Dietary potassium and hypertension: epidemiologic data.

The strong geographic and social class differences in blood pressure may be related to differences in potassium intake or in the ratio of sodium to potassium intake. "Low salt" populations also have high potassium intake. In Japanese villages, populations with similar salt intake but different blood pressures had different potassium intake. In one study, a significant correlation was found between urinary Na/K ratio and blood pressure. Another study showed a significant negative correlation between potassium excretion and blood pressure. Four studies are available that show that blacks excrete much less potassium than whites. One of these studies also showed, by analyzing duplicate meals, that blacks consumed much less potassium than whites. A high potassium diet tends to be more expensive than a low potassium diet. Potassium intake may be a major factor in the epidemiologic differences of hypertension.