Since cancer has become the plague and one of the greatest fears of the modern technological, chemical age and, overall, cancer treatment, other than for certain malignancies, has not to date been very successful, prevention of cancer is the only sensible approach. The relationship of diet to cancer came of age in the 1980s. With our new knowledge, we can clearly now do something about the threats of cancer and our future. Caring for ourselves and others as if we really love life and have a desire to live will win over all possible disease!

Chapter 11, Environmental Aspects of Nutrition, contains a fairly detailed discussion of cancer—its genesis, potential offending agents, dietary concepts, prevention ideas, and so on. Here I want to focus more on general nutrition and supplements and their importance in preventing cancer.

Two decades ago, it was difficult to find any major institutions, doctors, or groups like the medical associations or the American Cancer Society, that would admit that there were any ties between cancer and nutrition. Now the nutritional and environmental influences on the genesis of cancer, the second biggest killer of the American adult population, have been fairly well accepted as key components in this disease. A big breakthrough came with the 1977 Senate Select Committee’s Dietary Goals for the United States, listing cancer as one of the major degenerative diseases (cardiovascular disease and diabetes are others) that are linked to improper diet. The committee’s suggestions of lower fat, higher fiber, and more natural foods are definitely a part of the cancer-prevention diet. An important report called Diet, Nutrition and Cancer, compiled by the National Academy of Sciences and released in 1982, gave further credence to the relationship between diet and cancer and offered more specific dietary suggestions. And in 1988, the U.S. Department of Health and Human Services published a major manuscript by C. Everett Koop, M.D., entitled The Surgeon General’s Report on Nutrition and Health. It discusses the relationships between nutrition and our common degenerative diseases, including cancer.

But cancer is a multifactorial, multidimensional disease. While nutritional and environmental influences are definite components, physiological, social, emotional, psychological, and spiritual factors are also important. Therefore, the prevention and treatment of cancer must deal with all of these aspects of life.

The aging process itself increases cancer risk, but particularly if we do not take good care of ourselves. Poor nutrition can lead to many functional problems, such as lowered immunity and slower cell repair. The increased exposure to carcinogens is no help either. (See more on this in the Anti-Aging Program). To much of the medical profession, cancer prevention means primarily early detection—more exams, x-rays, mammograms, and biopsies—so that the necessary surgery, drugs, and radiation can be applied sooner to prevent an untimely death. However, prevention of cancer is much more than early detection—it means not creating the disease. A good diet and stress management are important cancer preventives. A strong, healthy immune (defense) system is also an essential part of this plan (see the preceding program on Immune Enhancement). With a strong immune system, even the few cancer cells that might be regularly generated would be easily removed from the body. Put simply (according to current thinking), it takes both the disease of the cells and the failure of the immune system together to create cancer—in other words, the effect of potential carcinogens on an already unstable body.

Michio Kushi, author of the in-depth text The Cancer Prevention Diet, believes that cancer is caused not so much by carcinogens per se as by the imbalance in the body caused by improprieties of diet that allows the agents to create problems. He advocates the "unified theory of disease," which sees the internal imbalance between yin and yang as the primary cause of cancer and most diseases. It is the "duality," or seeing of body parts or diseases as separate from our entire being, that allows us to treat even the mildest of symptoms as an enemy and not as an ally trying to guide us in a new direction. As we continue to approach our health in this way, we create further diversions from unity and manifest more-difficult-to-treat acute and chronic problems. Cancer itself, as is true of most disease, can be seen as a lack of harmony with our environment and a diversion from our inner truth.

This program is suitable for most everyone, especially those in a high-cancer-risk group. That includes men and women over 40 or 50 years old and people with a family history of cancer, especially women with a family history of breast cancer. Smokers, people with a dietary history that includes cancer risks, and those who have been exposed to known carcinogens will also benefit.

What really causes cancer? Is it a virus or genetic code, the effect of carcinogens on cellular growth, or a weakened immune system? Is it a poor, "cancer-promoting" diet? Or does it have to do with the psychological factors influenced by stress, poor attitude, or low self-esteem? We do not really know; cancer seems to be linked to all of these factors. Family history is definitely a factor, and if someone in our families has had cancer, that should increase our watchfulness for this disease as well as encourage us to use early detection procedures.

Discussion of cancer risks and promoting factors could easily fill a book. I want to keep it simple. Below I list the eleven main cancer risks, followed by a more extensive discussion of various factors that may add to our chances of developing cancer sometime in our lives. One of the difficult tasks in researching many cancer risks is that cancer can often take 30–40 years from the time of exposure to a carcinogen for it to manifest as a physical tumor. But the following list clearly shows that the promotion of cancer involves almost exclusively diet, environment, and lifestyle. Problems that result from pharmaceutical medicines or viral conditions that weaken immunity and allow cancer to develop more easily are probably rarer, and usually even the factors that predispose us to these conditions are areas over which we have some control.

1. Smoking
2. Dietary excesses—fats (mainly saturated, fried polyunsaturated oils, and cholesterol); protein; obesity (calories)
3. Undernutrition—deficient fiber and nutrients such as vitamins C and E, beta-carotene, selenium
4. Occupational chemicals
5. Food chemicals—pesticides, additives, hormones
6. Air and water pollution
7. Excess sunlight and radiation
8. Certain pharmaceutical drugs—estrogen, metronidazole (Flagyl), lindane (Kwell), or griseofulvin
9. Alcohol
10. Viruses
11. Psychological influences—such as personal changes, loss of loved one, grief, divorce

Smoking, mainly of cigarettes, is a primary cancer risk and is correlated with nearly all lung cancer. It is also a factor in cancers of the mouth, throat, and larynx and possibly others. Pipe and cigar smoking produces higher incidences of mouth cancer but less of lung. Cigarette smoke acts synergistically with alcohol, asbestos, and other carcinogens in air, water, and food to further increase cancer risk and rates. It is likely that naturally grown tobacco rolled in untreated paper poses less cancer risk; the chemical production and treatment processes involved in manufacturing a pack of cigarettes are definitely an added cause for concern. Regular marijuana smoking may also be a factor in cancer, though more research on this is needed. Cigarette smoking is clearly the largest and most preventable cancer risk.

Excess fats in the diet definitely increase the incidence of breast, colon, and prostate cancer and possibly others, such as uterine or ovarian cancer. The fats of most concern include saturated animal fats, as found in meats and dairy products; fried or rancid oils; hydrogenated and refined oils, and cooked polyunsaturated fatty acids (PUFAs). Rancid oils and foods cooked in oils cause more free-radical irritation (as do high amounts of PUFAs), mainly from lipid peroxides, and these act as mutagens and carcinogens. Excess protein in some studies correlates with cancer rates, but most of the higher protein foods also contribute to higher fat levels and this type of diet will often lead to more general body congestive and degenerative processes.

Obesity is definitely correlated with higher cancer rates. Colon, rectum, and prostate cancer rates are higher in obese men, while obese women have increased risks of cancer of the breast, cervix, uterus, ovary and gallbladder. It is not totally clear whether the risk is posed by the obesity itself, higher caloric intake, or by the many associated factors, both nutritional and psychological (overweight people tend to hold things in).

Deficiencies of many nutrients are implicated in some cancers. Low fiber in the diet is probably the biggest culprit, mainly in the increasing problem of colon cancer. Slow transit time through the intestinal tract, allowing more contact to carcinogens, may be the main factor here. Many specific nutrient deficiencies have been correlated with various cancers. Vitamin A and beta-carotene deficits increase the incidence of lung and mouth cancer, especially among cigarette smokers, and are also implicated in cancers of the skin, throat, prostate, bladder, cervix, colon, esophagus, and stomach. Also of concern is selenium deficiency, which we now know may increase the risk of many cancers, mainly of the breast, lungs, colon, rectum, and prostate, as well as skin, pancreas, and intestinal cancer and leukemia. Vitamin C may reduce the carcinogenicity of nitrosamines and other chemicals; vitamin C deficits may increase cervical, bladder, stomach and esophageal cancers, as well as the general carcinogenic process. Vitamin E deficiency definitely weakens the body’s ability to balance rancid oils and free radicals, and this increases cancer risk. Other mineral deficiencies implicated in cancer include molybdenum deficiency in esophageal and stomach cancer; zinc deficiency in cancer of the prostate, colon, esophagus, and bronchi and general immune system weakening; and possibly iodine and iron deficiencies.

Occupational chemicals are a topic of great concern. Many workers at home or in jobs are exposed to a wide range of chemicals with varying carcinogenicity. Possible agents include nuclear radiation and fallout, chemicals used in dry cleaning and other cleaning supplies, benzene, coal tar and its derivatives, asbestos, arsenic, PVC, gasoline and petroleum products and other hydrocarbons, pesticides, cosmetic chemicals, and many others. A more detailed discussion is included in Chapter 11, Environmental Aspects of Nutrition. Cigarette smoking also increases the risks from these occupational hazards.

Food chemicals are another big topic. There are many possible carcinogens, most of minimum risk but often cumulative, and we have much to learn about possible interactions of multiple carcinogens. Chemicals may be added to food during growth, manufacture, or preparation, and some are even made by the foods themselves or in combination with other microorganisms.