In the largest meta-analysis ever conducted regarding the effect of potassium on cardiovascular health, researchers found that those who consumed the most potassium reduced their risk of stroke by 21 percent, and reduced their risk of cardiovascular disease as well.

Eleven studies that included a total of nearly 250,000 men and women from six countries were examined, and the information from those studies about the association between potassium intake and stroke, coronary heart disease, and overall cardiovascular disease was analyzed.

The only people who should not increase their potassium intake without speaking to their physician are those with kidney failure or those taking medications that lower potassium.

The Italian researchers concluded that the protective effect of potassium is in part due to its ability to lower blood pressure, especially in hypertensive people and those with a high sodium intake. It may counteract, to some extent, the effects of eating too much salt. Potassium may also be involved in protecting blood vessels from oxidative damage, slowing down the process of atherosclerosis, and preventing thickening of the arteries.

Lead researcher, Dr. Pasquale Strazzulo, said that the average potassium intake in most countries is much lower than what is recommended by health experts. The effect of increasing the intake of dietary potassium by 1.64 grams per day is similar to the risk reduction from lowering dietary sodium intake by 5 grams per day and translates into 1.1 million fewer stroke deaths per year worldwide, according to the researchers.

Dr. Strazzulo, a professor of medicine at the Federico II University of Naples Medical School, in Italy, also noted that most doctors are not aware of the benefits of increasing the intake of potassium-rich foods. Patients with hypertension and those at risk for stroke and other cardiovascular events are often encouraged to reduce their sodium consumption, but tend not to be educated about increasing their potassium intake.

Potassium is found in abundance in fruits and vegetables, particularly bananas, apricots, dates, oranges, potatoes, avocado, and greens. Fish, poultry, and low-fat dairy products also add potassium to the diet.

Virtually all guidelines for healthy eating and disease prevention recommend eating more fruits and vegetables. Patients may need dietary instruction on the specifics of a high potassium diet and how to fit high potassium foods into their personal eating habits and lifestyle, and this advice can best be provided by a registered dietitian. The only people who should not increase their potassium intake without speaking to their physician are those with kidney failure or those taking medications that lower potassium.

The DASH diet is the best example of an eating plan that provides plenty of potassium. It is rich in fruits and vegetables and low in sodium while providing ample amounts of dairy foods, lean meats, and other protein foods. This diet has been tested in various studies and its positive effect on blood pressure has been documented.

The study was published in the March 8, 2011 issue of the Journal of the American College of Cardiology.