Blood pressure is the force of blood against the walls of the arteries as the heart pumps blood through the body. Hypertension occurs when the force of the blood flow becomes high, which can be attributed to factors such as family history, cholesterol or plaque buildup in the arteries, poor diet or a combination of several factors. Studies have shown that low sodium intake, as part of a healthy, balanced diet, can reduce blood pressure. Adequate potassium intake has also been shown to be beneficial in treating hypertension.
Blood Pressure and Hypertension
Blood pressure measurements are equal to the systolic pressure over the diastolic pressure, with a normal blood pressure reading equal to 120 mm of hemoglobin over 80 mm of hemoglobin. Systolic pressure is the pressure in the arteries when the heart beats, while the diastolic pressure measures the pressure in the arteries between heartbeats. Hypertension, or high blood pressure, is typically any blood pressure reading at or above 140 mm of hemoglobin over 90 mm of hemoglobin.
Role of Potassium
Potassium aids in blunting some of the effects of excessive sodium intake by causing the kidney to excrete sodium from the body. By reducing sodium levels in the body, blood pressure is lowered, since excessive sodium contributes to fluid retention, which can place pressure on the blood vessels. That in turn increases risk of cardiovascular problems.
Potassium Benefits
According to an article published in the December 2010 issue of the "European Journal of Clinical Nutrition," a study over the course of about four years showed a decrease in the development of hypertension in those individuals with high potassium intakes of about 1650 to 1850 mg of potassium per 1000 calories consumed. In addition, those at lower risk for development of hypertension exhibited a higher consumption of fruits and vegetables.
Recommendations
According to the American Heart Association, most individuals should strive to consume 4700 mg of potassium each day. The only exception to this recommendation would be older adults or those with kidney disease, since these individuals may have trouble excreting excess potassium from the body, which can lead to hyperkalemia and potential cardiac arrhythmia.
Dietary Potassium
Increasing daily potassium intake can be as easy as adding more fruits and vegetables to the diet. The American Dietetic Association gives the potassium content of some potassium-rich foods: 496 mg for 1 cup of orange juice, 422 mg for one medium banana, 542 mg for a medium sweet potato with the skin, and 738 mg for a small baked potato with the skin, 420 mg for 1/2 cup cooked spinach, 598 mg for 1/2 cup of raisins, and 448 mg for 1/2 cup of acorn squash, 417 mg for 6 oz. of tomato juice and 528 mg. for 6 oz. of prune juice. In addition, potassium is found in high amounts in some protein-rich foods such as dairy products, fish, and beans. For example, 1/2 cup of kidney or lima beans contains around 400 mg of potassium, 3 oz. of fish such as cod or halibut contains about 450 mg and 1 cup of skim or soy milk contains about 380 mg. Other potassium-rich foods include yogurt, tomato products, dried fruits such as apricots or prunes, and some nuts and seeds such as almonds or sunflower seeds.
References
- MedLine Plus: Blood Pressure
- European Journal of Clinical Nutrition; Role of physical activity and diet in incidence of hypertension: a population-based study in Portuguese adults; Camões, M., Oliveira, A., Pereira, M., Severo, M., and Lopes, C.; December 2010
- American Heart Association: Understanding Blood Pressure Readings
- American Heart Association: Potassium and High Blood Pressure
- Linus Pauling Institute: Potassium
- American Dietetic Association: Potassium Power!
