The medical literature is filled with studies looking at diet , nutrition and cancer.
Mounting evidence shows a clear relationship between various nutrients and cancer, suggesting that good nutrition is a powerful preventive strategy.
That strategy can play an important role as an adjunct therapy for those who already have the disease.
- Vitamin A. Solid research has shown that vitamin A reduces the risk of many cancers, including cancers of the bladder, esophagus, stomach, lung, prostate, cervix, head, neck, bladder and skin, as well as the cancer of the blood cells known as leukemia. Vitamin A is an important immune system booster, helping to keep the thymus and lymphoid tissue in good shape. Good amounts of vitamin A are needed to make sure the total number of T- and B-cells (immune-system cells that help fight off invaders) remains high. Vitamin A even helps those who already have cancer respond to treatment. In a study of 37 women about to undergo chemotherapy for breast cancer, researchers found that 87 percent of those with high levels of vitamin A responded to treatment, compared to only 36 percent of those with low levels.’ Good sources of Vitamin A include liver, cheese and milk.
- Beta carotene. Beta carotene, a member of the carotenoid family, is the “plant form” of vitamin A. Some of the beta carotene that we eat is converted by the body into vitamin A. Consuming large amounts of foods containing beta carotene has consistently been found to offer protection against cancers of the cervix, colon, esophagus, stomach, larynx, lungs and skin. As the American Journal of Clinical Nutrition points out, “One of the most consistent epidemiological findings in nutrition research has been an association between beta-carotene intake and status and reduced lung cancer risk.
- Thiamin (Vitamin Bi). Low levels of thiamin intake may be associated with a greater risk of prostate cancer. A deficiency of Bi can lead to shrinking of the thymus, the “school” for immune-system cells, as well as a deficiency of T-cells and B-cells. Vitamin Bi can be found in garbanzo beans, split peas and whole grains.
- Riboflavin (Vitamin B2). The intake of riboflavin may be inversely correlated with the risk of cancers of the prostate and esophagus. That is, the more riboflavin one gets, the smaller the risk. Lack of B2 can lead to problems in producing antibodies and reduced numbers of T-cells and B-cells. Vitamin B2 sources include broccoli, collards and dried beans.
- Folic acid. This member of the B-family of vitamins may help to prevent cancer of the cervix. A test of the folic acid/cervical cancer hypothesis involved 47 young women who were taking birth control pills. They all had mild or moderate cervical dysplasia, a possibly precancerous condition. Some of them were given folic acid, others a placebo, on a daily basis. Three months later, the women receiving the folic acid showed significant improvement.
- Vitamin C. Linus Pauling, Ph.D., sparked a tremendous controversy with his suggestion that vitamin C may help to prevent or cure cancer. Although the medical establishment remains firmly set against the double-Nobel-prize winner’s theories, mounting evidence suggests that the late Dr. Pauling was right. We now know that vitamin C makes the immune system’s white blood cells more mobile. It stimulates the T-cells, which engage cancer in “hand to hand” combat; the B-cells, which produce “guided missiles” that lock in on cancer cells; and the macrophages, which “engulf’ and destroy foreign bodies. Good food sources include cantaloupe, papaya and spinach. Some 90 epidemiological studies have looked at the use of vitamin C or foods containing it as a means of preventing cancer. Most of those studies concluded that there is evidence that vitamin C protects against cancers of the pancreas, stomach, oral cavity and esophagus. There is strong evidence that the vitamin protects against cancers of the breast, rectum and cervix. And there is newer evidence suggesting that vitamin C plays a major role in preventing lung cancer.
- Vitamin E. Although excessive vitamin E can hamper the immune system, good amounts are needed in order to keep the numbers of T-cells and B-cells up to proper levels. As an antioxidant, vitamin E helps protect the body against the cancer-causing effects of oxidation. Food sources include wheat germ, nuts and green, leafy vegetables. Good levels of vitamin E in the blood have been linked to protection against cancers of the cervix, stomach, bowels, breast, head, neck, lungs and skin. When blood was drawn from 766 patients before they were diagnosed with cancer and from 1,419 controls, researchers found that low levels of vitamin E increased the cancer risk by one and a half times. In studies on-humans and animals, vitamin E has been found to enhance the effectiveness of several chemotherapy agents.
- Selenium. Like vitamins A, C and E, the mineral selenium is an antioxidant. As such, it helps to protect the body from the potentially cancer causing effects of oxidation. A lack of selenium slows the body’s ability to produce antibodies when a foreign or dangerous substance appears in the body. Studies have shown that selenium deficiency is associated with increased risk of cancer of the breast, stomach, pancreas, skin and other parts of the body. It’s interesting to note that the amount of selenium in foods depends upon the quantity of selenium in the ground where the food was grown. People living in areas with selenium-poor soil, who are presumably eating selenium-poor foods, are more likely to die of can- cer than those living in areas where the soil is rich in selenium. Foods that are high in selenium include onions, garlic and green beans.