Headline August 8, 2013: Red wine protects from colon cancer “According to a study … from researchers at SUNY Stony Brook which compared the drinking habits of red and white wine drinkers with similar lifestyles … consuming three or more glasses of red wine a week may help to reduce the risk of colon cancer. They found that drinking red wine reduced the risk of colon cancer by 68 per cent while drinking white wine did not. The researchers believe it is the resveratrol in red wine that provides the protection.”
Headline August 10, 2013: Dietary supplement resveratrol is unlikely to have impact on cancer “…researchers at the Medical University of South Carolina, USA, report results from a study of resveratrol in healthy human volunteers. They found that oral resveratrol is actually broken down to an inactive form very rapidly, so it’s unlikely that supplements have any effect.”
Is it possible that both of these findings are true? The answer is yes, but only if it is something other than the resveratrol that is providing the protective effect of drinking red wine – contrary to the presumption of the researchers at SUNY. These two seemingly contradictory headlines point to a dilemma that has come to define the issue of healthy drinking: the assumption that resveratrol is the whole story, a proxy for red wine without the alcohol.
It’s an easy enough assumption to make, and in fact I gave it a fair amount of consideration in my book. We know that red wine drinkers have better cognition as they get older, lower overallrates of cancer, diabetes, osteoporosis, Alzheimer’s, and a host of other scourges of aging. Conveniently, resveratrol has specific effects in laboratory studies to explain each of these benefits: breaking down the amyloid plaques in neural tissue associated with Alzheimer’s, estrogen-like properties for osteoporosis, or down-regulating overactive genes in cancer cells. The problems are that levels of resveratrol needed for these effects are generally much higher than what is achievable with healthy wine consumption, and absorption of resveratrol after oral ingestion is highly variable (and quickly metabolized, as the group at South Carolina determined.)
It may turn out that resveratrol is indeed useful as a cancer fighter, and there are a handful of clinical trials on the subject (full list available here.) Because the two studies mentioned in this article are both clinical trials, they deserve a higher level of consideration than lab studies on animals or cells in tissue culture. Interestingly, both trials largely confirm what previous ones have found: drinking red wine in moderation is healthy, resveratrol supplementation remains to be proven beneficial.