High potassium foods supply an essential mineral — potassium. Everyone needs potassium. Potassium is the main cation (positively charged atom) inside our cells. It is involved in a great many processes in our cells. It helps maintain the membrane potential in all our cells. The membrane potential is the electrical difference between the inside of the cell and the outside, and it helps to drive many of the activities of the cell. The cell membrane that encloses all the parts of the cell maintains and protects the integrity of the cell, like our skin encloses all the parts of our body maintaining and protecting the body.
Potassium is the main ion that allows nerve cells to send their messages throughout the body by turning the membrane potential into an action potential, sending an electrical signal along the nerve. Along with calcium, it is the main ion initiating muscle contraction, allowing us to move. Potassium is also involved with certain cells that produce secretions.
So everyone needs potassium, but why eat high potassium foods? Don't we get enough from just about any food? Although potassium is in many of our foods, it has been estimated that the average American only takes in about half the daily recommended amount of potassium, or about 2 grams. The Institute of Medicine recommends a daily allowance of 4.7 grams. By eating high potassium foods, we can get the recommended amount. There is no upper limit to the amount of potassium that can be consumed by those in good health. Only those with reduced kidney function, Addison's disease, those on potassium sparing diuretics and those with some other rare diseases need to worry about getting too much.
Most of the foods the average American eats are high in sodium and low in potassium. The daily upper intake level for sodium is recommended to be 2.3 grams by the Institute of Medicine. Greater than 95% of men and 75% of women in the U.S. get more than the upper level of sodium. Sodium competes with potassium in many of our bodies' reactions. This results in a balancing act in which the more sodium we take in, the more potassium we need. Far better to have a low sodium diet and eat high potassium foods.