Potassium, sodium, and chloride, are called electrolyte minerals, because they conduct electricity when dissolved in water. These minerals work together closely. About 95% of the potassium in your body is stored within your cells, while sodium and chloride are predominantly located outside your cells. Potassium helps:

• Regulate muscle contraction, including heart rythym
  
• Regulate nerve transmission, including in your brain and central nervous system
• Store carbohydrates for your muscles to use as fuel, and promote regular muscle growth
• Maintain your body’s proper electrolyte and acid-base (pH) balance
• Lowers blood pressure by counteracting the detrimental effects of sodium and regulating fluid balance
• Maintain the density and strength of your bones by decreasing urinary calcium loss caused by the high-salt diets typical of most Americans

Humans evolved from simple unicellular organisms in the mineral-laden ocean. Now, billions of years later, the saline fluids around and in your cells and organs recreates that environment, with a similar balance of minerals. Sodium, along with potassium, provides the electrolytic “battery” that pumps nutrients in and out of cells and maintains the proper balance of fluids inside and outside each cell. Because sodium is not easily found in the land environment, your body evolved to retain it. Potassium, on the other hand, is plentiful in a land-based diet (in vegetables, nuts, seeds, and fruits) and so we do not retain potassium. The modern industrialized diet reverses the natural availability of sodium and potassium: potassium is leached out of processed foods, and sodium is used extravagantly as a flavor enhancer and preservative. In addition, the modern diet often lacks magnesium and calcium, and manufactured table salt is exclusively sodium chloride.

Potassium in the correct amount is especially important in regulating the frequency and degree to which your muscles contract, and the degree to which your nerves become excitable. Many of your muscle and nerve cells have specialized channels for moving potassium in and out of the cell. Sometimes potassium moves freely in and out, and sometimes, it uses the “sodium-potassium pump.” Most of the potassium in your body is stored inside of your cells, while most of the sodium in your body is stored in the fluid that surrounds your cells. During muscle contraction and nerve transmission, potassium leaves the cell and sodium enters the cell via the “sodium-potassium pump.” This transfer causes a change in electrical charge within the cell, which initiates the muscle contraction or the nerve impulse. Because sodium attracts water, once the muscle contraction or nerve impulse is initiated, the sodium is immediately pumped out of the cell to prevent water from entering the cell and causing the cell to swell or burst, and potassium is pumped back into the cell. When the movement of potassium is blocked, or when potassium is deficient in your diet, the activity of both muscles and nerves can become compromised.

If you experience excessive fluid loss, through vomiting, diarrhea, overuse of diuretics (including caffeinated beverages), poor water intake, a low-carbohydrate diet, or sweating, or if you take certain medications, you may be at risk for potassium deficiency. In addition, a diet that is high in sodium and low in potassium can negatively affect potassium status. The Standard American Diet (SAD), which is high in sodium-containing processed foods and low in fruits and vegetables, contains about two times more sodium than potassium. Many health experts recommend taking in at least five times more potassium than sodium. The symptoms of potassium deficiency include muscle weakness, confusion, irritability, fatigue, and heart disturbances. Athletes with low potassium stores may tire more easily during exercise, as potassium deficiency causes a decrease in glycogen (the fuel used by exercising muscles) storage. In addition to poor dietary intake, excessive physical activity can increase your need for potassium. People with high blood pressure also need more potassium.

Elevated blood levels of potassium can be toxic, and may cause an irregular heartbeat or even heart attack. Under most circumstances, your body maintains blood levels of potassium within a tight range, so it is not usually possible to produce symptoms of toxicity through intake of potassium-containing foods. However, high intakes of potassium salts (potassium chloride and potassium bicarbonate) may cause nausea, vomiting, diarrhea, and ulcers. In addition, certain medications can cause elevated potassium levels. Your kidneys play an important role in eliminating excess potassium from the body, so if you suffer from kidney disease, your doctor may have you limit your intake of potassium. The National Academy of Sciences has not established a Tolerable Upper Intake Level (UL) for potassium.

Potassium can leech out of food when it is cooked in water. In the case of spinach, for example, potassium levels drop 56% after blanching for several minutes. Consuming vegetable soups means that you retain all the nutrients that leach into the cooking broth. In the same way, parsley tea often contains significant amounts of potassium because this mineral is leached out of the parsley leaves and into the hot tea water.

You can find abundant potassium in fruits and vegetables. Excellent sources of potassium include chard, lima beans, potatoes, yams, soybeans, and spinach. Very good sources of potassium include papaya, pinto beans, lentils, kidney beans, dried peas, avocado, dulse, sweet potato, winter squash, beets, cantaloupe, tomatoes, bananas, carrots, crimini mushrooms, green peas, fennel, Brussels sprouts, blackstrap molasses, cauliflower, prunes, kale, summer squash, turnip greens, broccoli, mustard greens, asparagus, shiitake mushrooms, celery, oranges, onions, Romaine lettuce, kiwifruit, and collards. Good sources of potassium include strawberries, green beans, bell peppers, eggplant, raspberries, grapefruit, and grapes.

Foods High in Potassium

This blog uses the latest nutritional data available from the USDA (United States Department of Agriculture), and the FDA (United States Food and Drug Administration), as well as nutritional data provided by food growers and manufacturers about their products. We believe the information on this blog to be accurate. However, we are not responsible for typographical or other errors. Nutrition information for recipes is calculated by Living Cookbook based on the ingredients in each recipe based on statistical averages. Nutrition may vary based on methods of preparation, origin and freshness of ingredients, and other factors.

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