It was too good to be true -- the hype that drinking wine leads to strong hearts and healthy bodies. While it does appear true that wine exerts some mildly beneficial effect on the heart, new research reveals the dark side of the "fruit of the vine."
A study of over one million women at Oxford University in England found that drinking even one glass of wine daily leads to a significant increase in the risk of certain cancers. The study followed 1.28 million women, ages 50 to 64, for a period of seven years. Among those who drank one small glass of wine daily, the breast cancer risk rose by six percent. Those who drank two glasses a day doubled that risk, showing a 12 percent increase in breast cancer, a 22 percent rise in laryngeal cancer, and significant increases in cancers of the rectum, liver, and mouth. Risk continued to rise with each daily drink: breast cancer increased by an additional 12 percent and rectal cancer risk by another 10 percent with each glass of wine, leading the researchers to conclude that alcohol consumption accounts for about 13 percent of all breast, liver, rectal, and upper digestive tract cancers in women.
"There were no minimum levels of alcohol consumption that could be considered to be without risk," said study director Dr. Naomi Allen. Other members of the research team -- Michael S. Lauer, MD, and Dr. Paul Sorlie -- commented that the enormous size of this study made the results particularly significant. "From the standpoint of cancer risk, the message of this report could not be clearer," they wrote. "There is no level of alcohol consumption that can be considered safe."
If you're thinking it's time to dump the merlot and take up beer, forget about it. The researchers concluded that it's not wine per se causing the rise in cancer -- it's alcohol of any sort. In fact, a separate study out of the Fred Hutchinson Cancer Center in Seattle, Washington, and just reported in the journal Cancer Epidemiology Biomarkers and Prevention, the researchers found no difference in breast cancer risk when comparing wine, beer, and liquor. In that study, the link between drinking and breast cancer was even more startling than in the "Million Women Study." The researchers found that women who had 14 or more drinks a week increased their risk of developing breast cancer by 24 percent. And yet another study -- this one sponsored by Kaiser Permanente Healthcare last year -- found that drinking three or more alcoholic beverages daily increases risk by 30 percent.
How does this new information square with the studies finding that the resveratrol in red wine confers beneficial cardiovascular effects? According to the aforementioned study director, Dr. Naomi Allen, "Given that in middle-aged women, that is women in their 50s to 60s, the risk of developing cancer, particularly breast cancer, is much higher than the risk of developing heart disease, the risks seem to far outweigh the benefits, at least for this age group." Then again, there is, in point of fact, very little resveratrol in red wine. Drinking wine for resveratrol is pretty much a meaningless exercise. If you want the benefits of resveratrol, you need to supplement.
In contrast for men, another study published last year in the journal Carcinogenesis, found that resveratrol reduced the risk of prostate cancer by 87 percent. But according to the director of that study, Dr. Coral Lamartiniere, the results may have something to do with the amount of resveratrol in the particular wine given to subjects. "Different red wines have different potencies of resveratrol. Cabernet sauvignon has the highest," he says, noting that it isn't clear how much was in the red wine consumed by the women in the other studies. Then again, I beg to differ with Dr. Lamartiniere. As I mentioned earlier, the amount of resveratrol in any wine is minimal. It is unlikely that the health benefits of wine are associated with resveratrol.
In fact, the evidence seems to point to some carcinogenic factor other than the low resveratrol content in wine. According to Dr. Allen, "There is evidence that moderate alcohol intake at the levels studied here increases circulating levels of sex hormones, which are known to be associated with an increased risk of breast cancer." Beyond whatever impact the alcohol content in wine exerts on hormonal balance, there's also the fact that wine has enormous heavy metal content, plus pesticide residues. As I wrote in a blog last November, "Many wines contain heavy metals up to 200 times the amount considered safe...Most wines [evaluated by researchers] showed a Toxic Hazard Quotient (THQ) of 50 to 200. To give you perspective, seafood considered dangerous usually falls between a THQ of one and five." I also note in that same blog that in various studies, 75 percent of European wines were contaminated with multiple pesticides.
Although, the warning about wine would seem to apply primarily to women because of the strong breast cancer link, men should think twice, too. The Million Women study showed a strong link between wine and many types of cancer -- not only breast cancer. Also, heavy metals and pesticides don't have gender preferences; it makes sense that whatever carcinogenic or mutagenic effect they exert would impact both sexes. Just remember -- a few weeks ago the medical establishment was all in favor of women downing a nightly glass.
At the least, if you're going to keep drinking, go for organic Cabernet from Italy or the US, where the heavy metal and pesticide content is a bit more under control -- and drink only on special occasions.