By: Radha McLean
People in Western countries don’t ingest enough potassium, claim researchers from the United Kingdom. Increasing potassium intake by eating more fruits and vegetables may have a range of health benefits, including lowering blood pressure; reducing the risk of stroke, heart disease and kidney damage; and helping to prevent calcium deficiency and glucose intolerance, these researchers say.
Dr. J. He Feng, research fellow at St. George’s Hospital Medical School in London, England, and a colleague conducted a clinical review of 35 studies, spanning 40 years, on the benefits of potassium. The review was published in the September 1, 2001, issue of the British Medical Journal.
Multiple studies cited in the review have shown that increased potassium intake is associated with a reduction in systolic blood pressure in people with both high and normal blood pressure levels. "The best way to increase potassium intake is to increase consumption of food high in potassium, particularly fresh fruits and vegetables," the researchers write.
They add that higher-than-normal blood pressure is the main risk factor for stroke, and they cite several studies indicating that "high potassium intake caused a large reduction in deaths from stroke."
What’s more, two additional studies note that high potassium intake has also been shown to protect against high blood pressure and kidney disease.
It is also worth noting that consuming high amounts of potassium seems to decrease the amount of calcium excreted in the urine, which could help to reduce calcium deficiency. The review suggests that prevention of osteoporosis may be a long-term benefit.
Potassium deficiency has been linked to glucose intolerance in several studies. In a six-year study of 84,380 women in the United States, reported in the May 1992 issue of the American Journal of Clinical Nutrition, high potassium intake was associated with lower risk of developing type 2 diabetes.
Researchers also explored the possibility that too much potassium could be harmful. They note that high serum potassium concentrations are uncommon except in the case of kidney failure, when the body does not process potassium normally.
Eating processed foods, from which potassium has been removed, in combination with eating fewer fruits and vegetables, has contributed to a diet low in potassium, the researchers conclude.
Currently, the average consumption of potassium in Western countries is 2.7 grams a day. A diet considered high in potassium contains up to 7.8 grams a day, according to the review.
Clinical Adviser’s note: A good thing for some can be dangerous for others. People with impaired kidney function may not be able to clear potassium from the body normally. Dangerous—even fatal—blood levels of potassium may result. For this same reason, people with impaired kidney function may not be able to continue to take ACE inhibitors, a class of blood pressure and kidney protective medications that may promote potassium retention in people with impaired kidney function. Check with your physician before increasing potassium intake if you are unsure of the status of your kidney function.
Remember that salt substitute is high in potassium.