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The Potassium Connection

Not everyone is sensitive to the blood pressure effects of sodium. Most Americans consume more than the recommended amount of salt, yet the majority does not have high blood pressure. This suggests that other factors are also involved in hypertension risk. One culprit, researchers now believe, is lack of potassium.

Potassium deficiency causes cells to take up sodium. That, in turn, causes blood pressure to rise. When volunteers in several studies consumed their usual levels of sodium but cut back on potassium, blood pressure levels jumped by up to 7 points. When they increased their potassium intake, in contrast, blood pressure fell, even when the amount of sodium they consumed remained the same.

In the DASH trial, for example, volunteers who consumed the usual amount of salt -- but added servings of fruits and vegetables with potassium -- saw their blood pressure fall significantly.

Abundant sources of potassium include bananas, raisins, spinach, chard, milk, potatoes baked with the skin, lima beans, and prunes.

What to Look For on the Label

The most perilous combination, experts now say, is a high-salt, low-potassium diet. Unfortunately, that describes the diet that most Americans eat. You can use nutrition facts labels to help you reverse that trend.

The nutrition facts label prominently displays sodium, including both the milligrams contained in a serving and how much of your daily value that amount represents. Foods that have 5% of the daily value or less are considered low in sodium. Those with 20% or more are considered high in sodium.

Keep in mind: the label calculates a daily value of 2,300 mg sodium. The DASH-Sodium study showed that cutting back further than that lowers hypertension risk. The less salt you consume, the more likely your blood pressure will remain out of the danger zone.

As for potassium, one of the simplest ways to get enough is shop in the produce section of your grocery store. Fruits and vegetables are the leading source of this crucial nutrient. Shopping in the produce aisle has another advantage: you don’t have to worry about reading labels.