The American Heart Association recognizes the importance of potassium for blood pressure regulation and normal heart function. Potassium, like some other essential minerals including sodium, magnesium and calcium, functions as an electrolyte in the body, which means that it helps conduct electrical impulses. This role of potassium makes it vital to normal neural function.
Importance of Potassium
Potassium and sodium both carry a positive charge, but approximately 98 percent of the potassium in the body is found in the fluid inside of cells, while the majority of sodium stays in the fluid outside of cells. This concentration difference between sodium and potassium creates an electrochemical gradient known as a membrane potential. In nerve cells, this balance between sodium and potassium generates the electrical potential that conducts the nerve impulses. In muscle cells, the potassium promotes the contraction of the cell and in the heart it helps regulate the heartbeat. Failing to maintain potassium levels can impact the function of nerves and muscles and cause irregular heartbeats.
Potassium Regulation
To maintain normal neural function, your body must maintain the balance between sodium and potassium. Potassium regulation involves several factors including your daily potassium intake, the production of the hormone aldosterone and kidney function. Your adrenal gland produces the hormone aldosterone, which stimulates the kidneys to increase the reabsorption of sodium and water while releasing potassium into the urine. If you fail to intake enough potassium each day or your kidneys filter out too much potassium from the blood, it can lead to a potassium deficiency. Too much potassium in the body, a condition usually caused by a decline in kidney function, can also affect neural function.
Hypokalemia
A potassium deficiency, a condition known as hypokalemia, usually occurs when the kidney releases too much potassium into the urine. Without adequate amounts of potassium in the cells the electrical impulses get interrupted causing symptoms including weakness, muscle cramps and irregular heartbeat.
Hyperkalemia
Hyperkalemia describes a condition characterized by too much potassium in the body. Hyperkalemia can cause irregular heartbeat, or arrhythmia, and lead to a weak or slow pulse. Hyperkalemia requires prompt treatment because the interruption in normal neural function in the heart can lead to the absence of a heartbeat known as cardiac arrest.
Dietary Potassium
The Institute of Medicine recommends all adults intake 4,700 mg of potassium per day. The Linus Pauling Institute reports that on average men only intake 3,200 mg of potassium per day and women only intake 2,300 mg. These averages fall short of the recommendation. To increase your potassium intake consume foods rich in potassium including bananas, potatoes, prunes, orange juice, tomato juice, raisins and spinach. A diet rich in fresh fruits, vegetables and whole grains provides a high intake of potassium and a low intake of sodium.
References
- American Heart Association: Potassium and High Blood Pressure; January 2011
- Periodic Paralysis International: Role of Potassium in Maintaining Health; Haas; 2000
- University of Maryland Medical Center: Potassium; Ehrlich; May 2009
- Linus Pauling Institute: Potassium; Victoria Drake; December 2010
- Institute of Medicine: Dietary Reference Intakes; 2005
Member Comments