INTAKE OF POTASSIUM, MAGNESIUM, CALCIUM, AND FIBER AND RISK OF STROKEAMONG US MEN

Background-Animal experiments and epidemiological studies have suggest ed that high potassium intake may reduce the risk of stroke, but the e vidence is inconclusive, and the role of other nutrients in potassium- rich foods remains unknown. Methods and Results-We examined the associ ation of potassium and related nutrients with risk of stroke among 43 738 US men, 40 to 75 years old, without diagnosed cardiovascular disea ses or diabetes, who completed a semiquantitative food frequency quest ionnaire in 1986. During 8 years of follow-up, 328 strokes (210 ischem ic, 70 hemorrhagic, 48 unspecified) were documented. The multivariate relative risk of stroke of any type for men in the top fifth of potass ium intake (median intake, 4.3 g/d) versus those in the bottom (median , 2.4 g/d) was 0.62 (95% CI, 0.43, 0.88; P for trend=0.007). Results f or ischemic stroke alone were similar. Intakes of cereal fiber and mag nesium, but not of calcium, were also inversely associated with risk o f total stroke. These inverse associations were all stranger in hypert ensive than normotensive men and were not materially altered by adjust ment for blood pressure levels. Use of potassium supplements was also inversely related to risk of stroke, particularly among men taking diu retics (relative risk, 0.36; 95% CI, 0.18, 0.72). Conclusions-Although these data do not prove a causal relationship, they are consistent wi th the hypothesis that diets rich in potassium, magnesium, and cereal fiber reduce the risk of stroke, particularly among hypertensive men. Potassium supplements may also be beneficial, but because of potential risks, use should be carefully monitored and restricted to men taking potassium-losing diuretics.