Is the red wine polyphenol resveratrol an anti-aging serum? Despite an intense focus on the compound in recent years, the existing body of research presents conflicting answers. Researchers from Johns Hopkins University have added another voice to the "no" chorus.
"There are two hot-button areas of aging research right now: caloric restriction—if you want to live longer, eat less—and resveratrol," Richard Semba, a professor of opthamology at Johns Hopkins, told Wine Spectator. "There's some suggestion from animal models that resveratrol could increase lifespan."
To test the polyphenol's effects on longevity, Semba and his colleagues looked at the Invecchiare in Chianti Study, an 11-year, community-based health study of people 65 and older in two villages in Tuscany's Chianti region. Among the study's measurements was the level of resveratrol metabolites, that is, the amount of broken-down resveratrol in study subjects' urine. Since less than 1 percent of the subjects took any nutritional supplements, and since they all lived in the heart of Tuscan wine country, Semba believes that the source of virtually all the resveratrol ingested was red wine.
Semba's objective was to see whether there was any association between resveratrol consumption and lifespan; his data shows that there was not. Among the group that consumed the highest volume of resveratrol, more subjects died during the nine years of follow-up than subjects who consumed less resveratrol. This leads Semba to conclude that resveratrol "has no effects on longevity, at least as obtained in the diet." (Among the many other outcomes measured, however, high levels of resveratrol metabolites were associated with less cognitive decline.)
But there are confounding variables here, Semba warned. "Factors such as age muddy the picture," he said. Moreover, the study was limited to a relatively small population subjected to similar living conditions.
A Valuable Compound, if the Body Can Use It
Another resveratrol-focused study, however, points out that scientists still don't understand how the compound is metabolized.
It's been well-established that resveratrol acts as an anti-inflammatory agent in the body, but new research illuminates one of the mechanisms behind this effect. Resveratrol is a phytoestrogen—a plant-derived compound that binds with estrogen in cells. Other phytoestrogens include soy, sesame, barley, lentils, pomegranate and hops, to name just a few.
But phytoestrogens are often a double-edged sword: While they can reduce inflammation, they can also lead to estrogenic cell proliferation, which may cause thromboembolism, breast and uterine growth, and cancer. "The question is, can you find a phytoestrogen that has the beneficial effects, without the negative effects?" asked Dr. Kendall Nettles, associate professor in the department of cancer biology at the Scripps Research Institute in Jupiter, Fla.
The answer, he found, is resveratrol. Published last month in the journal eLife, Nettles' study argues that "resveratrol is an unusual phytoestrogen in that it seems to be anti-inflammatory, but doesn't induce secondary sexual characteristics," he told Wine Spectator. This means that resveratrol could help provide the benefits of an anti-inflammatory regimen—which could prevent a large range of conditions, from diabetes to dementia to heart disease—without any of the carcinogenic risks of products such as soy.
"The problem," Nettles said, "is that resveratrol has very poor bioavailability. Even if you take it as a supplement, your body doesn't absorb it very well." He noted, however, that understanding the polyphenol's physical mechanisms can help scientists develop targeted drugs. The goal, he said, is "to take things that are found naturally in food and wine, that we know have some benefit, and ask, 'How can we improve that?'"
Red Wine Gives Me a Headache
It's a common refrain—Wine drinkers have long asked whether wine is the cause of their headaches and migraines and, if so, exactly what component of wine serves as the trigger. Obviously too much alcohol can lead to pain, but some drinkers report red wine aggravates even in small amounts.
Few scientific studies have addressed this question directly. But two researchers in Brazil have compiled a literature review of the existing body of evidence, and they believe it can point future research in the right direction. Although the foundation for their premise is anecdotal, Dr. Abouch Valenty Krymchantowski and Dr. Carla da Cunha Jevoux, of the Headache Center of Rio, believe reports of a link between red wine and headaches or migraines are too widespread to be dismissed. They emphasize that sulfites cannot be responsible for headaches, nor do they think histamines are a likely culprit.
Krymchantowski and Jevoux analyzed five small-scale studies that observed directly whether different red wines would trigger headaches both in migraine-prone and non-migraine-prone subjects. The instance of headaches in the cited experiments was high, and the grape varieties used led the authors to conclude that "red wines with more tannins are probably worse in triggering migraine attacks." They conclude that flavonoid phenolic compounds—the chemicals that inform a wine's color, taste and mouthfeel, ranging from tannins to resveratrol—are probably the headache triggers.
"We believe that red wine is indeed a migraine trigger," the authors write. But they concede that the current literature does "not allow definitive conclusions regarding the real role of wine in headache." In other words, more study is needed.