You have probably heard it a hundred times. A glass of red wine with dinner is supposedly good for your heart. For decades, that nightly pour has carried an almost medicinal aura in popular wellness.
The problem starts with the dose. The health claim leans heavily on resveratrol, a plant compound in grape skins. In red wine, resveratrol sits at roughly 0.1 to 7 milligrams per liter, according to a review of the evidence published in the journal Molecules.
That is a very small amount. Lab studies on resveratrol typically use far higher doses.
To reach the commonly cited therapeutic dose of about 1 gram a day, a person would need to drink more than 500 liters of red wine, according to the European Food Information Council. That is more than most people drink in a lifetime.
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Where the heart story actually came from
Much of the belief traces back to observational studies, most famously the French paradox. Researchers noticed that people in France had lower rates of coronary heart disease than other Western populations despite a diet heavy in cheese and butter.
Red wine looked like a plausible explanation. The problem is that observational studies have a well-known limit. They can show that two things appear together, but they cannot prove that one causes the other.
People who drink wine in moderation tend to earn more, eat more vegetables, exercise more and smoke less. Any of those factors could be doing the work the wine gets credit for.
Any potential heart benefits from red wine are small, scientifically uncertain, and mainly based on observational studies, the European Food Information Council writes.
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The polyphenols are not unique to wine
Resveratrol belongs to a wider family of polyphenols, the plant compounds thought to be behind most of the heart story.
Red wine does contain more polyphenols than white wine, but it contains less than dark chocolate or blueberries, according to the Harvard T.H. Chan School of Public Health.
Eric Rimm is a professor at Harvard T.H. Chan School of Public Health who has studied alcohol and health for three decades. He has pointed out that there is no conclusive science showing a real benefit of red wine over white.
Berries, grapes, nuts, cocoa and green tea deliver similar plant compounds without any alcohol attached.
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The cancer side of the ledger
While the heart benefit is uncertain, the cancer risk is not. The International Agency for Research on Cancer classifies alcohol as a Group 1 carcinogen, the same category as tobacco and asbestos.
The European Food Information Council states that alcohol is classified as a carcinogen because there is strong evidence that it causes cancer no matter how small or rare the exposure.
The risk applies to cancers of the oral cavity, throat, esophagus, liver, colon and female breast.
What the authorities actually recommend
Major health bodies do not recommend drinking red wine for your heart. The European Food Information Council states plainly that red wine should not be considered a health strategy, and starting to drink for health reasons is not recommended.
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Carla Cos is a registered dietitian at UT Dell Medical School's Primary Care Clinic. She has stressed to UT Dell Medicine that research has not shown a cause-and-effect link between moderate red wine and better heart markers, only an association.
For anyone drawn by the polyphenols, a handful of berries, a square of dark chocolate or a cup of green tea delivers the same plant compounds without the alcohol attached.
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This article is made and published by Mie Hermansen, who may have used AI in the preparation.