By Steve P Smith
Potassium is one of the most important minerals for human health, playing an essential role in maintaining the correct electro-chemical balance in cells and the proper functioning of cell membranes. This role makes potassium vital for muscle contraction (including the heart muscle), the transmission of nerve impulses, the regulation of blood sugar levels and the synthesis of vital proteins and acids. The maintenance of proper potassium levels within cells, particularly in relation to the corresponding levels of sodium, is consequently crucial for the well-being of the organism.
Clinical potassium deficiency (hypokalemia) is therefore a serious and even potentially fatal medical problem. Fortunately it is hardly ever seen in the generally healthy population, but has been encountered in alcoholics, anorexics and bulimics, those taking certain types of diuretic drug, those suffering from illnesses causing vomiting or diarrhea, and, believe it or not, those given to consuming large quantities of licorice.
But although outright hypokalemia is thankfully very rare, there’s evidence that many people obtain insufficient dietary potassium for optimum health; and that this insufficiency may expose them to an increased risk of chronic diseases, including hypertension (high blood pressure), heart disease, osteoarthritis and even cancer.
Ample evidence of the importance of potassium is provided by the fact that around a third of the body’s at rest energy expenditure is used in maintaing the potassium/ sodium balance in cells Most people are now familiar with idea that a high sodium (salt) intake is one of the main risk factors for the development of high blood pressure, a serious condition if left untreated, but known as the ‘silent killer’ because of lack of obvious symptoms.
Many nutritionists now believe, however, that it is not so much high sodium, but low potassium which may be the real culprit and a substantial body of research evidence supports the idea that a diet rich in potassium will indeed help prevent high blood pressure. The importance of this should not be underestimated, as high blood pressure is strongly associated with an increased risk of stroke – still one of the biggest killers in the West.
It almost goes without saying the that profile of the modern Western diet is far from helpful in this regard. A diet high in processed foods is one likely also to be very high in sodium; and a relatively low consumption of fresh fruits and vegetables is also likely to mean a relatively low intake of dietary potassium. It follows, therefore, that the proportion of sodium to potassium consumed by the typical modern Westerner is almost certainly far higher than ever before in human history; and it is not unreasonable to suppose that that this new imbalance may be a causative factor in some of the degenerative ‘diseases of affluence’, sadly so characteristic of modern urban societies.
By far the best way to ensure an adequate intake of dietary potassium is to consume a diet rich in fresh fruit and vegetables; particularly good sources being bananas and potatoes (in their jackets). Fresh fruit juices, including tomato and orange, also provide a good supply, as do green vegetables such as spinach and dried fruits such as raisins. Soil depletion, however, means that even these foods are poorer in minerals, potassium included, than they used to be; and research suggests that most adults eating a typical Western diet obtain only around 2,000- 3,000 mg of potassium a day.
This figure needs to be set against the adequate intake established by the US Institute of Medicine Food and Nutrition Board of 4,700 mg. And it should also be noted that for those consuming a typical modern diet, high in refined and processed foods, the potassium requirement will be even higher because of the very high sodium content of such a diet. For athletes, and those undertaking strenuous physical work, or intensive exercise programmes, the requirements may be still higher because of greater losses of potassium from the body during these activities.
Nevertheless, nutritional therapists do not generally recommend commercially available potassium supplements, as these normally contain quantities too low to be effective. But high dose supplements are in any case potentially dangerous, as they may have profound effects on the body’s biochemical balance, and should therefore not be taken except under medical supervision. Where the diet is inadequate in potassium, however, this may be simply remedied by using as a food seasoning a low sodium/high potassium salt substitute available from any good supermarket.
As always, however, the body’s holistic functioning means that potassium works best in the presence of a good supply of every other vital nutrient and so it is always worth taking a good quality and comprehensive multi-vitamin/multi-vitamin preparation.
About the Author: Steve Smith is a freelance copywriter specialising in direct marketing and with a particular interest in health products. Find out more at