DOCTOR'S VIEW ARCHIVE
Previous observational studies have indicated that people who consumed foods that were high in beta carotene had lower risk of certain cancers and heart disease. It was never determined whether the lowering was from beta carotene, other associated nutrients, dietary habits in these individuals, or nondietary lifestyle features. Despite the lack of data as to the reasons for the risk reductions, sales of beta carotene supplements increased.
In a recent study, published in the New England Journal of Medicine, Charles H. Hennekens, M. D. and associates at the Harvard School of Public Health followed over 22,000 adult males for 12 years, half randomized to take beta carotene, half randomized to take placebo. They found "neither benefit nor harm in terms of the incidence of malignant neoplasms, cardiovascular disease, or death form all causes."
In a second study involving centers throughout the U.S., published in the same issue of the New England Journal of Medicine, Gilbert S Omenn, M.D., Ph.D. and associates followed over 18,000 smokers, former smokers, and workers exposed to asbestos each taking beta carotene and Vitamin A for an average of 4 years. They reported no benefit and possible harm related to chance of developing lung cancer and on the risk of death from lung cancer, heart disease, or other causes.