'Vitamin pills may cut effects of cancer drugs'Submitted by lastmovement on Wed, 05/28/2008 - 22:04
Vitamin supplements could reduce the effectiveness of cancer treatments, experts have warned.
Chemotherapy and radiation treatment kill tumours by inducing the creation of free radicals – destructive molecules which damage DNA and proteins.
Antioxidants mop up free radicals, which is generally beneficial to health. But supplements such as vitamin E and beta carotene may also reduce the potency of anti-cancer treatments, according to US researchers.
Dr Brian Lawenda, from the Naval Medical Centre in San Diego, California, reviewed evidence from a number of trials.
Of three randomly controlled radiotherapy studies, one investigation showed that antioxidant supplements were associated with lower survival rates.
No chemotherapy trials reported lower survival rates for patients on antioxidants, but the researchers said none of the studies was sufficiently large to spot such differences.