Dietary, total body, and intracellular potassium-to-sodium ratios and their influence on cancer.

One of the greatest changes in the human diet, a change that has occurred only within the past few thousand years, is the immense increase in the intake of sodium (Na) caused by use of table salt in the preparation and preservation of food. At the same time, man's intake of potassium (K) has decreased. The result is that from Paleolithic times to modern times the dietary K/Na ratio has been reduced by a factor of about 20. Based on a comparison of modern people in civilized areas with the primitive Yanomamo Indians in South America (who do not eat salt but who do grow and eat potassium-rich cooking bananas), this factor may even be on the order of 100 to 200. Humans, who initially had to adapt to retain sodium from a sodium-poor diet and to excrete potassium from a potassium-rich diet, have not yet evolutionarily adapted to today's high-sodium, low-potassium diet. This failure has caused increased rates of a number of diseases in civilized man, among them cancer. The influence of the K/Na ratio on cancer development--first discovered by epidemiologic studies--has been confirmed by various means, such as dietary studies, gerontological studies, studies of relationships between hyper- and hypokalemic diseases and cancer, and review of the cellular changes of this ratio induced by carcinogenic and anticarcinogenic agents. Recently, animal experiments have also confirmed the results. The recommended dietary K/Na ratio should be well above 1, preferably 5 or higher, and the cellular K/Na ratio should be above 10.