Supplements useless in cancer prevention, despite marketing claims

It is a multi-billion dollar industry thanks to as many as half of all US adults buying into their marketing campaigns, but the supplement industry lacks any evidence that comes even remotely close to supporting such a massive and influential business. The fact that some of them are marketed as anti-cancer, or as cancer preventives, is potentially dangerous and demands government regulation, according to researchers from the University of California. Their work has been published in the Journal of the National Cancer Institute.

What they found was the only evidence that dietary antioxidants -- including beta-carotene, alpha-tocopherol, and vitamin C -- did in fact encourage growth of normal cells and tissue and inhibit growth of abnormal tissue was in pre-clinical trials--in the lab, in other words. Trials featuring actual humans never supported the pre-clinical evidence.

Furthermore, their review determined that:

• Beta-carotene did not prevent recurrence of (non-melanoma) skin cancer
• Beta-carotene, alpha-tocopherol, and vitamin C failed to prevent recurrence of colonic adenomas
• Beta-carotene, vitamin A, and alpha-tocopherol did not prevent lung cancer
• Vitamins C and E did not protect against cancer
• Alpha-tocopherol, vitamin C, and beta-carotene had no effect on cancer incidence or mortality
• Beta-carotene and vitamins A, C, and E -- alone or in combination -- did not prevent gastrointestinal cancers
• Alpha-tocopherol and selenium failed to prevent prostate cancer in average-risk men

Source: Medpage Today