Potassium and health

Abstract

Potassium was identified as a shortfall nutrient by the Dietary Guidelines for Americans 2010 Advisory Committee. The committee concluded that there was a moderate body of evidence of the association between potassium intake and blood pressure reduction in adults, which in turn influences the risk of stroke and coronary heart disease. Evidence is also accumulating of the protective effect of adequate dietary potassium on age-related bone loss and reduction of kidney stones. These benefits depend on organic anions associated with potassium as occurs in foods such as fruits and vegetables, in contrast to similar blood pressure-lowering benefits of potassium chloride. Benefits to blood pressure and bone health may occur at levels below current recommendations for potassium intake, especially from diet, but dose-response trials are needed to confirm this. Nevertheless, intakes considerably above current levels are needed for optimal health, and studies evaluating small increases in fruit and vegetable intake on bone and heart outcomes for short periods have had disappointing results. In modern societies, Western diets have led to a decrease in potassium intake with reduced consumption of fruits and vegetables with a concomitant increase in sodium consumption through increased consumption of processed foods. Consumption of white vegetables is associated with decreased risk of stroke, possibly related to their high potassium content. Potatoes are the highest source of dietary potassium, but the addition of salt should be limited. Low potassium-to-sodium intake ratios are more strongly related to cardiovascular disease risk than either nutrient alone. This relationship deserves further attention for multiple target tissue endpoints.

Figure 1

Overview of meta-analyses of studies investigating the mean blood pressure–lowering effects of potassium. DBP, diastolic blood pressure; SBP, systolic blood pressure. Reproduced from reference with permission.

Figure 2

Effect of potassium citrate supplementation after 6 mo in older men and women on net renal acid excretion and calcium retention. Values are mean ± SE; N = 52. Data from reference .

Figure 3

Potassium intake and adjusted risk of stroke among 43,738 U.S. men aged 40–75 y followed for 8 y. Risk was adjusted for age, total energy intake, smoking, alcohol consumption, history of hypertension, history of hypercholesterolemia, parental history of myocardial infarction before age 65 y, profession, and quintiles of BMI, and physical activity. Reproduced from reference with permission.

Figure 4

Potassium citrate at all levels significantly (P < 0.001) decreased mean 10-d cumulative titratable acidity without affecting bone calcium retention (measured by urinary appearance of a bone tracer) in rats (N = 5). Data from reference .