Better Nutrition (1989-90),  Jan, 1990  by Frank Murray

Potassium Can Lower Blood Pressure

A high intake of dietary potassium, including an extra serving of potassium-rich foods each day, might reduce the risk of death by stroke by up to 40 percent, according to research reported in Medical Tribune.

The 12-year study involved 589 men and women in an affluent community in Rancho Bernardo, Calif., near San Diego. Participants ranged in age from 50 to 79 and there was no history of heart attack or stroke at the time the study began.

The study, headed by Dr. Kay-Tee Khaw, Professor of Clinical Gerontology at Cambridge University, England, was corroborated by animal studies at the University of Minneapolis, Minn., and Cornell Medical College, New York.

Results from the study showed that potassium intake during a 24-hour period ranged from 664.7 milligrams to 6,021.7 mg, with an average of 2,502 mg.

"The protective relationship offered by dietary potassium intake is consistent for both men and women, and it is independent of dietary fiber and other cardiovascular factors," said Dr. Khaw.

Although data from her study as well as other studies abroad suggested that potassium intake worked equally well with both the elderly and the young, Dr. Khaw believes that the mineral might be more effective for the elderly, because these patients are usually more susceptible to the effects of sodium, which would be regulated by the potassium intake. Another study, evaluated by Dr. Khaw and Dr. Elizabeth Barrett-Connor at the University of California, San Diego, found that the relationship between sodium and potassium intakes often determines whether or not a person will develop high blood pressure.

For many years doctors thought that low sodium intake corresponded with low blood pressure. A number of new studies, however, have determined that an increase in potassium intake is also a key factor.

In Dr. Atkins' Health Revolution, Robert C. Atkins, M.D., wrote that regarding hypertension, potassium parallels the magnesium effect and that potassium's competitor at the cell membrane level is sodium.

"Sodium is thought to be one of the villains in hypertension and many studies bear that out," said Dr. Atkins. "It should come as no surprise that potassium supplementation lowers the blood pressure. The first study was done on normal subjects. Soon, I presume, researchers will begin to find potassium useful in hypertensives. At the Atkins Center, we have known this for some time."