Alternative Cancer Therapies Go Mainstream
What they are: Megadoses of vitamins or minerals that are purported to prevent the formation or growth of cancer cells. Key nutrients under investigation are vitamin E and selenium.
Summary: Preliminary findings show real promise. Be sure to check with your doctor about dosage.
The evidence: In findings published in the May 1998 issue of the British Journal of Urology, 974 men with prostate cancer were given either 200 micrograms of selenium supplements or placebo pills daily for a period of about 4.5 years. Men in the supplement group had a 63% reduction in the incidence of new prostate tumors. They were also significantly less likely to die from all forms of cancer within the 6.5 years that researchers tracked them. Three large randomized trials funded by the National Cancer Institute found that taking vitamin E and selenium significantly lowered lung cancer risk.
Side effects and cautions: At high doses, selenium can be extremely toxic. Ingesting vitamin E at doses higher than 1,000 IUs can thin the blood and cause internal bleeding. Experts caution against taking very high doses of either of these supplements without consulting a doctor.
What it is: A strict diet that eliminates meat and dairy products and derives 50% to 60% of its calories from whole grains, 25% to 30% from vegetables, and the rest from beans, seaweed, and other plant sources.
Summary: There is strong evidence that plant-based diets can help prevent cancer. The effectiveness of these diets as a treatment remains controversial.
The evidence: Although there is no direct evidence yet that a macrobiotic diet will prevent or slow the growth of tumors, there is plenty of evidence that its components are potent cancer-fighters. In a report in the journal Nutrition and Cancer in August 1998, epidemiologist Larry Kushi, PhD, and his colleagues showed that a diet very rich in whole-grain foods can protect against a variety of cancers. Hundreds of studies have found an association between vegetable consumption and a lower risk of many forms of the disease, including colon, lung, prostate, and breast cancers, according to epidemiologist John Potter, PhD, of the Fred Hutchison Cancer Research Center in Seattle. More clinical trials are under way.