Cancer: A Role for Nutritional Supplements
by Kim Schoenhals
Cancer is one of the leading causes of death in America, second only to heart disease. There were approximately 553,400 cancer deaths in 2001--more than 1,500 people per day--according to the American Cancer Society (ACS) (www.cancer.org). ACS also estimated the total number of newly diagnosed U.S. cancer cases in 2001 was 1,268,000, excluding basal and squamous cell skin cancers--of which more than 1 million cases were diagnosed on 2001--and in situ (noninvasive cancer) carcinomas, except urinary bladder. Lung cancer is the leading cause of cancer death in the United States (there were 157,400 lung cancer deaths in 2001), followed by colorectal cancer (56,700), breast cancer (40,600) and prostate cancer (31,500).
The single most important risk factor for cancer is age, according to the National Institutes of Health (NIH). Aside from age, smoking status and alcohol intake are telling signs of cancer risk. Approximately 172,000 cancer deaths were caused by tobacco use in 2001, and about 19,000 cancer deaths may have been related to excessive alcohol use, according to ACS. Obesity also increases the risk of certain cancers. The relative risk of breast cancer increases by 50 percent in obese women, and the risk of colon cancer increases 40 percent in obese men.
For those Americans who do not use tobacco, dietary choices and physical activity become the most important modifiable determinants of cancer risk. More than a dozen food-derived agents are currently being studied for their application in cancer prevention, according to James Crowell, Ph.D., who--with his colleagues at the National Cancer Institute (NCI)--presented a symposium as part of the Experimental Biology meeting in Washington, D.C., April 17 to 21, 1999, on the progress of cancer chemoprevention and the development of diet-derived chemopreventive agents.1 Some compounds for which NCI is funding academic research include green and black tea polyphenols, soy isoflavones, vitamin D, vitamin E, selenium, calcium and indole-3-carbinol. "Many pharmacologically active compounds will come out of foods," Crowell said. "Because the food industry has not typically had experience in doing this type of research, I think the government has a good part to play. ... It's important that some of these [food-derived agents] be investigated in a thorough and systematic scientific way, as you would for a drug."
Because a poor diet is a significant risk factor for cancer development, vitamin and mineral intake is also closely correlated with reducing the risk of cancer. Aside from vitamin and mineral supplements, various carotenoids, botanicals and essential fatty acids may have roles in the prevention of cancer.
Vitamins and Minerals
Vitamins and minerals are among the most often studied supplements on the market and the most popular with consumers. Cancer patients are more likely than the general population to turn to alternative remedies for adjuvant support. According to the Natural Marketing Institute's Health & Wellness Trends Database--three years of trended data including more than 2,000 consumer household respondents--71.1 percent of consumers who have cancer use multivitamin and multimineral supplements compared to 66.8 percent of the general population. In addition, cancer patients are more likely to believe in the benefits of multivitamin and mineral supplements than the general population. While 33 percent of the general population "agrees completely" that vitamins and minerals are beneficial in the prevention of certain health conditions, 38.9 percent of cancer patients say the same, according to NMI.
One of the most well known bunch of vitamins and minerals are antioxidants. With their free radical fighting skills, antioxidants protect the body from oxidative damage, which is considered a major factor in cancer development. One antioxidant all-star is vitamin E. Accord