low-sodium recipes for food prepared at home. The reductions in sodium were accompanied by reductions in population blood pressure and hypertension prevalence. The reductions in salt in kimchi, one of the major sources of sodium in South Korea, was a big driver for the change. The engagement of the food industry in product reformulation also helped with the reduction of sodium intake. Lessons learned from South Korea, particularly its multi-component approach and focus on major contributors to sodium intake, could be applied to other countries, particularly those with similar food sources and consumption profiles.

Pillay A, Trieu K, Santos JA, et al. Assessment of a salt reduction intervention on adult population salt intake in Fiji. Nutrients. 2017 Dec 12;9(12):1350.

Fiji implemented a 20-month national salt reduction intervention between 2014-2015 including strategic health communication (through a health educator training program and a public awareness campaign); a hospital program (education and reducing salt in meals); and engagement of food manufacturers and food retailers to voluntarily lower the salt content of foods, use reduced salt products, and remove salt shakers from tables. To assess the impact, 24-h urine samples were taken before and after the 20-month intervention. Sodium intake decreased from 11.7g/day to 10.3g/day, which was not statistically significant (p=0.115).

Enkhtungalag B, Batjargal J, Chimedsuren O, et al. Developing a national salt reduction strategy for Mongolia. Cardiovascular Diagnosis and Therapy. 2015 Jun;5(3):229.

In 2010, Mongolia initiated action to develop a national salt reduction strategy. An inter-sectoral working group was established with government officials and industry representatives to raise awareness and invite collaborations. Baseline data on salt intake and sources were obtained, showing a mean salt intake of 11.06g/day and a high intake of salt from salty tea (30%), meals (23%), and other processed foods (47%). Pilot salt reduction initiatives were launched from 2011-2014, resulting in improved consumer awareness, reductions in salt intake among factory workers, and voluntary reductions among bakeries, the meat industry, and others. These activities were used to inform the national salt reduction strategy in 2014, which aims to “create a social, economic and legal environment to support the reduction of population salt intake by 30% by 2025”. Implementation of this strategy is planned for 2015-2025 and aims to 1) advance the legal environment for salt reduction; 2) improve partnerships, and 3) create an enabling environment to support consumers to make the right choices.

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4.2 Industry Reformulation

Webster J, Trieu K, Dunford E, Hawkes C. Target salt 2025: a global overview of national programs to encourage the food industry to reduce salt in foods. Nutrients. 2014 Aug 21;6(8):3274-87.

Fifty-nine countries have engaged the food industry to reduce salt in foods (another 12 plan to engage industry). 35 countries established voluntary salt targets, nine established mandatory targets, and 23 reported holding industry meetings. Most countries with mandatory targets had targets for bread only. Only two (South Africa and Argentina) had mandatory targets for a range of products. Of the countries engaging industry, 44 reported having established monitoring mechanisms for packaged food, with most using at least chemical analysis of food, and 17 countries documented reductions to salt levels in at least one product. Efforts to engage industry were largely found in the Americas, Europe, and the Western Pacific, with fewer in Africa, Eastern Mediterranean, or South East Asia.

Downs SM, Christoforou A, Snowdon W, et al.. Setting targets for salt levels in foods: A five-step approach for low-and middle-income countries. Food Policy. 2015 Aug 1;55:101-8.

“The aim of this paper is to propose a step-by-step approach to setting and implementing targets for salt levels in foods for LMICs, which can then be used for voluntary or mandatory policy interventions.” The five main steps are: 1) identifying the main sources of salt in the diet, 2) selecting foods for salt targets, 3) setting target levels in foods, 4) identifying strategies for engagement with stakeholders and 5) establishing mechanisms for monitoring. Multiple implementation strategies for each step exist, and a hierarchy of “the most to least desirable based on validity and methodological strength” is provided for each step. Salt targets can be used not only for directly regulating the sodium content in processed foods, but also to implement labeling, food procurement, and taxation policies.

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4.2.1 Country Examples

Curtis CJ, Clapp J, Niederman SA, Ng SW, Angell SY. US food industry progress during the National Salt Reduction Initiative: 2009–2014. AJPH. 2016 Oct;106(10):1815-9.

The National Salt Reduction Initiative (NSRI) is a U.S.-based coalition initiated in 2009 aimed at “reducing population sodium intake by 20%, through a reduction in sodium in US packaged and restaurant foods by 25% by 2014”. The NSRI set target levels in 61 packaged food categories for 2012 and 2014. “In 2009, when the targets were established, no categories met NSRI 2012 or 2014 targets. In 2014, 16 (26%) categories met 2012 targets and 2 (3%) met 2014 targets.” By 2014, 45% of food products had achieved the 2012 targets. From 2009 to 2014, the sales-weighted mean sodium density declined significantly by 6.8%, with reductions seen in 43% of food categories. No change was reported in restaurant food.

He FJ, Brinsden HC, MacGregor GA. Salt reduction in the United Kingdom: a successful experiment in public health. Journal of Human Hypertension. 2014 Jun;28(6):345.

“(T)he United Kingdom now has the lowest known salt intake of any developed country as measured by 24-h urinary sodium” (as of 2014). The nine key components of the salt reduction program in the United Kingdom, were: (1) setting up an action group; (2) determining salt intake and sources of salt; (3) setting a target for population salt intake and developing a salt reduction strategy; (4) setting progressively lower salt targets for industry with a clear time frame; (5) working with the industry to reformulate food with less salt; (6) engaging and recruiting of ministerial support; (7) clear nutritional labelling; (8) consumer awareness campaign; and (9) monitoring progress. The salt reduction program in the UK achieved a 15% reduction in average salt intake, from 9.5g/day in 2003 to 8.1g in 2011 (P<0.05). Product surveys show that the salt content in processed foods decreased during the program, including a 20% decrease in bread and 45% in ready meals. Between 2003-2007, the percentage of adults who add salt at the table decreased from 32.5% to 23.2%, and sales of table/cooking salt decreased by approximately 20%. The program was shown to be very cost-effective (£1.5 billion saved per year) and led to approximately 6,000 fewer deaths from cardiovascular disease per year by 2008.

Added February 2021 Laverty AA, Kypridemos C, Seferidi P, et al. Quantifying the impact of the Public Health Responsibility Deal on salt intake, cardiovascular disease and gastric cancer burdens: interrupted time series and microsimulation study. J Epidemiol Community Health. 2019 Sep 1;73(9):881-7.

The Public Health Responsibility Deal was a public-private partnership launched in England, which gave greater freedom to the food industry to set and monitor targets for salt content of food, eliminating the Food Standards Agency’s strong oversight and monitoring of industry during England’s multicomponent salt reduction strategy from 2003-2010. Between 2003 and 2010, mean salt intake decreased annually by 0.20 g/day for men and 0.12 g/day for women (p <0.001). However, between 2011 and 2014, after the Responsibility Deal was implemented, annual reductions in salt intake slowed significantly to 0.11 g/day for men and 0.07 g/d for women (p <0.001). The study estimated that this shift was responsible for 9,900 additional cases of CVD and 1500 additional cases of gastric cancer between 2011 and 2018. Public-private partnerships such as the Responsibility Deal which lack target setting, monitoring, and enforcement are unlikely to produce optimal health gains.

Arcand J, Blanco-Metzler A, Benavides Aguilar K, et al. Sodium Levels in Packaged Foods Sold in 14 Latin American and Caribbean Countries: A Food Label Analysis. Nutrients. 2019 Feb;11(2):369.

In 2015, the Salt Smart Consortium released a set of sodium reduction targets for 12 categories of packaged foods throughout Latin America and the Caribbean. Targets included a regional target (maximum) level and a more aggressive lower target level (used as the goal). Overall, 82% of packaged foods in the 14 countries surveyed met the regional target level, and 47% met the lower target level. In all countries, at least of 77% of products met at least the regional target. The proportion of foods meeting the sodium targets varied, both across countries and food categories. Food categories meeting the targets most frequently included uncooked noodles and pasta, flavored cookies and crackers, seasonings, mayonnaise, and cured and preserved meats (all above 91%). Categories with the lowest proportion meeting the targets include wet and dry soups, bouillon cubes/powders, breaded meat and poultry, and cakes.

Hofman KJ, Lee R. Intersectoral case study: Successful sodium regulation in South Africa. World Health Organization Regional Office for Africa. 2013.

In 2016, South Africa began to implement mandatory regulation of sodium used in processed foods for several industries. Sodium limits were set for foods with the highest sodium, particularly bread, which contributes about 25–40% of an average South African’s daily intake of sodium, as well as for butter and margarine, savory snacks, processed meats, and soup mixes. Limits are to be phased in over a three-year period, with the first deadline in June 2016 and stricter limits in June 2019. Methods for enforcement and testing sodium levels for compliance were included in the legislation. Challenges to the process of developing this legislation, include industry pressure, concerns related to enforcement, and concerns about an expected increase in bread prices due to the reformulation costs. Regulations were made possible by intersectoral collaboration among government, academia, and industry; strong government commitment to regulating sodium; a consultation process with nutrition and hypertension-related academics, representatives of the food industry, and non-governmental organizations; and adequate consideration given to understanding industry concerns and providing “an inclusive and respectful approach”.

Alhamad N, Almalt E, Alamir N, Subhakaran M. An overview of salt intake reduction efforts in the Gulf Cooperation Council countries. Cardiovascular Diagnosis and Therapy. 2015 Jun;5(3):172.

There has been variable progress in salt reduction efforts across countries in the Gulf Cooperation Council (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and United Arab Emirates). Intake remains high, with people in most countries consuming more than 12g/day. Efforts to reduce the salt content of bread, the major source of sodium, have been initiated in all countries. At the time of this study, only Qatar and Kuwait had made substantial progress, with a 10-20% salt reduction in bread. Challenges include “lack of political commitment, inexperience and shortage of qualified human resources”. Other regional efforts include surveillance (Kuwait, Oman, Bahrain), food labeling (Bahrain), engaging the private sector on health education (Kuwait), and reducing salt in other processed foods such as cheese and processed meats (Kuwait, Oman).

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4.3 Front of Pack Labeling

Added February 2021 Croker H, Packer J, Russell SJ, et al. Front of pack nutritional labelling schemes: a systematic review and meta‐analysis of recent evidence relating to objectively measured consumption and purchasing. Journal of Human Nutrition and Dietetics. 2020 Aug;33(4):518-37.

This systematic review assessed the impact of front-of-pack labelling for food and non-alcoholic drinks on purchasing and consumption of prepackaged foods. A meta-analysis of 14 studies including information on purchasing and consumption showed significant reductions in the content of sodium (-24.5mg per 100g) and sugar (-0.40g per 100g) in purchased products with a front-of-pack label compared to products with no label and non-significant reductions in energy and saturated fat content. In terms of particular types of labels, "high in" warning labels significantly reduced purchase content of energy, sugar, and sodium; multiple traffic light labels decreased sodium content with a trend towards reduction in the purchase content of saturated fat, and the health star rating scheme did not show significant findings. The findings suggest that front-of-pack labels, particularly interpretive models like "high in" warnings, improve the health of food purchases.

For similar articles, see:

Song J, Brown MK, Tan M, et al. Impact of color-coded and warning nutrition labelling schemes: A systematic review and network meta-analysis. PLoS medicine. 2021 Oct 5;18(10):e1003765.

Shangguan S, Afshin A, Shulkin M, et al. A Meta-Analysis of Food Labeling Effects on Consumer Diet Behaviors and Industry Practices. AJPM. 2018 Dec 17.

Roberto CA, Ng SW, Ganderats-Fuentes M, et al. The Influence of Front-of-Package Nutrition Lableing on Consumer Behavior and product Reformulation. Annu Rev Nutr. 2021. 41:22.1–22.22

Added February 2021 Vital Strategies and University of North Carolina at Chapel Hill. What’s in Our Food? A guide to introducing effective front-of-package nutrient labels. Trish Cotter, Lindsey Smith Taillie, Nandita Murukutla, Luyanda Majija, Alexey Kotov, Marissa Hall, Sandra Mullin, Barry Popkin. September 2020.

The guidance document provides advice for governments, researchers, civil society groups, and other stakeholders who are involved with the design and development of front-of-pack nutrient labels. These labels are a highly effective mean of communication with consumers at the point of decision-making and purchase. They help consumers identify unhealthy foods and make healthier choices, improve dietary intake, reduce diet-related NCDs, and can also stimulate healthier food production and product reformulation. The guide outlines strategies for research, communication, and development of front-of-pack labels. Governments seeking to implement front-of-pack labels should follow these steps: define the public health problem; determine scientific criteria for labels; review existing labels for other settings for use in the local context; engage civil society; form an expert advisory committee; build public support; test label designs and identify an effective label; develop graphic design guidelines for implementing labels; and evaluate policy impact.

For similar document, see:

World Cancer Research Fund International (2019). Building momentum: lessons on implementing a robust front-of-pack food label. Available at wcrf.org/buildingmomentum.

Added February 2021 Taillie LS, Hall MG, Popkin BM, et al. Experimental studies of front-of-package nutrient warning labels on sugar-sweetened beverages and ultra-processed foods: A scoping review. Nutrients. 2020 Feb;12(2):569.

This scoping review describes a conceptual model for how front-of-pack warning labels affect consumer behavior, examines which outcomes are currently measured in the literature, and reviews the existing evidence on front-of-pack warning labels from randomized control experiments. The conceptual model for how nutrient warnings change behaviors includes attention to the label; comprehension, cognitive elaboration, and message acceptance; eliciting a negative affect or perception of risk; behavioral intentions; and behavioral response. Based on the 22 studies reviewed in this article, it was found that compared to a no-label control, nutrient warnings were visible, easy to understand, and improved consumers' ability to identify unhealthy products. Other labeling systems were reported to provide more nutrition information and enabled participants to better rank products' healthfulness. Overall, actual behavioral outcomes were tested less frequently than outcomes such as attention, comprehension, and purchasing intentions. Of the studies that tested behavioral outcomes, nutrient warnings improved the healthfulness of food purchases. More research is required to better understand the pathway to behavioral outcomes, particularly in reducing purchases of unhealthy food and beverages.

Added February 2021 Jones A, Neal B, Reeve B, et al. Front-of-pack nutrition labelling to promote healthier diets: current practice and opportunities to strengthen regulation worldwide. BMJ global health. 2019 Dec 1;4(6):e001882.

The paper examined 31 existing front-of-pack nutrient labelling regulations along three domains, 1) the form of regulation used (regulatory form), 2) its substantive terms and conditions (regulatory substance), and 3) the application of good governance in its development, administration, and enforcement (regulatory governance), in order to identify best practices for designing successful front-of-pack labelling regulations. Best practices identified in each domain include: Regulatory form: When designing regulations, governments should consider mandatory legal frameworks to overcome suboptimal voluntary uptake. For front-of-pack labels to promote healthier diets, policymakers should select a label that consumers can easily understand and use. Regulatory substance: The terms and content of the regulation should include strategic and measurable objectives, require specifications to ensure the label is clearly visible on the package, include nutrients and/or food components that address the relevant diet-related risks, specify a valid set of nutrient profiling criteria, apply broadly across most packaged foods in the market, and frame front-of-pack legislation within a comprehensive set of policies to promote healthier diets. Regulatory governance: Governments should initiate front-of-pack labeling and be responsible for setting regulatory objectives, scope, and criteria. Furthermore, government, or an independent body with the authority to monitor and enforce, should administer the regulation. A framework for monitoring and evaluation should be set during development and should include effective means of enforcement.

Added February 2021 Campbell NR, Webster J, Blanco-Metzler A, et al. Packages of sodium (Salt) sold for consumption and salt dispensers should be required to have a front of package health warning label: A position statement of the World Hypertension League, national and international health and scientific organizations. Journal of clinical hypertension (Greenwich, Conn.). 2019 Nov 1;21(11):1623-5.

Several countries require labels on processed foods to indicate products high in salt. However, these labels are typically only applicable to multi-ingredient packaged foods, not to packages of salt where the only content is sodium chloride. This position statement requests governments to require health warnings on packages of salt sold for consumption and on salt dispensers in restaurants, such as saltshakers. The potential benefits of warning labels on packages of sodium chloride include increased awareness of the dangers of high sodium diets by those purchasing sodium and a reminder of the dangers by people seeing the containers at stores, food service establishments, or in the home. Additionally, stores that sell salt might display it less prominently, which could lead to a reduction in sodium consumption.

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4.3.1 Comparing Types of Labels

Becker MW, Bello NM, Sundar RP, et al. Front of pack labels enhance attention to nutrition information in novel and commercial brands. Food Policy. 2015 Oct 1;56:76-86.

Experiments tracking participants’ allocation of attention to various iterations of front of pack label (FOPL) designs and traditional Nutrition Facts Panel (NFP) designs found that participants were more likely to detect changes to the labels with FOPL designs than NFP, meaning that the FOPL designs “garner attention more readily” than NFPs. Changes were detected even faster when FOPL designs used colors; using facial icons (smiling/frowning faces) did not have an impact on the participants’ attention.

Arrúa A, Machín L, Curutchet MR, et al. Warnings as a directive front-of-pack nutrition labelling scheme: comparison with the Guideline Daily Amount and traffic-light systems. PHN. 2017 Sep;20(13):2308-17.

This comparison study of front-of-pack warning labels versus Guideline Daily Amounts (GDA) and traffic-light system labels found that warning labels were most effective at improving customers’ ability to identify unhealthful products. Warning labels required the least amount of time to correctly identify whether a product was high in sodium or other key nutrients compared to the traffic light system and GDA. An additional perceived healthfulness experiment showed that “products with high energy, saturated fat, sugar and/or sodium content that featured warnings on the label received significantly lower healthfulness scores than those featuring the GDA or the traffic-light system.” Both warning and traffic-light systems better allowed customers to correctly identify the most healthful product when comparing options than the GDA system.

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4.3.2 Country Examples

Added February 2021 Reyes M, Smith Taillie L, Popkin B, et al. Changes in the amount of nutrient of packaged foods and beverages after the initial implementation of the Chilean Law of Food Labelling and Advertising: A nonexperimental prospective study. PLoS medicine. 2020 Jul 28;17(7):e1003220.

The Chilean Food Labeling and Advertising Law, implemented in 2016, mandates the use of front-of-pack warning labels for packaged foods and beverages with added sugars, saturated fats, or sodium that are above established cutoffs, in addition to prohibiting “high in” products from being marketed to children under 14 or sold/served in schools. Data on nutrient information declared on the food labels were collected in Santiago supermarkets and compared pre- and post-implementation of the first phase of the law (warning labels required on products with >800mg sodium per 100g). After implementation of the first phase, the overall proportion of products that met the threshold for a mandatory "high in" warning label significantly decreased from 51% to 44%, mostly in food and beverage groups in which regulatory cutoffs were below the 75th percentile of the nutrient or energy distribution. The proportion of “high in sodium” products (savory spreads, cheeses, ready-to-eat meals, soups, and sausages) reduced from 74% to 27% and the proportion of “high in” sugars products (beverages, milks and milk-based drinks, breakfast cereals, sweet baked products, and sweet and savory spreads) reduced from 80% to 60%. After the implementation of the Chilean law, there was a significant decrease in the amount of sodium and sugars in several groups of packaged foods and beverages (including beverages, breakfast cereals, desserts and ice cream, savory spreads, and cheeses).

*For other Chile papers, see:

Food and Agriculture Organization of the United Nations, Pan American Health Organization, World Health Organization. Approval of a new Food Act in Chile: Process Summary. FAO/WHO. Santiago. 2016. (describes the contents and regulatory process of Chile’s Food Labeling and Advertising Law)

Massri C, Sutherland S, Källestål C, Peña S. Impact of the food-labeling and advertising law banning competitive food and beverages in Chilean public schools, 2014–2016. American journal of public health. 2019 Sep;109(9):1249-54.

Reyes M, Garmendia ML, Olivares S, Aqueveque C, Zacarías I, Corvalán C. Development of the Chilean front-of-package food warning label. BMC Public Health. 2019;19(1). doi:10.1186/s12889-019-7118-1.

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4.4 Knowledge and Behavior Change

Trieu K, McMahon E, Santos JA, et al. Review of behaviour change interventions to reduce population salt intake. International Journal of Behavioral Nutrition and Physical Activity. 2017 Dec;14(1):17.

Overall, 19 of the 22 studies looking at the effectiveness of population-level behavior change interventions on salt reduction reported significantly reduced estimated daily salt intake or improved self-reported salt-lowering behaviors. Of the 22 studies, 14 were health education interventions, 4 were public awareness campaigns, and 4 were multicomponent education interventions (both health education and awareness campaigns). “Of the 12 studies whose outcome was salt intake, 10 demonstrated significant reductions ranging from 0.9 g/d to 4.4 g/d.” The 3 studies showing no significant improvements were all health-education-only programs (as opposed to public awareness campaigns and multi-component interventions). Of the 10 studies classified as higher-quality studies (those with low risk of bias, e.g. selection bias, reporting bias), only 5 found significant effects on salt intake or behaviors based on the more objective outcome assessment method. Results of the study indicate that there is not yet a proven best method of reducing discretionary salt intake.

Adler AJ, Taylor F, Martin N, et al. Reduced dietary salt for the prevention of cardiovascular disease. Cochrane Database of Systematic Reviews. 2014(12).

This review concluded that providing dietary advice to patients to reduce sodium intake had minimal impact, which emphasizes the need for population-wide changes in the options and default quantities of sodium in the commonly consumed foods. Results showed that individual interventions led to small reductions in blood pressure, but it is unclear whether the cost of implementing these interventions is justified. Interventions that do not rely on individual behavior change may prove to be more effective.

Added February 2021 Khalig M, Sommariva S, Bardfield L, Blanco-Metzler A, Benítez G, Saavedra L, Gomes A, Vega J. Salt reduction in Latin America: A Regional Social Marketing & Communication Plan. Project - IDRC 108167 Scaling Up and Evaluating Salt Reduction Policies and Programs in Latin American Countries. 2016-2020 Tres Ríos, Costa Rica: Costa Rican Institute of Research and Teaching in Health and Nutrition (INCIENSA), 2019.

This document compiles lessons from four Latin American countries into a social marketing framework for salt reduction that ties together population-based and individual initiatives to create integrated and holistic salt reduction programs. It highlights a series of creative concepts and communication strategies that aim to decrease demand for salt and other high sodium products. The document identifies five international best practices from social marketing that may help achieve greater impact on current salt reduction efforts: 1) identify one segment of the ‘public’ whose behavior you hope to influence, 2) understand what drives people to consume high salt products, 3) isolate a single, immediate benefit that will make it worthwhile to give up salt and sodium products, 4) select one behavior to change at a time, facilitate that behavior and evaluate the outcome, and 5) choose surprising messages to change behavior.

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4.4.1 Country Examples

Do HT, Santos JA, Trieu K, et al. Effectiveness of a Communication for Behavioral Impact (COMBI) intervention to reduce salt intake in a Vietnamese Province based on estimations from spot urine samples. JCH. 2016 Nov;18(11):1135-42.

In Vietnam, about 80% of salt intake comes from table salt or salty condiments used at home. Therefore, a behavior change approach was taken to reduce population salt intake in one Vietnamese city using the Communication for Behavioral Impact (COMBI) framework. The intervention led to significant decreases in mean salt excretion both from spot and 24-hour urine samples (-0.43g/day and -1.99g/day, respectively). Significant improvements were seen for knowledge and behavioral outcomes, including increased awareness that high salt intake can cause hypertension, heart attack, and stroke and reported reductions to adding salt or sauces in the home or consuming processed foods or dishes high in salt. Mean SBP and DBP decreased significantly (5.93 mm Hg and 3.83 mm Hg, respectively), awareness of hypertensive status improved among those with hypertension (+16.3%), and fewer hypertensive subjects reported not being managed or treated (-14.2%).

Land MA, Wu JH, Selwyn A, et al. Effects of a community-based salt reduction program in a regional Australian population. BMC Public Health. 2016 Dec;16(1):388.

A multi-faceted, community-based salt reduction intervention following the Communication for Behavioral Impact (COMBI) framework was implemented in Australia from 2010 to 2014. It led to significant reductions in mean salt intake of 0.8 g/day as measured by 24-hour urine. Key messages included using the FoodSwitch app, swapping table salt for a salt substitute, using spices instead of salt, and avoiding processed foods. In addition to the 24-hour urine results, significant improvements were found for most knowledge and behavioral indicators, including understanding the importance of lowering salt and using spices for flavoring or the sodium reduced, potassium-rich salt substitute which was provided.

Wentzel-Viljoen E, Steyn K, et al. Evaluation of a mass-media campaign to increase the awareness of the need to reduce discretionary salt use in the South African population. Nutrients. 2017 Nov 12;9(11):1238.

For about 9 months during 2014-2015, a mass media campaign was implemented in South Africa to reduce discretionary salt intake and increase public knowledge on the dangers of high salt intake. Baseline and follow-up surveys were conducted to assess the change in knowledge, attitudes and behavior. 77.8% of the follow-up survey respondents reported having seen the SaltWatch media campaign messages. Knowledge regarding high salt intake and its health outcomes improved significantly. At follow up, “significantly more participants reported that they were taking steps to control salt intake (38% at baseline vs. 59.5% at follow up), especially for reductions in salt used in cooking and at the table, as well as higher use of herbs and spices. No significant changes were found in other behaviors, including avoiding processed foods, looking at salt/sodium labels on food, buying low-salt or low-sodium alternatives, or avoiding eating out. Data was not collected on changes in salt intake.

He FJ, Wu Y, Feng XX, et al. School based education programme to reduce salt intake in children and their families (School-EduSalt): cluster randomised controlled trial. BMJ. 2015 Mar 18;350:h770.

A school-based education program on salt intake in Northern China reduced salt intake by 2.6 grams per day, a 26% reduction (−1.9 g/day in children and −2.9 g/day in adults). The intervention included health education lessons on salt reduction with interactive activities, and students were asked to take the messages home to their families, along with educational materials for the parents. The impact was assessed through a cluster-randomized control trial in 28 primary schools. Although systolic and diastolic blood pressure increased among both the control and intervention groups of adults and children by the end of the trial, the increase was less among the intervention group, with a mean effect of −1.8 mm Hg.

Added February 2021 Sutherland J, Edwards P, Shankar B, Dangour AD. Fewer adults add salt at the table after initiation of a national salt campaign in the UK: a repeated cross-sectional analysis. British journal of nutrition. 2013 Aug;110(3):552-8.

A 2003 national salt reduction campaign in the UK on salt use at the table appears to have led to a reduction in the proportion of adults who reported adding salt at the table (40.1% in 1997 to 31.7% in 2007). After the 2003 national salt reduction campaign, women were 30% less likely to add salt at the table than men (OR 0.71). Differences were also seen for geographical location, household income, and ethnicity. Adults in central and south England, high- and middle-income groups, and the non-white ethnic groups were less likely to add salt at the table than their counterparts.

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4.5 Changing the Environment

Story M, Kaphingst KM, Robinson-O'Brien R, Glanz K. Creating healthy food and eating environments: policy and environmental approaches. Annu. Rev. Public Health. 2008 Apr 21;29:253-72.

Improving the “environmental context and conditions in which people live and make choices” is crucial in improving individual- and population-level dietary behaviors. Promising interventions and policies exist for improving behaviors in a variety of environmental contexts. For example, setting nutrition standards for foods available in schools, increasing fresh fruit-and-vegetable programs in schools, establishing worksite programs to increase availability and decrease the price of healthy food, point-of-purchase promotion and targeted food placement in worksite cafeterias as well as supermarkets, preventing “food deserts” where healthy food is unavailable, smaller portion sizes, and nutrition information at restaurants. Disparities in access to and affordability of healthy food often negatively affect low-income and rural populations. Policies and programs should ensure that healthy options are available, identifiable, and affordable to people of all income levels and all geographic locations. Macro-level agricultural policies, government regulations that affect food pricing, and marketing restrictions should all be aligned with national nutrition goals to ensure healthy food is the default choice.

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4.5.1 Restaurants

Added February 2021 Ding J, Sun Y, Li Y, et al. Systematic Review on International Salt Reduction Policy in Restaurants. International Journal of Environmental Research and Public Health. 2020 Dec 21;17(24):9570

The systematic review provides the first global overview of salt reduction policies in restaurants. Of the 62 policies identified, menu labeling, target setting, and reformulation of recipes were the most common strategies used. Other strategies identified included consumer education, chef training, toolkit delivery, table salt removal, and media campaigns. Most policies focused on chain restaurants, and less than half (44%) were mandatory. There was limited evidence of the effectiveness of these strategies after implementation. Only 17 studies conducted an evaluation post-implementation, with 6 showing positive impacts, 8 little to no effect, and 3 simply described the overall salt reduction effect (not focused on restaurants). The positive impacts mainly came from menu labeling policies, which showed lower sodium content in meals, increased awareness of chefs and owners, and improved consumer choices. More research needs to be done to determine the feasibility and effectiveness of implementing sodium reduction policies in restaurants.

Added February 2021 Ma GX, Shive SE, Zhang G, et al. Evaluation of a healthy Chinese take-out sodium-reduction initiative in Philadelphia low-income communities and neighborhoods. Public Health Reports. 2018 Jul;133(4):472-80.

The Healthy Chinese Take-Out initiative (HCTI) aimed to reduce the sodium content of dishes prepared by Chinese take-out restaurants in low-income urban communities in Philadelphia, USA through a chef training program. An evaluation in a subset of participating restaurants found a significant reduction in sodium in the three most popular dishes: reductions were 36% in shrimp and broccoli (from 5.5 to 3.5 mg/g), 28% reduction in chicken lo mein (from 5.7 to 4.1 mg/g), and 19% in General Tso’s chicken (from 5.9 to 4.8 mg/g). Chefs’ knowledge of the health consequences of sodium overconsumption increased significantly after the training and was maintained from through the final evaluation 36 months later. While chefs’ perceptions of the need to prepare low-sodium dishes and of their ability to do so increased significantly from baseline to post-training (P < .001), it returned to baseline levels by the final evaluation.

Added February 2021 Anekwe AV, Lent M, Kennelly MO, Angell SY. New York City's sodium warning regulation: from conception to enforcement. American journal of public health. 2019 Sep 1;109(9):1191-2.

In 2015, the New York City Department of Health (DOH) implemented and enforced a regulation requiring warning labels on high sodium menu items (>2,300 mg/item) in chain restaurants. To create awareness for the regulation and foster restaurant compliance, the DOH held a press event with industry and mailed guidance to restaurants on how to meet the regulation requirements. They also rolled out a media campaign to educate the public about the warning icons in English and Spanish via print, television, and online media platforms. Days after the regulation went into effect, the National Restaurant Association filed a lawsuit to block its implementation. After an 18-month legal battle, the city won the lawsuit and enforcement began in 2016. The key steps for designing a high-sodium warning policy include designing the label, defining the sodium threshold above which consumers should be alerted, and determining which restaurants would be required to comply.

Added February 2021 Ma J, Lee S, Kim K, Lee YK. Sodium reduction in South Korean restaurants: A Daegu-based intervention project. Asia Pacific Journal of Clinical Nutrition. 2020 Jul;29(2):404_

In 2015, the Korean Ministry of Food and Drug Safety launched a sodium reduction project in restaurants to reduce the daily sodium intake by 3,500 mg by 2020. Restaurants were designated as sodium reduction restaurants if 20% of the restaurant’s menu items reduced their sodium content (per serving) by 10% to less than 1300 mg or by more than 30% for menu items with more than 2,000 mg per serving. The study compares the sodium content of the restaurants that implemented the sodium changes to their menus before and after the project and evaluated the restaurants' sodium reduction practices. On average, post intervention, the sodium content per serving decreased significantly from 1470 mg to 980 mg. The food groups with the highest sodium reduction rate were broth (46%), stir-fried dishes (39.5%), soups (35.8%), grilled dishes (34.8%), porridge dishes (33.5%), cooked rice dishes (31.8%) and steamed dishes (31.5%). Post intervention surveys showed that 70.6% of customers were ‘satisfied’ or ‘very satisfied’ with the sodium reduced menu. The findings from the study suggest that it is feasible to reduce the sodium content in restaurant food.

Added February 2021 Musicus AA, Moran AJ, Lawman HG, Roberto CA. Online randomized controlled trials of restaurant sodium warning labels. American journal of preventive medicine. 2019 Dec 1;57(6):e181-93.

Four different online experiments were performed to determine the influence of different designs of sodium warning labels on the customers’ hypothetical meal choices, perceptions, and sodium knowledge. In experiments 1-3, all warning labels consistently reduced the average sodium ordered (by 19−81 mg) versus the control, the largest being traffic light and red stop sign labels (by 68 mg and 46 mg, respectively), but these results were not statistically significant. The 4th experiment tested the top performers from experiments 1-3 (traffic light and red stop sign warnings) against a control and found statistically significant reductions in average sodium ordered (-68 mg or -4.5% for traffic lights and -46 mg or -3.0% for red stop signs) as well as a reduction in the percentage of participants choosing a high-sodium items. Overall, participants who saw any type of warning label perceived high sodium meals to be saltier and reported a stronger belief that eating high sodium meals would increase their risk for high blood pressure (all p <0.001). Although these effects may appear relatively small, they may be meaningful at the population level.

4.5.2 Healthy Public Food Procurement

Added February 2021 WHO. Framework: Action framework for developing and implementing public food procurement and service policies for a healthy diet. Geneva, World Health Organization (WHO), 2021. Available at: https://www.who.int/publications/i/item/9789240018341

Healthy public food procurement and service policies set criteria for the service and sale of food in public settings or for government expenditures on food in order to increase the availability of foods that promote healthy diets and limit food that contributes to an unhealthy diet. The action framework serves as a tool for governments to develop, implement, monitor, and evaluate public food procurement and serve policies that align with the core principles of a healthy diet, which include 1) limiting sodium consumption and ensuring that salt is iodized; 2) limiting sugar intake; 3) shifting consumption of fat from saturated to unsaturated; 4) eliminating trans fat; 5) increasing consumption of whole grains, vegetables, fruit, nuts, and pulses; and 6) ensuring availability of free and safe drinking water. The action framework proposes 4 key policy steps for developing a public food procurement and service policy: 1) policy preparation outlines the key steps to take when developing or revising a healthy public food procurement and service policy; 2) policy development describes the steps of the policy development process which includes defining the purpose, scope, and nutrition; 3) policy implementation reviews the key steps to support and ensure full policy implementation; and 4) monitoring, enforcement, and evaluation guides the process of monitoring and enforcing the policy, as well as conducting a policy evaluation to determine whether the policy is effectively implemented.

Niebylski ML, Lu T, Campbell NR, et al. Healthy food procurement policies and their impact. International journal of environmental research and public health. 2014 Mar 3;11(3):2608-27.

“Healthy food procurement programs found in this review were nearly always effective at increasing availability of healthier food and decreasing that of less healthy food; contributing to the increased purchases of healthier foods and lower purchases of food high in fat, sodium and sugar”. A systematic review evaluated the impact of such policies on healthy eating and health outcomes and included procurement policies implemented in schools (19 studies), worksites (6 studies), remote communities (3 studies), and 6 studies in other settings including hospitals, care homes, correctional facilities, government institutions. No policy intervention identified was unsuccessful. Two studies which included health outcomes found improvement in blood pressure and BMI. Many procurement policies were strengthened by allied interventions such as educational programs or subsidies for healthy foods. Additionally, procurement policies may lead to reformulation of products to be healthier, although more research is needed in this area.

4.5.2.1 Country Examples

Lederer A, Curtis CJ, Silver LD, Angell SY. Toward a healthier city: nutrition standards for New York City government. AJPM. 2014 Apr 1;46(4):423-8.

In 2008, New York City Mayor Bloomberg signed an Executive Order which led to the development of the NYC Standards for Meals/Snacks Purchased and Served, a policy requiring all city agencies to follow the standards (including limits for sodium) for all food that is purchased, prepared, and/or served by the agency, covering more than 260 million meals and snacks per year. The standards were developed by a Food Procurement Workgroup, with representation from all relevant city agencies and the NYC Health Department serving as technical advisor. Elements which led to successful implementation of the standards included support from a high-level central authority, providing extensive technical assistance to agencies, incorporating the standards into all city agency contracts which involved food, and developing regular progress reports detailing agencies’ compliance with the standards.

Added February 2021 Gase LN, Kuo T, Dunet D, et al. Estimating the potential health impact and costs of implementing a local policy for food procurement to reduce the consumption of sodium in the county of Los Angeles. American journal of public health. 2011 Aug;101(8):1501-7.

This study modeled the potential costs and effects on daily sodium consumption and related health outcomes of reducing the sodium content in food served in six types of public settings operated by the government of Los Angeles County, California. In total, the policy would affect 13,183 adults and 24,000 children who are served by venues operated by Los Angeles County (notably schools were not included). The average daily sodium consumption would be reduced between 220 mg (6% reduction) and 773 mg (23% reduction), depending on the settings and approach used. Systolic blood pressure reductions among adults would fall between 0.45-1.59 mmHg, leading to a 5% decrease in the prevalence of uncontrolled hypertension, as well as an annual $629,724 savings in direct health care costs. The estimated 1 -year start-up costs for Los Angeles County to implement the policy ranged from $227,753 to $1,723,539, based on the uncertainty regarding the potential changes in food costs.

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4.5.2.2 Venues
4.5.2.2.1 Schools

Ellison RC, Capper AL, Stephenson WP, et al. Effects on blood pressure of a decrease in sodium use in institutional food preparation: the Exeter-Andover Project. Journal of Clinical Epidemiology. 1989 Jan 1;42(3):201-8.

A six-month boarding school intervention to reduce sodium intake through changes to food purchasing and preparation led to a 15-20% reduction in sodium intake at the two participating schools. No information or directives were given to students throughout the intervention. The two schools each served as an intervention and control site during alternating years. Students selected for monitoring were asked to keep a 24-hour food diary once a week at scheduled intervals during the intervention and measured their blood pressure at the beginning and end of the school year. After adjusting for sex and initial blood pressure, “the net effect on both systolic and diastolic blood pressure produced by the 24 weeks of dietary intervention is estimated at approximately -1.0 mmHg for males and -2.5 mmHg for females”.

Spence S, Delve J, Stamp E, et al. The impact of food and nutrient-based standards on primary school children’s lunch and total dietary intake: a natural experimental evaluation of government policy in England. Plos One. 2013 Oct 30;8(10):e78298.

In 2006, food- and nutrient-based standards were mandated for primary schools in England. A study at 12 primary schools found that “Implementation of school food policy standards was associated with significant improvements in the nutritional content of school lunches.” Post-implementation, mean daily intake of sodium fell by 67 mg per day. Children who ate the school lunch consumed less sodium (-128 mg) than children eating a packed lunch. Additional improvements were seen post-implementation in reduced energy, absolute intakes of fat, saturated fat, and non-milk extrinsic sugars in packed and school lunches. Children who ate school lunches had “a lower percent energy derived from fat and saturated fat, but more carbohydrate, protein, non-starch polysaccharides, vitamin C and folate in their total diet than children who ate a packed lunch”.

World Food Programme. Smart School Meals: Nutrition-sensitive national programmes in Latin America and the Caribbean. 2017. Rome: WFP.

Nearly all countries in the Latin America and the Caribbean region implement school meals programs; however, “despite undisputed achievements and progress, the nutritional potential of school meals is often underutilized”. Many of these programs could be strengthened by incorporating specific nutrition criteria to limit unhealthy nutrients such as salt, fats, and sugar.

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4.5.2.2.2 Hospitals

Moran A, Lederer A, Curtis CJ. Use of nutrition standards to improve nutritional quality of hospital patient meals: findings from New York City’s Healthy Hospital Food Initiative. Journal of the Academy of Nutrition and Dietetics. 2015 Nov 1;115(11):1847-54.

The New York City Health Department implemented the Healthy Hospital Food Initiative (HHFI) from 2010-2014, which included nutrient-based food procurement standards and standards for patient meals. A study comparing the nutritional composition of regular-diet patient meals in 8 hospitals before and after the initiative found that “Median sodium content decreased 19%, from 2,636mg to 2,149mg per day.” Additionally, fiber increased by 25%, the percentage of calories from fat decreased by 24% and from saturated fat by 21%, and daily dessert offerings decreased 92%. At follow-up, nutrition content across all hospital menus improved and either met or exceeded the minimum HHFI standards.

Ministry of Health, Population and Public Health. Sodium reduction in health‐care facilities – B.C.'s experience. 2016. Healthy Living and Health Promotion, Ministry of Health, Population and Public Health, Victoria, Canada. 2016.

The British Columbia health authority developed and implemented provincial sodium guidelines and procurement policies for food service operations in BC government health care facilities between 2011 and 2016. The initiative was carried out in three phases: 1) developing sodium guidelines and procurement policies (5 months), 2) stakeholder engagement and implementation (3 years), and 3) final push to reach the target of 2300mg per day/meal (adults) and 1818-2300 mg (pediatric) (1 year). Results showed that by 2016, adult meals had 28% less sodium than at baseline (3372mg to 2372mg), although the final reduction target of 2300mg was not met. Due to various implementation, the date for reaching the target levels was extended to 2021, and sodium targets were lowered to 2,300 – 2,700 mg during the interim.

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4.6 Salt Substitutes

Added February 2021 Greer RC, Marklund M, Anderson CA, et al. Potassium-enriched salt substitutes as a means to lower blood pressure: benefits and risks. Hypertension. 2020 Feb;75(2):266-74.

The use of potassium-enriched salt substitutes as a public health strategy to lower sodium consumption could help reduce sodium intake and increase potassium intake at the population level. Evidence shows that replacement of sodium chloride with potassium-enriched salt substitutes lowers both systolic and diastolic blood pressure, by -5.58 and -2.88, respectfully, with greater blood pressure reductions in patients with high blood pressure. The main risk for widespread use of potassium-enriched salt substitutes is the potential for hyperkalemia in people with impaired kidney function or who are taking medications that impair potassium excretion. However, evidence linking potassium-enriched salt substitutes to the occurrence of hyperkalemia is limited to a few case reports; trials of salt substitutes of have reported some adverse events but have mostly excluded at risk individuals. More research on the population-wide impact of replacing sodium chloride with potassium-enriched salt substitutes is needed.

Hernandez AV, Emonds EE, Chen BA, et al. Effect of low-sodium salt substitutes on blood pressure, detected hypertension, stroke and mortality. Heart. 2019 Jan 19:heartjnl-2018.

Meta-analysis of 21 randomized controlled trials showed that low-sodium salts significantly lowered both systolic and diastolic blood pressure when compared to regular salt (by 7.8 and 4.0 mm Hg respectively. No conclusions could be made on the effects of salt substitutes on stroke or cardiovascular-related mortality due to the scarcity of data. Low-sodium salt substitutes ranged from 0% to 97% NaCl content. Urinary sodium excretion decreased by −35.82 mmol/day on average, and increases were found for urinary potassium excretion. No other significant intervention effects were found for blood glucose, total cholesterol, triglycerides and BMI. Outcomes were not statistically different for any outcomes across hypertensive, mixed, and normotensive populations.

Chang HY, Hu YW, Yue CS, et al. Effect of potassium-enriched salt on cardiovascular mortality and medical expenses of elderly men. AJCN. 2006 Jun 1;83(6):1289-96.

“Potassium-enriched salt reduced the CVD mortality hazard ratio to ~60% that of the control group” in a randomized control trial of the effects of potassium-enriched salt (49% sodium chloride, 49% potassium chloride) on CVD outcomes in a veteran retirement home in Taiwan. Residents in the experimental group had a longer life expectancy (0.2-0.9 years longer) and significantly lower expenditures on CVD-related inpatient care. Residents were assigned to receive meals from kitchens randomized to either an experimental (potassium salt) group or control (regular salt) group and were followed for 31 months on average. Residents with high serum creatinine concentrations were excluded.

Li N, Yan LL, Niu W, et al. The effects of a community-based sodium reduction program in rural China–a cluster-randomized trial. PloS One. 2016 Dec 9;11(12):e0166620.

A cluster-randomized trial in 120 villages in rural northern China measured the effects of providing access to a low-sodium, potassium-based salt substitute along with health education on sodium reduction. Of the 60 villages receiving the intervention, half also received a price subsidy for the low-sodium salt. At the end of the trial, “mean urinary sodium excretion in intervention compared with control villages was 5.5% lower (-14mmol/day, 95% confidence interval -26 to -1; p = 0.03), potassium excretion was 16% higher (+7mmol/day, +4 to +10; p<0.001), and sodium to potassium ratio 15% lower (-0.9, -1.2 to -0.5; p<0.001).” Use of low-sodium salts was twice as high among intervention sites receiving the price subsidy than intervention sites not receiving the subsidy; the estimated effect on urinary sodium was not statistically significant, possibly due to lower sample size. Knowledge relating to salt and salt substitute improved in the intervention group.

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4.6.1 Country Examples

Added February 2021 Bernabe-Ortiz A, y Rosas VG, Ponce-Lucero V, et al. Effect of salt substitution on community-wide blood pressure and hypertension incidence. Nature medicine. 2020 Mar;26(3):374-8.

This stepped-wedge cluster trial in Peru found that individuals in households randomized to receive a salt substitute (75% NaCl and 25% KCl) had an average reduction of 1.29 mmHg in systolic blood pressure and 0.76 mmHg in diastolic blood pressure compared with controls. Among participants who were hypertensive at baseline, there was an average reduction in systolic blood pressure of 1.92 mmHg and 1.18 mmHg in diastolic blood pressure. Further, participants were 51% less likely to develop hypertension in the intervention period than in the control period. Urinary analysis showed an increase in mean potassium intake (mean difference of 0.63 g) but no change in sodium intake. While the reductions in blood pressure are modest, they carry large public health gains. To increase uptake of the salt substitute, investigators developed a brand identity (named by the local community) and a social marketing campaign, which was conducted before and during the intervention.

Added February 2021 Marklund M, Singh G, Greer R, Cudhea F, Matsushita K, Micha R, Brady T, Zhao D, Huang L, Tian M, Cobb L. Estimated population wide benefits and risks in China of lowering sodium through potassium enriched salt substitution: modelling study. bmj. 2020 Apr 22;369.

This modelling study shows that replacing discretionary salt with a potassium-enriched salt substitute could potentially save 450,000 lives from cardiovascular disease in China annually. The study used comparative risk assessment models to estimate the benefits, harms, and net effects of a nationwide intervention to replace discretionary dietary salt (NaCl) with potassium enriched salt substitutes (20-30% potassium chloride), projecting the prevention of 461,000 deaths due to cardiovascular disease, 208,000 due to stroke and 175,000 due to ischemic heart disease, as well as 740,000 non-fatal cardiovascular events annually. The intervention also estimated 21,000 fewer deaths in individuals with chronic kidney disease. The study noted that due to the risks associated with increased potassium, the intervention could potentially produce an estimated 11,000 additional deaths related to hyperkalemia in individuals with chronic kidney disease. Overall, the study suggests that potassium-enriched salt substitutes can have a large effect on the burden of cardiovascular disease in China and potentially other countries with a high discretionary salt intake.

4.7 Taxation on High Sodium Foods

Added February 2021 Dodd R, Santos JA, Tan M, Campbell NR, Ni Mhurchu C, Cobb L, Jacobson MF, He FJ, Trieu K, Osornprasop S, Webster J. Effectiveness and feasibility of taxing salt and foods high in sodium: A systematic review of the evidence. Advances in Nutrition. 2020 Nov;11(6):1616-30.

This systematic review provides a narrative summary of the evidence on salt taxation and provides an overview of "real-world" implementation of salt taxes to date. The studies included in this review used 3 taxation strategies to address high salt consumption: taxing salt itself, taxing food high in salt, and taxing unhealthy foods. While there are some real-world evaluations of the potential effectiveness and cost-effectiveness of salt taxation, most of evidence comes from modeling studies. Most studies modeled the impact on salt consumption by estimating either household purchase of food high in salt or individual salt intake. Some modeling studies suggested that food taxes can have unintended outcomes such as increased consumption of unhealthy, untaxed substitutes. Modeling studies that combined taxes for unhealthy foods with subsidies for fruits and vegetables found greater benefits than taxation alone. Two real world studies (from Hungary and Tonga) evaluated the impact of taxation measures on personal consumption and reported modest positive results. In Hungary, 11–16% of those consuming salty snacks and condiments reported changing their behavior due to the tax, but of these, only 5% switched to healthier alternatives. Findings suggest that taxing all foods based on their salt content may be more impactful than taxing specific products high in salt. There is a need for more research, especially real-world studies, in order to better assess the impact of salt taxes.

4.7.1 Country Examples

Added February 2021 WHO/National Institute for Food and Nutrition Science. Assessment of the impact of a public health product tax, Final report. Budapest; World Health Organization Regional Office for Europe, 2015.

In 2011, Hungary’s Public Health Product Tax (PHPT) was enforced, with the aim to reduce consumption of unhealthy food products, promote a healthy diet and make healthy food choices accessible, and to improve public funding for health care services, especially public health programs. An impact assessment of the tax suggests that consumers who purchased salty snacks and pre-packaged sweets changed their consumption, by 16% and 14% respectively, while 11% of people who ate powdered soup and salty condiments changed their consumption. Higher prices were cited as the reason for changing consumption of pre-packaged sweets and salty snacks by 81% of people who changed their consumption in 2012 and by 66% and 56%, respectively, in 2014. Those who reduced their consumption were two to three times more aware that the product was unhealthy.

Added February 2021 Batis C, Rivera JA, Popkin BM, Taillie LS. First-year evaluation of Mexico’s tax on nonessential energy-dense foods: an observational study. PLoS medicine. 2016 Jul 5;13(7):e1002057.

In January 2014, the Mexican government implemented an 8% tax on nonessential foods with energy density > 275 kcal/100 g, including salty snacks and junk food, and a peso-per-liter tax on sugar-sweetened beverages (SSBs). The study examines changes in the volume of taxed and untaxed food purchases after both taxes were implemented. On average, the total volume of taxed purchases had an absolute decline of 25 g per capita per month (p < 0.05), or a -5.1% relative change beyond what would have been expected based on pre-tax trends. In 2014, low SES households purchased on average 10.2% less taxed foods than expected (p < 0.05), whereas medium SES households purchased 5.8% less taxed foods (p < 0.05), and high-income households’ purchases did not change. The greatest changes in total purchases were observed among taxed salty snacks (-6.3% below expected, p < 0.05) and taxed cereal-based sweets (-5.2% below expected, p < 0.05), while taxed non-cereal-based sweets and ready-to-eat cereals did not change.

Added February 2021 Cobiac LJ, Tam K, Veerman L, Blakely T. Taxes and subsidies for improving diet and population health in Australia: a cost-effectiveness modelling study. PLoS medicine. 2017 Feb 14;14(2):e1002232.

This study used a cost-effectiveness model to evaluate a range of food and drink taxes and subsidies to determine an optimally cost-effective package of tax and subsidy options for the Australian population. The five intervention options modeled included: 1) taxing saturated fat, 2) taxing excess salt in processed food, 3) taxing sugar-sweetened beverages, 4) subsidizing fruits and vegetables, and 5) taxing processed foods high in sugar. Of the 5 taxes and subsidies, only the sugar tax led to the most improvements in dietary measures - a reduction in sodium and energy intake and an increase in fruit and vegetable intake. The excess salt tax had the next highest impact, leading to reductions in sodium intake (-67 mg/day) and energy intake (-161 kJ/day). Individually, the taxes examined all led to an improvement in population health, ranging from 12,000 - 270,000 DALYs averted in the Australian population. The combination of all five tax and subsidy interventions led to 470,000 DALYs averted and a net cost saving of AU$3.4 billion, with a 100% probability of cost-savings.

Appendix I: Sodium Conversion Values

Salt Sodium
Grams Teaspoons mgs mmols
6 1 2300* 100*
5 NA 2000* 87
0.0585 NA 23 1
2.5* NA 1000 43.5
1 NA 394 17.1

*approximate

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