More Potassium in Diet Reduces Stroke Risk
Include more foods rich in potassium, like bananas and beans, in your diet and you may reduce your risk of stroke, says a new study. Increased intake of potassium was associated with a lower risk of ischemic stroke, the most common type of stroke.
Potassium is found in many foods
A research team at Karolinska Institute in Stockholm, Sweden, analyzed 10 international studies that involved nearly 270,000 middle-aged and older adults. Among these adults, 8,695 (about 1 in 30) had a stroke.
Overall, they found as people increased their potassium intake by 1,000 mg daily, there was a corresponding decline in the risk of stroke within the next 5 to 14 years of 11 percent. Most of the studies in the meta-analysis had been adjusted for factors such as age, smoking, diabetes, exercise habits, and alcohol use.
The reduction in stroke risk was for ischemic stroke only. An ischemic stroke occurs when the artery to the brain is blocked. About 80 percent of strokes are ischemic. Potassium was not associated with a lower risk of hemorrhagic strokes, which occur when there is bleeding in the brain.
Potassium is a mineral that is essential for nerve and muscle control, regulating blood pressure, and helping to keep the body's fluids in balance. For these latter two tasks, potassium works to maintain a balance with sodium (salt). When people consume too much salt and not enough potassium, blood pressure can rise, which increases the risk of stroke.
Foods rich in potassium include most fruits and vegetables (especially bananas, lima beans, apricots, cantaloupe, baked potatoes, winter squash, raisins, spinach) and beans/legumes. In the United States, the recommended intake of potassium for adults is 4,700 mg daily. This should be balanced with no more than 2,300 mg of sodium, although most people get more salt in their diets, especially from processed and fast foods.
Potassium-rich foods are typically good sources of other nutrients that may help reduce the risk of stroke, such as fiber, magnesium, and vitamin C. However, the authors of the meta-analysis noted that most of the studies had adjusted for other nutrients, and that the benefit from potassium remained.
Larsson S et al. Dietary potassium intake and risk of stroke. Stroke 2011; doi: 10.1161/strokeaha.111.622142
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