Dr. Roach: Is it the alcohol or grapes that give wine a good-for-you rep?

Keith Roach
To Your Health

Dear Dr. Roach: Alcoholism runs in my family. I do not drink. For years I’ve read studies showing how good a glass of red wine is for you. Just recently something came out on the local news that “wine is good for your gut.”

On a far less frequent basis, news appears that grape juice is also good for you. Is it the alcohol that makes wine good for your health, or the grapes? Many people cannot control their desire for alcohol, which is a mind-altering substance that can wreak havoc on marriages and the highway, just to name two. Can you clarify whether it’s wine or grape juice that’s good for your health?

— H.J.H.

Dear H.J.H.: The common wisdom that a glass of wine a day is good for you is unproven. It is certainly true that people who drink moderately tend to be very healthy, but it is not clear that it’s the wine drinking that causes the benefit. People who drink moderately tend to have many other healthy behaviors, and despite great efforts on the part of researchers, it is not possible with the current evidence to be sure if moderate alcohol is really of benefit.

On the other hand, it is abundantly clear that moderate to heavy drinking is extraordinarily dangerous, and I would add liver disease and many cancers to your short list of the dangers of excess alcohol consumption. There is some evidence that even modest drinking increases risk of dementia.

Grape skins contain quantities of several natural compounds that are purported to have benefit to the body. Since only red wine uses the skins of the grapes, red wine has long been considered the best for health reasons. However, epidemiological evidence suggests that modest drinkers (a standard drink a day or so for men, half a drink for women) have a lower risk of heart disease than nondrinkers, regardless of the type of alcohol they consume. Unfortunately, trials of the individual components of grape skins have not shown a significant benefit.

The “gut health” statement came from a study showing that wine drinkers have a more diverse collection of bacteria in the gut, which is an accepted measure of gut health. Interestingly, even people who consume wine only every two weeks had this positive association, while people who drank other types of alcohol did not. This type of study cannot determine whether the wine consumption caused this beneficial bacteria diversity, nor whether this diversity leads to better health in the future. It does not answer your question either, as it did not look at people who consumed grapes or grape juice.

Given the uncertainty of benefit of modest alcohol consumption, the known potential for harm of excess consumption (more than two drinks a day from men, more than one for women, or binge drinking in either), I do not recommend consuming red wine or any other kind of alcohol for health benefits. This is even more critical in people who have a family history of problem drinking.

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