Confirming the Association Between Potassium Intake and Stroke Risk

Adequate dietary intake of 3 minerals—potassium, calcium, and magnesium—has been generally associated with reduced stroke risk. More specifically, quality evidence indicates that increased potassium levels improve vascular endothelial function and promote nitric oxide release, thus advancing vascular flow.

A new study published in the October 2014 issue of Stroke examined the effects of dietary potassium on stroke risk in older women. The research confirmed that, regardless of the presence or absence of hypertension—a significant risk factor for stroke—women who consume adequate amounts of potassium have reduced stroke risk.

Using data from the Women’s Health Initiative on 90,137 postmenopausal women aged 50 to 79 years, the study authors prospectively monitored total, ischemic, and hemorrhagic stroke, as well as all-cause mortality, for an average of 11 years. At baseline, all study subjects were stroke-free.

Among the women, the mean self-reported dietary potassium intake was 2611 mg/d. After comparing the subjects across quartiles of potassium intake, the researchers found that those in the highest quartile consumed >3193.6 mg of potassium, while those in the lowest quartile consumed <1925.5 mg.

Women who reported consuming the highest amount of potassium were 12% less likely to experience a stroke and 16% less likely to have an ischemic stroke than those who consumed the lowest amount, the study found. All-cause mortality was also significantly reduced in women in the highest quartile.

The results indicated the relationship between potassium intake and stroke risk was strongest in women who did not have hypertension, as they were 27% less likely to experience stroke if they consumed adequate amounts of potassium. However, the researchers found no association between potassium intake and hemorrhagic stroke.

The US Department of Agriculture advises women to consume ≥4700 mg of potassium daily, which is significantly greater than the mean intake reported in this study. As a result, the authors urged clinicians to reinforce the importance of a potassium-rich diet, especially among postmenopausal women. They noted that diets high in processed meats and low in fruits and vegetables are associated with inadequate potassium levels.