The cardiovascular system consists of the heart, the blood vessels and the blood. Many factors affect your cardiovascular system and its ability to work efficiently. Blood pressure -- the measure of the force of blood against the walls of the blood vessels -- is one factor that helps you monitor the health of your cardiovascular system. High blood pressure, defined by the National Heart, Lung and Blood Institute as a consistent systolic pressure of 140 mmHg or higher or a diastolic pressure of 90 mmHg or more, occurs in response to many dietary factors, including the intake of sodium and potassium.
Role of Potassium
Potassium, like sodium, functions as an electrolyte in the body. Electrolytes help balance the amount of fluid in and out of cells and help to carry electrical impulses between the nerves, muscles and brain. This makes potassium vital to all actions in the body that involve muscles, including the functions of the digestive system and the beating of the heart. Because high blood pressure, medically known as hypertension, affects 1 in 3 adults in the United States, it continues to be a focus of research. Recent research by the Harvard Medical School has shown the importance of potassium in regulating blood pressure.
Blood Pressure Regulation
Many factors affect your blood pressure. Consuming large amounts of saturated fat in your diet can increase your blood cholesterol level. This causes cholesterol to build up in your blood vessels, forming plaque, restricting the flow of blood and increasing blood pressure. Sodium, also known as salt, attracts water. Consuming excess amounts of sodium can increase the amount water in the blood. As blood volume increases, the blood pressure must increase to keep the blood pumping through the vessels. Because potassium works closely with sodium, the amount of potassium in your blood also affects your blood pressure.
Potassium and Sodium
Potassium and sodium along with other electrolytes, including calcium and magnesium, work together to keep muscles contracting and the heart beating while also maintaining blood pressure. Therefore, the amount of each one can impact how the other affects the body. The American Heart Association says that potassium can blunt the effects of sodium. This means that maintaining adequate potassium levels can protect against the ability of sodium to cause high blood pressure. Although the exact mechanism of action continues to be studied, the Colorado State University Extension suggests that high potassium levels can increase the amount of sodium excreted from the body.
Effects of Low Potassium
Failing to consume 4,700mg of potassium per day -- the amount recommended by the National Institute of Medicine Food and Nutrition Board -- can lead to hypokalemia, or a low potassium level. The most common symptoms of hypokalemia include weakness, muscle cramps, lack of energy and irregular heartbeat. In addition, as potassium levels fall, the potassium can no longer protect against the effects of too much sodium. Patients with low potassium levels therefore have an increased risk of developing high blood pressure.
References
- National Heart, Lung and Blood Institute: What is High Blood Pressure?
- American Heart Association: Potassium and High Blood Pressure
- University of Maryland Medical Center: Potassium
- Harvard Medical School Family Health Guide: Potassium Lowers Blood Pressure
- Colorado State University Extension: Potassium and Health
- National Institutes of Medicine: Food and Nutrition Board: Dietary Reference Intakes
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