Colon cancer prevention

Selenium may reduce the risk of colon cancer, say researchers who re-analyzed three trials on more than 1,700 people who had already had one precancerous colon polyp.

The studies were designed to see if wheat bran and other high-fiber foods could prevent new polyps (they didn't). When researchers checked blood selenium levels, they found that people who had higher levels when the studies began had a 34 percent lower risk of precancerous colon polyps than those with lower levels.

What to do: The Selenium and Vitamin E Cancer Prevention Trial (SELECT) on 35,000 men--which is looking primarily at prostate cancer--will also examine selenium's impact on colon cancer risk. Until the study ends in 2013, it's sensible to take a multivitamin containing the Daily Value for selenium (70 micrograms). (Levels in foods vary depending on how much selenium is in the soil where they're grown.)

J. Nat. Cancer Inst. 96: 1645, 1669, 2004.