Elsevier

Mayo Clinic Proceedings

Volume 88, Issue 9, September 2013, Pages 987-995
Mayo Clinic Proceedings

Review
Role of Dietary Salt and Potassium Intake in Cardiovascular Health and Disease: A Review of the Evidence

https://doi.org/10.1016/j.mayocp.2013.06.005Get rights and content

Abstract

The objective of this review was to provide a synthesis of the evidence on the effect of dietary salt and potassium intake on population blood pressure, cardiovascular disease, and mortality. Dietary guidelines and recommendations are outlined, current controversies regarding the evidence are discussed, and recommendations are made on the basis of the evidence. Designed search strategies were used to search various databases for available studies. Randomized trials of the effect of dietary salt intake reduction or increased potassium intake on blood pressure, target organ damage, cardiovascular disease, and mortality were included. Fifty-two publications from January 1, 1990, to January 31, 2013, were identified for inclusion. Consideration was given to variations in the search terms used and the spelling of terms so that studies were not overlooked, and search terms took the following general form: (dietary salt or dietary sodium or [synonyms]) and (dietary potassium or [synonyms]) and (blood pressure or hypertension or vascular disease or heart disease or chronic kidney disease or stroke or mortality or [synonyms]). Evidence from these studies demonstrates that high salt intake not only increases blood pressure but also plays a role in endothelial dysfunction, cardiovascular structure and function, albuminuria and kidney disease progression, and cardiovascular morbidity and mortality in the general population. Conversely, dietary potassium intake attenuates these effects, showing a linkage to reduction in stroke rates and cardiovascular disease risk. Various subpopulations, such as overweight and obese individuals and aging adults, exhibit greater sensitivity to the effects of reduced salt intake and may gain the most benefits. A diet that includes modest salt restriction while increasing potassium intake serves as a strategy to prevent or control hypertension and decrease cardiovascular morbidity and mortality. Thus, the body of evidence supports population-wide sodium intake reduction and recommended increases in dietary potassium intake as outlined by current guidelines as an essential public health effort to prevent kidney disease, stroke, and cardiovascular disease.

Section snippets

Methods and Evidence Base

Studies in this review include randomized controlled trials (RCTs) linking dietary salt and potassium intakes to subsequent morbidity and mortality, which determine the health outcomes of reducing salt intake and increasing potassium intake by diet or supplementation. The following databases (January 1, 1990, to January 31, 2013) were examined: Cochrane Central Register of Controlled Trials, MEDLINE (Pubmed and Quertle), EMBASE, Cumulative Index to Nursing & Allied Health Literature, Database

Results

From the literature evaluated, 52 studies met the criteria for this review (Table 3 and Supplemental Table [available online at http://www.mayoclinicproceedings.org]). Of these studies, 28 involved modification of dietary salt intake,15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42 12 involved modification of dietary potassium intake,51, 52, 53, 54, 43, 44, 45, 46, 47, 48, 49, 50 and 12 involved modification of both dietary salt and

Discussion

This analysis focused specifically on RCTs. The quality of the evidence of the included studies was then graded using published guidelines. Although many of these RCTs received a grade less than “A,” a sufficient number of studies were graded “A” (Supplemental Table, available online at http://www.mayoclinicproceedings.org), resulting in a level 1 recommendation for salt restriction and potassium supplementation. For some investigators, the relationship between dietary salt intake and health

Implications for Clinicians and the General Public

In the United States, current recommendations and guidelines81, 82 emphasize a reduction in dietary salt intake and a simultaneous increase in dietary potassium consumption. The Institute of Medicine, the American Heart Association, and the US Department of Health and Human Services/US Department of Agriculture recommend limiting salt intake. For potassium, the data suggest that supplementation is best achieved through alterations in the diet. The analyses provided in the present study support

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    Grant Support: Dr Sanders is supported by the Nephrology Research and Training Center at the University of Alabama at Birmingham; the Office of Research and Development, Medical Research Service, Department of Veterans Affairs; a George M. O'Brien Kidney and Urological Research Centers Program (grant P30 DK079337); and NIH grant R01 DK04699.

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