Supplements may increase risk of GI cancer

Some vitamin and antioxidant supplements appear to increase the risk of gastrointestinal cancer, according to new research. A review of 14 major studies involving more than 170,000 people found statistically significant increases in deaths from gastrointestinal cancer among people who took supplements with beta carotene and vitamins A, C and E. Some supplement combinations appeared more dangerous; people who took supplements with both beta carotene and vitamin A showed a 30 percent higher risk, while supplements that contained beta carotene and vitamin E showed a 10 percent higher risk. However, four of the 14 studies found a reduced risk of cancer among those taking selenium supplements.

Researchers suggested that supplements might interfere with apoptosis, a naturally occurring process in which the body destroys abnormal cells. The American Cancer Society recommends ensuring appropriate amounts of antioxidants by eating a balanced diet. In an accompanying editorial, Dr. David Forman of Leeds University in England and Dr. Douglas Altman of Cancer Research United Kingdom, said "9,000 in every million users of such supplements will die prematurely as a result," if the studies findings are correct, but also noted that the review "is a work in progress and does not offer convincing proof of hazard."