Antioxidant vitamins and chemoprevention.

Free radicals play an important role in human carcinogenesis and the mechanism of their counteraction by antioxidant vitamins has been reviewed. It seems more likely that these vitamins work in concert rather than acting singly. Currently available data are compatible with the notion that these vitamins act as chemopreventives against some important cancers, e.g. carotenoids for lung cancer, ascorbic acid for salivary gland cancer, tocopherols for head and neck cancers etc. Thus, a greater consumption of fruits and vegetables should be encouraged as they are the natural sources of these chemopreventive, antioxidants along with other protective factors packaged by nature. However, much work still remains to be done to establish the role of antioxidant vitamins in carcinogenesis.