Potassium potential for stroke prevention endorsed
MedWire News: About one in every five strokes might be prevented if people consumed more dietary potassium, show meta-analysis findings.
"This risk reduction would be translated into a reduction of as many as 1,155,000 stroke deaths per year on a worldwide scale and is expected to produce overall health benefits by reducing the impact of disability to an extent similar to that obtained by dietary salt reduction," say the researchers.
Pasquale Strazzullo ("Federico II" University of Naples Medical School, Italy) and colleagues included 247,510 people from 15 cohorts in their analysis. Follow-up ranged from 5 to 19 years, during which there were 7066 strokes, 3058 coronary heart disease (CHD) events, and 2497 cardiovascular disease events (stroke and CHD not distinguished).
The studies assessed potassium intake by a variety of methods: 24-hour dietary recall, food frequency questionnaire, or 24-hour urinary excretion.
Overall, each 1.64-g increase in daily potassium intake was associated with a 21% reduction in the risk for stroke, the researchers report in the Journal of the American College of Cardiology.
There were also nonsignificant trends toward reduced risks for CHD and CVD with increasing potassium intake. These were based on fewer studies than the stroke endpoint analysis. Exclusion of a single study identified by sensitivity analysis resulted in a statistically significant 7% reduction in CHD risk and a 26% reduction in CVD risk per 1.64-g increase in daily potassium consumption.
"The protective effect of potassium against the risk of stroke may conceivably relate to its blood pressure-lowering effect, particularly in hypertensive individuals and in those with elevated sodium intake," say Strazzullo et al.
However, potassium remained protective against stroke, despite most included studies adjusting for blood pressure and hypertensive status. The team therefore suggests that potassium could have additional beneficial effects, such the anti-oxidative effects reported by previous laboratory studies.
Finally, the researchers note that fruit and vegetables are the primary dietary sources of potassium.
"Thus, the present meta-analysis points to potassium as one of the factors responsible for the beneficial effect of high vegetable and fruit consumption, at least for ischemic stroke," they conclude.
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By Eleanor McDermid