What Is Cancer?
Cancer refers to the growth of abnormal cells, which can displace the normal cells composing tissues. Cancers are often distinguished by their ability to metastasize, spreading to and attacking other organs. There are many different types of cancer, but all arouse fear because of how they cut life expectancy and because of the pain associated with cancer and with conventional therapies (surgery, radiation, and chemotherapy). Although some cancers affect children, they are usually age-related: the older you are, the greater your risk of cancer. In general, cancers take years to develop, and many cancers go undiagnosed until autopsy.
Cancers are caused by mutations, or changes, in the deoxyribonucleic acid (DNA) that programs cell behavior. These mutations generally occur in two ways: through random transcriptional errors when cells normally replicate, and through free-radical damage to DNA. These errors permanently alter the cells’genetic instructions—analogous to being told to turn right on a street instead of left. The immune system recognizes and destroys most abnormal cells, but some are able to evade normal immunity. As a person gets older, a larger number of cell mutations and poor immune surveillance increase the likelihood of cancer.
How Common Is Cancer?
Cancer is the second leading cause of death in the United States and one of the most common causes of death worldwide. A little more than five hundred thousand Americans die of cancer each year. By far, cancers of the lungs and bronchi are the leading causes of cancer-related death in the United States, and they also are a common cause of death among nonsmokers. Breast cancer in women, prostate cancer in men, and colorectal cancer are the next most common types of cancer.
Nutrients That Can Help
Good nutrition and high intake of most micronutrients help preserve the integrity of DNA. Because of this, nearly every nutrient can play an important role in reducing the risk of cancer. However, some nutrients may be more important than others.
Antioxidant nutrients curb the activity of free radicals and, as a consequence, can reduce DNA damage. Selenium, part of the potent antioxidant glutathione peroxidase, has been shown to inhibit dangerous mutations to the flu and coxsackie viruses; vitamin E also prevents mutations to the coxsackie virus. Based on this research, it is highly plausible that selenium and vitamin E also might block virus-induced mutations that could give rise to cancer cells.
In general, vitamins E and C and flavonoids are potent antioxidants that can reduce DNA damage from various types of free radicals. Condiseases trary to some news reports, vitamin C does not increase DNA damage or the risk of cancer. In one case, scientists corrected their warning and apologetically stated that vitamin C actually reduced DNA damage. Another study, performed in test tubes, showed no cancer-causing effect, though newsletter headlines claimed that vitamin C did. Large dosages of vitamin C (10 grams or more daily) do have some benefit in treating cancer, particularly if the vitamin C is delivered intravenously.
Many studies also have found that high-potency supplementation can extend the life expectancy of cancer patients, though these studies are often ignored by oncologists. In terms of prevention, vitamin E and selenium supplements are probably the best supplements for reducing the overall risk of cancer.
The B vitamins play crucial roles in the body’s synthesis and repair of damaged DNA. Folic acid, vitamin B12, vitamin B3, and vitamin B1 may be particularly important, especially in ensuring accurate gene transcription and repair. Some research also suggests that the omega-3 fatty acids reduce inflammation in the digestive tract and may reduce the risk of colon cancer.
Many anti-inflammatory nutrients have been directly linked to lower rates of specific cancers. For example, fish oils are associated with a lower risk of colon cancer. Lycopene lowers the risk of prostate cancer, and one study found that it reduced the size of prostate tumors in men scheduled for surgery.
What Else Might Help?
Cigarette smoke and other pollutants do their damage in large part by disrupting normal DNA transcription and by causing free-radical damage to DNA. Some of the free radicals may be part of the chemical pollutant, other free radicals may be produced when the liver tries to break down the pollutants. Thus, it helps to avoid tobacco smoke, live in a city that does not have serious air pollution, and to minimize exposure to cancer causing chemicals at work and at home. If avoidance is not possible, the evidence suggests that supplemental vitamin E, selenium, and B vitamins— along with a diet with a diverse selection of vegetables—might rank toward the top of a cancer-prevention strategy.
Several aspects of diet are especially relevant in this context. First, high-fat diets promote the growth of many cancers, such as those of the breast and prostate. For prevention and during cancer treatment, it is worthwhile to reduce and, especially, to alter the ratios of specific types of fats. Several compelling studies have shown that fish oils have a cancer suppressive effect. In contrast, corn, safflower, and other vegetable oils high in omega-6 fatty acid promote the growth of cancers.
In addition, researchers at the University of Utah, Salt Lake City, had determined that diets high in trans fats are associated with significant increases in the risk of colon cancer. Given the fundamental roles of fatty acids in health, it would be prudent to avoid a synthetic fat that interferes with other fatty acids. Thus the ideal approach during cancer treatment might be to drastically reduce overall fat intake while emphasizing dietary fish and fish oil supplements. Under these circumstances it might also be best to avoid red meats and even to limit consumption of chicken and turkey.