Nutritional deficiencies decrease a person's capacity to resist infection and its consequences and decrease the capability of the immune system. In old age, there is a decrease in skin hypersensitivity reactions, a decreased number of T cells, and impairment of some phagocytic functions. Surveys of the population have discovered nutritional deficiencies in senior citizens that also lead to impairment of the immune system. It is possible that the gradual impairment of the immune system associated with aging may, in fact, be due to one or more nutrient deficiencies. Poor nutrition adversely affects all components of the immune system, including T cell function, other cellular-related killing, the ability of Â cells to make antibodies, the functioning of the complement proteins, and phagocytic function. When several of these functions or processes are impaired, the ability of the entire immune system to keep a watchful eye for cancer cells, abnormal cells, or foreign substances and to dispose of them is also markedly impaired.
Protein deficiency affects all the organs in the body. The number of digestive enzymes produced is reduced, and absorption of nutrients is impaired. With severe chronic protein deficiency the heart muscle atrophies. The immune system is also severely affected. In diets that are only moderately deficient in protein, phagocytes and T cells are reduced in number, and their ability to kill cancer and other abnormal cells is impaired. The amount of antibody is slightly reduced as is the speed with which it attaches to an "enemy." The complement proteins also have impaired function in this state. Hence, a person who is not consuming the proper amount of protein will have a malfunctioning immune system that will not be able to deal effectively with cancer cells or infection.
The immune system is affected by both hypoglycemia (low blood sugar) and hyperglycemia, as in diabetes mellitus. C.J. Van Oss has found that phagocytic function in humans is impaired if the blood sugar level is very low. Much more research has been done concerning the function of the immune system in diabetes. The number of T and Â cells is normal in diabetes, but their functions are impaired: phagocytic function as well as cellular killing. The degree of impairment correlates very well with the fasting blood sugar level and then improves when the sugar level becomes normal.
Lipids have a significant effect on the functioning of the immune system. Cholesterol oleate and ethyl palmitate inhibit antibody production, probably because these lipids do not allow the immune system to recognize the foreign substance. Researchers E.A. Santiago-Delpin and J. Szepsenwol wanted to know what effects lipids had on T lymphocytes. They first grafted pieces of skin from one mouse to another of dissimilar genetic make-up and found that the grafted skin was rejected in a very short time. They then fed the recipient mouse a high-fat diet and found that it accepted the graft for a very prolonged time, indicating that the high-fat diet impaired the ability of the animal to reject the foreign graft. The T cell is involved in this kind of rejection as well as in cancer cell rejection, and its ability to function is impaired if you eat a high-fat diet. In other experiments, phagocytosis was studied. Another saturated fat, methyl palmitate, was found to markedly impair phagocytosis for at least seventy-two hours after a single injection. There is great controversy and discrepancy among experiments dealing with polyunsaturated fats and their effect on the immune system. Some investigators report that a diet low in polyunsaturated fats enhances the immune system, and some show no such enhancement. In all these studies, it must be kept in mind that the significance of the results is unclear because large amounts of lipids were used. It has not been determined whether physiological doses of the same lipids have similar effects on the immune system as do these large amounts of lipids.
The Epstein-Barr virus may manifest itself as entirely different diseases in different people as a result of varying degrees of impairment of the immune system. The extent to which the immune system is weakened or damaged is partly determined by the nutritional status of the individual prior to infection. Epstein-Barr virus is implicated in a relatively benign disease, infectious mononucleosis; a slow-growing cancer, nasopharyngeal cancer; and a rapidly growing, usually fatal cancer, Burkitt's lymphoma; as well as other diseases. Why does one person's immune system permit infectious mononucleosis to develop and another person's immune system permit a fatal cancer to develop? The answer is very complex and not well defined at all, but nutritional status is a factor. Your nutritional status is determined by how well your diet and supplementation program is meeting your nutritional needs. The better your nutritional status, the better your immune system, and the better off you will be.