Queen's Neurologist Authors Potassium Study; Implications for Stroke Discovered

Deborah Green, MD.

People with a low amount of potassium in their diet may have an increased risk of stroke, according to a study published in the August 13 issue of Neurology, the scientific journal of the American Academy of Neurology. The study's author is neurologist Deborah M. Green, MD, of the Neuroscience Institute at The Queen's Medical Center.

The study involved 5,600 people over age 65 who were free of stroke when they started the study and were followed for four to eight years. Participants with the lowest amounts of potassium in their diets were 1.5 times more likely to have a stroke than those with the highest amounts. Low potassium intake was defined as less than 2.4 grams per day; high intake was over 4 grams per day. Good sources of potassium include avocados, bananas, citrus fruits, green leafy vegetables, milk and nuts. However, researchers say more studies are needed to determine whether increasing potassium in the diet can prevent strokes.

The study also looked at people who take diuretics, medications used to reduce water in the body but which can decrease potassium. Diuretics are used to treat conditions such as high blood pressure, congestive heart failure and kidney disease. "Diuretics clearly help prevent stroke by controlling high blood pressure, but we wanted to see whether their effect on potassium levels would affect the risk of stroke," said Dr. Green. Of people taking diuretics, the study found that those with the lowest levels of potassium in their blood were 2.5 times more likely to have a stroke than those with the highest levels. Dr. Green stressed that the results do not suggest that diuretics cause a risk of stroke. "The question is whether diuretics would be even more effective with adequate potassium intake," she said.