There is good, although not unequivocal, epidemiological evidence to suggest that dietary carotenoids have a protective effect against cancer and other degenerative diseases such as cataract and macular degeneration of the retina. For example, beta-carotene supplements can reduce the burden of leukoplakia and other preneoplastic lesions in subjects at high risk of developing oral cancer.
Beta-carotene appears to protect primarily against cancer progression, while retinoids and carotenoids with oxy-groups seem to have a protective effect at the earlier stages of carcinogenesis.
The mechanisms mediating these effects are not certain. The antioxidant activity of carotenoids is receiving much attention in this regard. Another hypothesis implicates the protein connexin, which is responsible for gap junction communication between cells, and whose synthesis may be enhanced by carotenoids and retinoids.
Ref. Bates, C.J. (1995), Vitamin A, Lancet 345, 31-35.
Add information to this page that would be handy to have on hand during a consultation, such as a web address or phone number. This information will always be displayed when you visit this page