Carotenes In Cancer Prevention

A variety of published studies show that a high carotenoid intake is directly related to a decreased risk of cancer. The carotenoids are the pigments that give vegetables such as carrots, squash, and tomatoes their bright colors. All yellow and orange fruits and dark-green leafy vegetables have these compounds. Carotenoids were first discovered in carrots, which is how they got their name.

High dietary intake of carotenoids is known to result in high concentrations of carotenes in the bloodstream. A large study of the effect of beta-carotene in cancer prevention was reported in the American Journal of Nutrition (1991 : v.53, 2605-2645). This study involved 25,802 volunteers in rural Washington County, Maryland, representing about 30% of the population of the the whole country. Blood samples were carefully drawn and kept frozen during a follow-up period of more than 10 years. A total of 436 people developed cancer in this interval. The cancer cases were matched to 765 controls of the same age, then all of the case and control serum samples were analyzed, with a focus on cancers of the colon, rectum, pancreas, lung, skin, breast, prostate, and bladder.

Results of the study showed the ff: High serum beta-carotene levels showed a strong protective effect for lung cancer, and a somewhat weaker protective effect for melanoma and bladder cancer. High levels of serum lycopene, another major carotenoid, were strongly associated with a reduced risk of pancreatic cancer and less strongly associated with protection from bladder and rectal cancer. The study shows a reduced risk of cancers, particularly lung cancer, with increasing consumption of beta-carotene, researchers concluded.