In the dietary battle against high blood pressure, sodium restriction gets the glory but potassium is the unsung hero. It helps rid the body of sodium and protects cells that line blood-vessel walls. In fact, the DASH diet (Dietary Approaches to Stop Hypertension) works not just by minimizing sodium but also by emphasizing fruits, vegetables, and low-fat dairy foods, all of which are good sources of potassium. In addition to blunting the effects of sodium, a potassium-rich diet is also associated with a reduced risk of bone loss, kidney stones, strokes, and type 2 diabetes.
Unfortunately, nearly all Americans consume too much sodium and far too little potassium. "There's a mismatch between what our biological systems are designed for and what we try to make them handle," says R. Curtis Morris, Jr., M.D., a professor of medicine at the University of California, San Francisco.
A September 2010 study suggests what might happen if people corrected the sodium-potassium ratio. It found that even if sodium consumption stayed high, increasing potassium to the recommended levels (4,700 milligrams a day) could reduce the risk of heart-disease mortality by up to 11 percent and stroke mortality by up to 15 percent.
So is it enough to simply take potassium supplements or use salt substitutes made with the mineral? Probably not. "Those are different forms of potassium and likely will not provide the same benefit as the form found naturally in foods," says Morris, a member of a panel convened by the Institute of Medicine to establish potassium recommendations.
Too much potassium is not a problem for most people, but certain conditions and drugs can interfere with the body's ability to get rid of the excess. So talk with a doctor before increasing your potassium intake, even from food, if you have a disorder that causes potassium retention, such as diabetes, heart failure, or kidney disease. Also seek a doctor's opinion if you take ACE inhibitors, such as lisinopril (Prinivil and generic) and ramipril (Altace and generic); angiotensin receptor blockers (ARBs), such as losartan (Cozaar and generic) and valsartan (Diovan); and potassium-sparing diuretics, such as spironolactone (Aldactone and generic).
|Good dietary sources of potassium||Amount (mg)|
|Potato, baked: With skin (1 medium)||925|
|Avocado (½ cup)||585|
|Yogurt: Plain, low-fat (8 oz.)||575|
|Beans, boiled: Black, lentils, lima, kidney, pinto (½ cup)||305 to 485|
|Greens, cooked: Spinach, Swiss chard (½ cup)||420 to 480|
|Orange juice (8 oz.)||475|
|Squash: Winter (½ cup)||450|
|Artichoke (1 medium)||425|
|Banana (1 medium)||420|
|Milk: Skim (8 oz.)||410|
|Recommended daily intake|
|Men and women: 4,700 mg.|
|No upper limit.|