Review Article | Published:

Role of salt intake in prevention of cardiovascular disease: controversies and challenges

Nature Reviews Cardiologyvolume 15pages371377 (2018) | Download Citation

Abstract

Strong evidence indicates that reduction of salt intake lowers blood pressure and reduces the risk of cardiovascular disease (CVD). The WHO has set a global target of reducing the population salt intake from the current level of approximately 10 g daily to <5 g daily. This recommendation has been challenged by several studies, including cohort studies, which have suggested a J-shaped relationship between salt intake and CVD risk. However, these studies had severe methodological problems, such as reverse causality and measurement error due to assessment of salt intake by spot urine. Consequently, findings from such studies should not be used to derail vital public health policy. Gradual, stepwise salt reduction as recommended by the WHO remains an achievable, affordable, effective, and important strategy to prevent CVD worldwide. The question now is how to reduce population salt intake. In most developed countries, salt reduction can be achieved by a gradual and sustained reduction in the amount of salt added to food by the food industry. The UK has pioneered a successful salt-reduction programme by setting incremental targets for >85 categories of food; many other developed countries are following the UK’s lead. In developing countries where most of the salt is added by consumers, public health campaigns have a major role. Every country should adopt a coherent, workable strategy. Even a modest reduction in salt intake across the whole population can lead to a major improvement in public health and cost savings.

Key points

  • Salt reduction causes a dose-dependent reduction in blood pressure: within the range of 3–12 g daily, the lower the salt intake, the lower the blood pressure.

  • Prospective cohort studies with salt intake measured by multiple 24-h urine collections demonstrate a direct linear relationship with cardiovascular events and all-cause mortality, down to a daily salt intake of 3 g.

  • The totality of the evidence strongly supports a population-wide reduction in salt intake; paradoxical J-shaped findings from studies with methodological problems should not derail action to reduce salt consumption.

  • Every country should implement a strategy to reduce daily salt intake to the WHO target of 5 g; this action will result in major public health improvements and cost savings.

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Consensus Action on Salt and Health: http://www.actiononsalt.org.uk/

References

  1. 1.

    Forouzanfar, M. H. et al. Global burden of hypertension and systolic blood pressure of at least 110 to 115 mmHg, 1990–2015. JAMA 317, 165–182 (2017).

  2. 2.

    Lim, S. S. et al. A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet 380, 2224–2260 (2012).

  3. 3.

    Lewington, S., Clarke, R., Qizilbash, N., Peto, R. & Collins, R. Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies. Lancet 360, 1903–1193 (2002).

  4. 4.

    He, F. J. & MacGregor, G. A. Reducing population salt intake worldwide: from evidence to implementation. Prog. Cardiovasc. Dis. 52, 363–382 (2010).

  5. 5.

    He, F. J., Li, J. & MacGregor, G. A. Effect of longer term modest salt reduction on blood pressure: Cochrane systematic review and meta-analysis of randomised trials. BMJ 346, f1325 (2013).

  6. 6.

    Aburto, N. J. et al. Effect of lower sodium intake on health: systematic review and meta-analyses. BMJ 346, f1326 (2013).

  7. 7.

    He, F. J. & MacGregor, G. A. Salt reduction lowers cardiovascular risk: meta-analysis of outcome trials. Lancet 378, 380–382 (2011).

  8. 8.

    Brown, I. J., Tzoulaki, I., Candeias, V. & Elliott, P. Salt intakes around the world: implications for public health. Int. J. Epidemiol. 38, 791–813 (2009).

  9. 9.

    Powles, J. et al. 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 3, e003733 (2013).

  10. 10.

    World Health Organization. WHO issues new guidance on dietary salt and potassium. WHO Media Centre http://www.who.int/mediacentre/news/notes/2013/salt_potassium_20130131/en/ (2013).

  11. 11.

    World Health Organization. Sixty-sixth World Health Assembly: Follow-up to the Political Declaration of the High-level Meeting of the General Assembly on the Prevention and Control of Non-communicable Diseases. WHO Governing Body Documentation http://apps.who.int/gb/ebwha/pdf_files/WHA66/A66_R10-en.pdf (2013).

  12. 12.

    Intersalt Cooperative Research Group. Intersalt: an international study of electrolyte excretion and blood pressure. Results for 24 h urinary sodium and potassium excretion. BMJ 297, 319–328 (1988).

  13. 13.

    Poulter, N. R. et al. The Kenyan Luo migration study: observations on the initiation of a rise in blood pressure. BMJ 300, 967–972 (1990).

  14. 14.

    Forte, J. G., Miguel, J. M., Miguel, M. J., de Padua, F. & Rose, G. Salt and blood pressure: a community trial. J. Hum. Hypertens. 3, 179–184 (1989).

  15. 15.

    Graudal, N. A., Hubeck-Graudal, T. & Jurgens, G. Effects of low sodium diet versus high sodium diet on blood pressure, renin, aldosterone, catecholamines, cholesterol, and triglyceride. Cochrane Database Syst. Rev. 4, CD004022 (2017).

  16. 16.

    Rhee, O. J. et al. Effect of sodium intake on renin level: Analysis of general population and meta-analysis of randomized controlled trials. Int. J. Cardiol. 215, 120–126 (2016).

  17. 17.

    The ALLHAT Officers and Coordinators for the ALLHAT Collaborative Research Group. Major outcomes in high-risk hypertensive patients randomized to angiotensin-converting enzyme inhibitor or calcium channel blocker versus diuretic: the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). JAMA 288, 2981–2997 (2002).

  18. 18.

    Juraschek, S. P. et al. Time course of change in blood pressure from sodium reduction and the DASH diet. Hypertension 70, 923–929 (2017).

  19. 19.

    The Trials of Hypertension Prevention Collaborative Research Group. The effects of nonpharmacologic interventions on blood pressure of persons with high normal levels. Results of the Trials of Hypertension Prevention, Phase I. JAMA 267, 1213–1220 (1992).

  20. 20.

    The Trials of Hypertension Prevention Collaborative Research Group. Effects of weight loss and sodium reduction intervention on blood pressure and hypertension incidence in overweight people with high-normal blood pressure. The Trials of Hypertension Prevention, phase II. Arch. Intern. Med. 157, 657–667 (1997).

  21. 21.

    He, F. J., Pombo-Rodrigues, S. & MacGregor, G. A. Salt reduction in England from 2003 to 2011: its relationship to blood pressure, stroke and ischaemic heart disease mortality. BMJ Open 4, e004549 (2014).

  22. 22.

    Mozaffarian, D. et al. Global sodium consumption and death from cardiovascular causes. N. Engl. J. Med. 371, 624–634 (2014).

  23. 23.

    MacGregor, G. A., Markandu, N. D., Sagnella, G. A., Singer, D. R. & Cappuccio, F. P. Double-blind study of three sodium intakes and long-term effects of sodium restriction in essential hypertension. Lancet 334, 1244–1247 (1989).

  24. 24.

    Sacks, F. M. et al. Effects on blood pressure of reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH) diet. N. Engl. J. Med. 344, 3–10 (2001).

  25. 25.

    Denton, D. et al. The effect of increased salt intake on blood pressure of chimpanzees. Nat. Med. 1, 1009–1016 (1995).

  26. 26.

    Elliott, P. et al. Change in salt intake affects blood pressure of chimpanzees: implications for human populations. Circulation 116, 1563–1568 (2007).

  27. 27.

    NICE (The National Institute for Health and Care Excellence). Cardiovascular disease prevention. NICE http://guidance.nice.org.uk/PH25 (2010).

  28. 28.

    US Department of Agriculture, Center for Nutrition Policy and Promotion. Dietary Guidelines for Americans 2015–2020 http://www.cnpp.usda.gov/DietaryGuidelines (2018).

  29. 29.

    He, F. J. & MacGregor, G. A. How far should salt intake be reduced? Hypertension 42, 1093–1099 (2003).

  30. 30.

    Strazzullo, P., D’Elia, L., Kandala, N. B. & Cappuccio, F. P. Salt intake, stroke, and cardiovascular disease: meta-analysis of prospective studies. BMJ 339, b4567 (2009).

  31. 31.

    Poggio, R. et al. Daily sodium consumption and CVD mortality in the general population: systematic review and meta-analysis of prospective studies. Public Health Nutr. 18, 695–704 (2015).

  32. 32.

    O’Donnell, M. et al. Urinary sodium and potassium excretion, mortality, and cardiovascular events. N. Engl. J. Med. 371, 612–623 (2014).

  33. 33.

    O’Donnell, M. J. et al. Urinary sodium and potassium excretion and risk of cardiovascular events. JAMA 306, 2229–2238 (2011).

  34. 34.

    Mente, A. et al. Associations of urinary sodium excretion with cardiovascular events in individuals with and without hypertension: a pooled analysis of data from four studies. Lancet 388, 465–475 (2016).

  35. 35.

    Graudal, N., Jurgens, G., Baslund, B. & Alderman, M. H. Compared with usual sodium intake, low- and excessive-sodium diets are associated with increased mortality: a meta-analysis. Am. J. Hypertens. 27, 1129–1137 (2014).

  36. 36.

    Mancia, G. et al. The technical report on sodium intake and cardiovascular disease in low- and middle-income countries by the joint working group of the World Heart Federation, the European Society of Hypertension and the European Public Health Association. Eur. Heart J. 38, 712–719 (2017).

  37. 37.

    Cappuccio, F. P. & Campbell, N. R. Population dietary salt reduction and the risk of cardiovascular disease: a commentary on recent evidence. J. Clin. Hypertens. 19, 4–5 (2017).

  38. 38.

    He, F. J. & MacGregor, G. A. Hypertension: Salt: flawed research should not divert actions to reduce intake. Nat. Rev. Nephrol. 12, 514–515 (2016).

  39. 39.

    Cobb, L. K. et al. Methodological issues in cohort studies that relate sodium intake to cardiovascular disease outcomes: a Science Advisory From the American Heart Association. Circulation 129, 1173–1186 (2014).

  40. 40.

    Whelton, P. K. et al. Sodium, blood pressure, and cardiovascular disease: further evidence supporting the American Heart Association sodium reduction recommendations. Circulation 126, 2880–2889 (2012).

  41. 41.

    Cogswell, M. E., Mugavero, K., Bowman, B. A. & Frieden, T. R. Dietary sodium and cardiovascular disease risk — measurement matters. N. Engl. J. Med. 375, 580–586 (2016).

  42. 42.

    Ji, C. et al. Systematic review of studies comparing 24-hour and spot urine collections for estimating population salt intake. Rev. Panam. Salud Publ. 32, 307–315 (2012).

  43. 43.

    Wang, C. Y. et al. Urinary excretion of sodium, potassium, and chloride, but not iodine, varies by timing of collection in a 24-hour calibration study. J. Nutr. 143, 1276–7682 (2013).

  44. 44.

    Suckling, R. J., He, F. J., Markandu, N. D. & MacGregor, G. A. Dietary salt influences postprandial plasma sodium concentration and systolic blood pressure. Kidney Int. 81, 407–411 (2012).

  45. 45.

    Ji, C., Miller, M. A., Venezia, A., Strazzullo, P. & Cappuccio, F. P. Comparisons of spot versus 24-h urine samples for estimating population salt intake: validation study in two independent samples of adults in Britain and Italy. Nutr. Metab. Cardiovasc. Dis. 24, 140–147 (2014).

  46. 46.

    Polonia, J., Lobo, M. F., Martins, L., Pinto, F. & Nazare, J. Estimation of populational 24-h urinary sodium and potassium excretion from spot urine samples: evaluation of four formulas in a large national representative population. J. Hypertens. 35, 477–486 (2017).

  47. 47.

    Armanini, D. et al. Considerations for the assessment of salt intake by urinary sodium excretion in hypertensive patients. J. Clin. Hypertens. 18, 1143–1145 (2016).

  48. 48.

    Kawasaki, T., Itoh, K., Uezono, K. & Sasaki, H. A simple method for estimating 24 h urinary sodium and potassium excretion from second morning voiding urine specimen in adults. Clin. Exp. Pharmacol. Physiol. 20, 7–14 (1993).

  49. 49.

    Liu, K. et al. Assessment of the association between habitual salt intake and high blood pressure: methodological problems. Am. J. Epidemiol. 110, 219–226 (1979).

  50. 50.

    Cogswell, M. E. et al. Use of urine biomarkers to assess sodium intake: challenges and opportunities. Annu. Rev. Nutr. 35, 349–387 (2015).

  51. 51.

    Birukov, A. et al. Ultra-long-term human salt balance studies reveal interrelations between sodium, potassium, and chloride intake and excretion. Am. J. Clin. Nutr. 104, 49–57 (2016).

  52. 52.

    Sun, Q. et al. Reproducibility of urinary biomarkers in multiple 24-h urine samples. Am. J. Clin. Nutr. 105, 159–168 (2017).

  53. 53.

    Cook, N. R., Appel, L. J. & Whelton, P. K. Lower levels of sodium intake and reduced cardiovascular risk. Circulation 129, 981–989 (2014).

  54. 54.

    Mills, K. T. et al. Sodium excretion and the risk of cardiovascular disease in patients with chronic kidney disease. JAMA 315, 2200–2210 (2016).

  55. 55.

    Olde Engberink, R. H. G. 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 136, 917–926 (2017).

  56. 56.

    Cook, N. R., Appel, L. J. & Whelton, P. K. Sodium intake and all-cause mortality over 20 years in the trials of hypertension prevention. J. Am. Coll. Cardiol. 68, 1609–1617 (2016).

  57. 57.

    Ettehad, D. et al. Blood pressure lowering for prevention of cardiovascular disease and death: a systematic review and meta-analysis. Lancet 387, 957–967 (2016).

  58. 58.

    Karppanen, H. & Mervaala, E. Sodium intake and hypertension. Prog. Cardiovasc. Dis. 49, 59–75 (2006).

  59. 59.

    Laatikainen, T. et al. Explaining the decline in coronary heart disease mortality in Finland between 1982 and 1997. Am. J. Epidemiol. 162, 764–773 (2005).

  60. 60.

    Sasaki, N. in Prophylactic Approach to Hypertensive Diseases (eds Yamori, Y., Lovenberg, W. & Freis, E. D.) 467–474 (Raven Press, New York, 1979).

  61. 61.

    Pietinen, P., Valsta, L. M., Hirvonen, T. & Sinkko, H. Labelling the salt content in foods: a useful tool in reducing sodium intake in Finland. Public Health Nutr. 11, 335–340 (2008).

  62. 62.

    Laatikainen, T. et al. Sodium in the Finnish diet: 20-year trends in urinary sodium excretion among the adult population. Eur. J. Clin. Nutr. 60, 965–970 (2006).

  63. 63.

    He, F. J., Brinsden, H. C. & MacGregor, G. A. Salt reduction in the United Kingdom: a successful experiment in public health. J. Hum. Hypertens. 28, 345–352 (2014).

  64. 64.

    Department of Health. Assessment of Dietary Sodium Levels Among Adults (aged 19–64) in England 2011. UK Government Web Archive http://transparency.dh.gov.uk/2012/06/21/sodium-levels-among-adults/ (2012).

  65. 65.

    Polonia, J. & Martins, L. Analysis of some recent data that could explain the reduction of stroke mortality in Portugal during the 2003–2011 interval. J. Hypertens. 32, e75 (2014).

  66. 66.

    DiNicolantonio, J. J., Di Pasquale, P., Taylor, R.S. & Hackam, D. G. Retraction. Low sodium versus normal sodium diets in systolic heart failure: systematic review and meta-analysis. Heart 99, 820 (2013).

  67. 67.

    Adler, A. J. et al. Reduced dietary salt for the prevention of cardiovascular disease. Cochrane Database Syst. Rev. 7, CD009217 (2014).

  68. 68.

    James, W. P., Ralph, A. & Sanchez-Castillo, C. P. The dominance of salt in manufactured food in the sodium intake of affluent societies. Lancet 1, 426–429 (1987).

  69. 69.

    Brinsden, H. C., He, F. J., Jenner, K. H. & MacGregor, G. A. Surveys of the salt content in UK bread: progress made and further reductions possible. BMJ Open 3, e002936 (2013).

  70. 70.

    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 6, 3274–3287 (2014).

  71. 71.

    Barberio, A. M. et al. Population-level interventions in government jurisdictions for dietary sodium reduction: a Cochrane Review. Int. J. Epidemiol. 46, 1551–1405 (2017).

  72. 72.

    Trieu, K. et al. Salt reduction initiatives around the world — a systematic review of progress towards the global target. PLoS ONE 10, e0130247 (2015).

  73. 73.

    U.S. Food & Drug Administration. Sodium reduction http://www.fda.gov/Food/IngredientsPackagingLabeling/FoodAdditivesIngredients/ucm253316.htm (2018).

  74. 74.

    He, F. J. et al. School based education programme to reduce salt intake in children and their families (School-EduSalt): cluster randomised controlled trial. BMJ 350, h770 (2015).

  75. 75.

    Chang, H. Y. et al. Effect of potassium-enriched salt on cardiovascular mortality and medical expenses of elderly men. Am. J. Clin. Nutr. 83, 1289–1296 (2006).

  76. 76.

    He, F. J., Markandu, N. D., Sagnella, G. A. & MacGregor, G. A. Effect of salt intake on renal excretion of water in humans. Hypertension 38, 317–320 (2001).

  77. 77.

    He, F. J., Marrero, N. M. & MacGregor, G. A. Salt intake is related to soft drink consumption in children and adolescents: a link to obesity? Hypertension 51, 629–634 (2008).

  78. 78.

    D’Elia, L., Rossi, G., Ippolito, R., Cappuccio, F. P. & Strazzullo, P. Habitual salt intake and risk of gastric cancer: a meta-analysis of prospective studies. Clin. Nutr. 31, 489–498 (2012).

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Affiliations

  1. Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK

    • Feng J. He
    •  & Graham A. MacGregor

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Contributions

F.J.H. researched data for the article, and both authors discussed the content of the manuscript. F.J.H. wrote the article, and both authors reviewed and edited it before submission.

Competing interests

F.J.H. is a member of Consensus Action on Salt & Health (CASH) and World Action on Salt & Health (WASH). Both CASH and WASH are non-profit charitable organizations, and F.J.H. does not receive any financial support from CASH or WASH. G.A.M. is Chairman of Blood Pressure UK (BPUK), Chairman of CASH, and Chairman of WASH. BPUK, CASH, and WASH are non-profit charitable organizations, and G.A.M. does not receive any financial support from any of these organizations.

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Correspondence to Feng J. He.

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https://doi.org/10.1038/s41569-018-0004-1

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