For most people a diet with many high potassium foods has a lot of benefit. It can decrease hypertension, reduce the chance of kidney stones, and help maintain bone density. However, there are some people who require a low potassium diet. They will usually know they have to restrict their potassium because they will be under the care of a doctor. The doctor will tell them of the need for a low potassium diet, and either the doctor or a dietitian will tell them how to stay on one.
Those who have poorly functioning kidneys are the most common group to require a low potassium diet. Those on dialysis almost always are on special diets that have a low amount of potassium. The kidneys are the main regulators of the amount of sodium and potassium in our blood stream, and subsequently in our entire body, including within the cells and in the space between the cells. Sodium and potassium play a major role in the functioning of our cell membranes. To keep the cell membranes functioning properly, the sodium and potassium balance needs to be right. There are portions of the kidney that balance the sodium and potassium excretion and resorption. As the kidney starts to fail, it may be unable to excrete enough potassium. A low potassium diet will improve the sodium and potassium balance in the body.
No need to worry about the balance if you go to a doctor fairly regularly. Most doctors run a common, routine blood test that checks the sodium, potassium and creatinine in your blood stream. The creatinine checks how well the kidney is working. If that test and your blood potassium level are okay, you would probably benefit from a high potassium diet. The body will be able to handle large amounts of potassium. In fact, the Institute of Medicine does not mention an upper limit to the daily recommended allowance for potassium like they do for sodium.
Poorly functioning adrenal glands, also known as Addison's disease, is another condition benefitting from a low potassium diet. One of the hormones inadequately produced by the adrenal glands in Addison's disease is aldosterone, which affects the kidney's handling of sodium and potassium. Less aldosterone means less excretion of potassium.
Another disease with low aldosterone is hyporeninemic hypoaldosteronism. It is a condition in elderly patients in which aldosterone is low, but the other hormones from the adrenal gland are normal. Because of kidney disease, aldosterone and renin (produced by the kidney) are low, resulting in excess potassium in the blood stream.
If you have high blood pressure or congestive heart failure, you may be on a potassium sparing diuretic to prevent excessive fluid retention. Usually this type of diuretic is taken with a diuretic that promotes potassium secretion to balance the potassium in the blood. When you are on a potassium sparing diuretic, you may need to be on a low potassium diet, eating low potassium foods, and should check with your doctor. The potassium sparing diuretics are: amiloride (Midamor), Triamterene (Dyrenium), Spironolactone (Aldactone), and Eplerenone (Inspra).
There are some other rare diseases that also require a low potassium diet. But these patients will know of their need for eating low potassium foods, being under the care of a doctor. If you do not have one of these rare conditions, or one of the not so rare conditions previously mentioned, you will benefit from consuming plenty of high potassium food. The benefits of high potassium foods are better energy, less fatigue, less likelihood of developing hypertension, less chance of kidney stones, and better bone density.