Washington: Resveratrol, a compound in red wine and grape skin, may help prevent alcohol-related head and neck cancers, researchers, including one of Indian-origin, have found. "Alcohol bombards your genes. Your body has ways to repair this damage, but with enough alcohol eventually some damage isn't fixed. That's why excessive alcohol use is a factor in head and neck cancer," said Robert Sclafani, from the University of Colorado Cancer Centre. "Now, resveratrol challenges these cells - the ones with unrepaired DNA damage are killed, so they can't go on to cause cancer. Alcohol damages cells and resveratrol kills damaged cells," said Sclafani. The body metabolises alcohol by converting it first to acetyl aldehyde and then the body uses aldehyde dehydrogenase (ALDH) to further convert it to acetic acid, which is excreted. The partially processed state of alcohol, acetyl aldehyde, is a carcinogen and produces "cross links" in DNA. "With enough alcohol, the body can get behind and end up with a backlog of acetyl aldehyde," Sclafani said.
"Increased exposure to alcohol, loss of the ALDH gene that helps the body process alcohol, and loss of the ability to repair DNA cross links all result in increased cancer risk," said Sclafani. With hard alcohol that's the end of the story: increased risk for head and neck cancer due to increased production of acetyl aldehyde. Hard alcohol is an alcoholic beverage produced by distillation of a mixture produced from alcoholic fermentation, such as wine. "But when you look at epidemiological studies of head and neck cancer, alcohol is a factor, but by alcohol source, the lowest cancer incidence is in people who drank red wine," Sclafani says. "In red wine, there's something that's blocking the cancer-causing effect of alcohol," said Sclafani.
"The more you drink, the more you accumulate DNA damage, and the more chance that one or more cells will accumulate the specific type of DNA damage that can cause cancer. Now, resveratrol takes out the cells with the most damage - the cells that have the highest probability of being able to cause cancer," Sclafani said. According to Sclafani, the resveratrol in red wine (and other chemopreventive chemicals found in grape seed extract) is not a magic bullet that can completely undo the cancer-causing effects of alcohol, but by killing the most dangerous cells it may decrease the probability that alcohol use will cause cancer. Sclafani and colleague Dr Rajesh Agarwal plan to test resveratrol in the prevention and possibly treatment of head and neck and other cancer types.
