FOOD CAROTENOIDS AND CANCER PREVENTION - AN OVERVIEW OF CURRENT RESEARCH

Carotenoids are plant pigments that are present in the human diet as m icrocomponents of fruit and vegetables. Since 1980, a consistent bulk of the results from both epidemiologic and experimental studies has st rongly suggested that beta-carotene, a widespread food carotenoid with provitamin A activity, could prevent the onset of cancers, especially lung cancer. Unfortunately, subsequent large-scale intervention studi es failed, with one exception, to demonstrate any chemopreventive pote ncy for beta-carotene supplementation in humans, revealing a lack of k nowledge of the mechanisms involved. In addition to their antioxidant properties, which have long been thought to be the clue to their biolo gical effects, carotenoids appear to have a variety of cellular action s that make them remarkable 'physiological modulators'. Research is st ill needed before new chemoprevention trials can eventually be underta ken on a strong scientific basis.