A banana a day could improve blood pressure and heart health for women

SOPHIA ANTIPOLIS, France — Eating more potassium-rich foods like bananas, avocados, and salmon could protect older women against a heart attack or stroke, a new study reveals.

Specifically, researchers say potassium is an essential mineral that lowers blood pressure, especially among people who consume too much salt. A potassium-rich diet can also combat cardiovascular disease, the world’s biggest killer.

“It is well known that high salt consumption is associated with elevated blood pressure and a raised risk of heart attacks and strokes,” says Lead author Professor Liffert Vogt from Amsterdam University Medical Centers in a media release.

“Health advice has focused on limiting salt intake but this is difficult to achieve when our diets include processed foods. Potassium helps the body excrete more sodium in the urine. In our study, dietary potassium was linked with the greatest health gains in women.”

The findings are based a study of nearly 25,000 men and women between 40 and 79 in the United Kingdom, tracked by researchers for roughly two decades. As daily potassium intake increased, blood pressure went down in women with high salt intake.

Every bite of potassium drops blood pressure

Every additional gram of potassium displayed a connection to a 2.4-mm/Hg drop in systolic blood pressure — the force at which the heart beats and the top number in a blood pressure reading. Potassium is also present in other fruits, vegetables, nuts, seeds, milk, fish, beef, chicken, turkey and bread. There was no association with blood pressure among men.

“The results suggest that potassium helps preserve heart health, but that women benefit more than men. The relationship between potassium and cardiovascular events was the same regardless of salt intake, suggesting that potassium has other ways of protecting the heart on top of increasing sodium excretion,” Prof. Vogt says.

Participants were members of the EPIC-Norfolk study, recruited from general practices across the county between 1993 and 1997. They completed a questionnaire on lifestyle habits and also provided scientists with blood pressure and urine samples.

The volunteers were divided into six groups, reflecting low, medium, and high intakes of both potassium and salt. Overall, those with the most potassium in their diet had a 13-percent lower risk of heart attacks or strokes compared to their peers with the least.

“Our findings indicate that a heart healthy diet goes beyond limiting salt to boosting potassium content. Food companies can help by swapping standard sodium-based salt for a potassium salt alternative in processed foods. On top of that, we should all prioritize fresh, unprocessed foods since they are both rich in potassium and low in salt,” the study author continues.

Which foods are the best sources of potassium?

During the study, 13,596 participants (55%) were hospitalized or died due to cardiovascular disease. The Dutch team also took into account age, sex, BMI (body mass index), sodium intake, use of cholesterol lowering drugs, smoking, alcohol intake, diabetes, and prior heart attack or stroke.

The World Health Organization (WHO) recommends adults consume at least 3.5 grams of potassium a day and no more than a teaspoon, less than five grams, of salt. They advise eating lots of vegetables, fruit, nuts, beans, dairy products, and fish. A four-ounce banana has 375 mg of potassium, while five ounces of cooked salmon has 780 mg. A 136-gram potato has 500 mg and half a pint of milk contains 375 mg of the key nutrient.

The study is published in the European Heart Journal.

South West News Service writer Mark Waghorn contributed to this report.

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