DIET SUPPLEMENTS NO GOOD FOR CANCER

Results of the Alpha-Tocopherol, Beta-Carotene Prevention Study have found no reduction in the incidence of lung cancer among male smokers after five to eight years of diet supplementation with alpha-tocopherol (vitamin E) and beta carotene, according to the New England Journal of Medicine (April 14).

In fact, the placebo-controlled study raises the possibility that these supplements may actually have harmful as well as beneficial effects - men who received beta carotene were found to have lung cancer more frequently than those who did not receive beta carotene. A total of 29,133 male smokers from Finland entered the study, and there were 876 new cases of lung cancer diagnosed during the study. No reduction in lung cancer incidence was seen in the alpha-tocopherol treated group, although the incidence of prostate and colorectal cancers was reduced. Total mortality was 8% higher in the group who received beta carotene.

US National Cancer Institute senior investigator Demetrius Albanes commented that although beta carotene was linked to an increased risk of cancer, those patients who received placebo but had the highest levels of beta carotene from their normal diet had the lowest incidence of lung cancer. Investigators feel that this may mean that there is something in foods containing beta carotene that protects against disease. Alpha-tocopherol had no apparent effect on total mortality, although more deaths from hemorrhagic stroke were observed in this group. The authors feel that in view of the existing data on beta carotene, an adverse effect seems unlikely. And David Kessler, US Food and Drug Administration Commissioner, said that existing studies on beta carotene are good enough that there is no reason to think about taking the product off the market.