Sodium and potassium both affect blood pressure. Sodium raises blood pressure, while potassium lowers blood pressure and lessens the adverse effects of sodium on blood pressure. On average, Americans consume twice the recommended amount of sodium, but only half the recommended amount of potassium. To lower your blood pressure, reduce your sodium intake to no more than 1,500 mg daily, and increase potassium intake to 4,700 mg daily or more.
Sodium and Blood Pressure
High sodium intake, especially with inadequate potassium intake, raises blood pressure. Your body needs only a small amount of sodium. When you consume too much sodium, your body retains water to dilute the sodium. This extra fluid puts stress on the heart and blood vessels. Over time, this can lead to high blood pressure, heart attack, stroke and heart failure. Too much salt can cause damage in the body, even if your blood pressure is normal.
Potassium and Blood Pressure
Inadequate potassium intake also raises blood pressure. According to the 2010 Dietary Guidelines Advisory Committee report, 97 percent of Americans do not meet recommended intake levels. Potassium has been identified as one of four underconsumed nutrients of public concern in the U.S. Eating more potassium-rich foods can lower your blood pressure by relaxing blood vessels and by blunting the adverse effects of sodium. It may also prevent stroke and coronary heart disease.
Potassium Sources
Every food group has high potassium foods. Look for potassium-rich fruits, such as prune, orange or grapefruit juice, bananas, cantaloupe, honeydew, mango or dried peaches, apricots or prunes. White or sweet potatoes with skin, carrot juice, tomato products, beets, legumes, soybeans, spinach, collard, turnip and beet greens, winter squash, pumpkin, Brussels sprouts, peas, corn parsnips and carrots are good vegetable sources. Plain yogurt, low-fat milk, clams, halibut, yellowfin tuna, rockfish, cod, rainbow trout and pork loin are also good sources.
DASH Trials
The DASH Trials -- for Dietary Approaches to Stop Hypertension -- showed that eating a diet high in potassium-rich fruits and vegetables could lower blood pressure. Even further reduction in blood pressure was seen in those who followed DASH guidelines and limited sodium intake to either 2,300 mg or 1,500 mg daily. The greater the sodium reduction, the greater the improvement in blood pressure. So, while potassium can help counteract sodium to lower blood pressure, you can see the greatest improvement in your blood pressure if you both increase potassium and decrease sodium intake.
References
- Harvard School of Public Health: Lower Salt and Sodium: A Key to Good Health
- Cleveland Clinic; High Blood Pressure and Nutrition; October 2010
- Dietary Guidelines Advisory Committee; Sodium, Potassium, and Water; June 15 2010
- Dietary Guidelines Advisory Committee; Nutrient Adequacy; June 15 2010
- Harvard School of Public Health: Salt and Heart Disease: Key Studies
