Poor populations around the world that suffer from malnutrition are more susceptible to infection than those who receive adequate nutrition. Investigators studying the relationship between the immune system and nutrition have found that nutrition affects immunity (1,2) and also affects the development of cancer (3,4) either directly or indirectly via the immune system.
The immune system is a complex interaction of blood cells, proteins, and processes that protects you from infections, foreign substances, and cancer cells that spontaneously develop in the body.
In 1989, research at the Shriner’s Burn Institute in Cincinnati showed that administration of a special liquid diet to severely burned patients begun the day they were burned reduced the risk of infection by 50 percent. The special diet consisted of protein, vitamins including A and E, minerals, and iron, as well as omega-3 fatty acids.
White blood cells and antibodies are two major armies of the immune system. These armies arise separately but are related and dependent upon each other for their development and maturity. The Iymphocyte, a specific type of white blood cell, is the main cell involved in cellular immunity. Lymphocytes make up only a small portion of the blood, comprising only about 15 to 20 percent of all white cells. The Iymphocyte population is divided into two large groups, based on particular markings on the outer surface membrane of the cell.
T Iymphocytes, or T cells, are one group of Iymphocytes. They are derived from or are under the influence of the thymus, which is an organ in the neck and front part of the chest that is functionally active in early childhood. T cells are responsible for your defense against cancer, fungi, certain bacteria (intracellular), some viruses, transplant rejections, and delayed skin reactions (tuberculosis skin test). T cells are further divided into several subpopulations: helper T cells and suppressor T cells, those which either help or hinder normal immune cellular function.
Proteins called antibodies or immunoglobulins are produced by the other major group of Iymphocytes, the B Iymphocytes, or B cells. B cells may have their origin in the bone marrow, from which they derive their designation. Antibodies are formed by the B cell in response to a foreign substance introduced into the body. For example, when a person is given a vaccine against polio, antibodies to this foreign substance are made by the B cells. If the polio virus enters the body in an infectious state after a person has been vaccinated, the previously formed antibody, which is circulating in the blood, will attach to this foreign intruder and dispose of it with the help of defending white blood cells or other proteins called complement proteins or a combination of both. The same process of antibody production is initiated by some cancer cells. Killing white blood cells or complement proteins, when activated by an antibody, destroy a foreign-appearing cell by making holes in the foreign cell’s membrane, thereby allowing water to rush in and explode the cell. In 1980, I showed how a white blood cell kills a foreign cancerlike cell Figure 4.1 shows a white blood cell (center) killing several cancerlike cells. Notice that the white blood cell extends feetlike processes that aid in killing the targets. (5)
Phagocytes are another group of white blood cells that reside in the blood and body tissues and are part of your defenses against foreign invaders. These also act as policemen to recognize and dispose of abnormal cancer cells and other foreign substances. Phagocytes can perform this task alone or can recruit antibodies and complement proteins to aid in the disposal.
Immunology and Cancer
The immune system is extremely intricate and finely tuned. If any one aspect of the system malfunctions because of poor nutrition, or if it is destroyed, you may become susceptible to cancer and foreign microbial invaders. The white blood cell army and the antibody army must be functioning perfectly to destroy any cancer cell or foreign invader and prevent either one from gaining a foothold in your body.
The major histocompatibility complex is part of your genetic makeup and is another component of the immune system, acting as a commander of the white blood cell and antibody armies. This complex allows the immune system to recognize the parts of your body so that it does not destroy them as it would destroy foreign substances. At the same time, it can recognize a substance or tissue (histo-) as not belonging to its body and subsequently take the necessary steps to destroy it. The histocompatibility complex is responsible for rejection of transplanted organs such as kidneys and hearts. If the histocompatibility complex is not working properly, a virus capable of converting normal cells to cancer cells may enter the body without being attacked because the immune system did not recognize it as foreign. The virus, if not destroyed, will convert normal cells to cancer cells in a process called transformation, and the cancer will multiply and eventually kill the person.
In 1970, F.M. Burnet introduced the concept of immunosurveillance, which states that killer cells of the immune system watch, or keep a surveillance on, all cells in the body and immediately destroy any cells that start to have a malignant or cancerous potential. (6) There is a lot of evidence to support this concept. The most clear-cut and convincing evidence comes from observations of patients with suppressed immune systems caused by drugs or radiation or an inherited disorder. Patients with inherited immunodeficiencies, whose immune systems do not function normally from birth, or patients whose immune systems acquire a malfunction later in life have one hundred times more deaths due to cancer than the expected cancer death rate in the normal population. (7,8) Kidney transplant patients, who receive drugs to suppress the immune system’s ability to reject the new kidney, also have a higher rate of cancer than would be expected. (9,10) The cancers most frequently seen in these cases are the Iymphomas and epithelial cancers; however, all other types of cancers have been reported as well.
The immune system is relatively immature in infancy, and then runs down and does not function well in old age. These two times of life have the highest incidence of Iymphocytic leukemia. Other immune-deficiency states that can lead to cancer are seen with malaria, acute viral infections, and malnutrition.
Nutrition and the Immune System
Nutritional deficiencies decrease a person’s capacity to resist infection and its consequences and decrease the capability of the immune system. (11) In old age, there is a decrease in skin hypersensitivity reactions, (12,14) a decreased number of T cells, (l5,16) 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. (17) 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 B 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, (18) and their ability to kill cancer and other abnormal cells is impaired. (l9) The amount of antibody is slightly reduced as is the speed with which it attaches to an “enemy.” (20) 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. (21) Much more research has been done concerning the function of the immune system in diabetes. The number of T and B cells is normal in diabetes, but their functions are impaired: phagocytic function as well as cellular killing. (22,23) 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. (24) Researchers E.A. Santiago-Delpin and J. Szepsenwol wanted to know what effects lipids had on T Iymphocytes. (25) 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. (26) 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, (27) and some show no such enhancement.28 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 Iymphoma; 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.
From Cancer and Nutrition by Charles Simone, © 1992. Published by Avery Publishing, New York. For personal use only; neither the digital nor printed copy may be copied or sold. Reproduced by permission.