Red Wine Helps Cardiovascular Health, But Is It the Alcohol or Something Else?

Two studies show different results on the source of wine’s heart health benefits

Jacob Gaffney

One of the longest-running debates on the potential health benefits of regular, moderate red wine consumption is whether the alcohol or the other components in wine are responsible for better health. A study from Italy claims that moderate consumption of alcohol, regardless of other compounds like polyphenols, can help prevent a repeat heart attack. But a new study from the U.K. suggests that the polyphenols found in red wine may help keep blood vessels in proper working order.

Previous studies suggest that red wine is responsible for improved blood flow, which helps keep the heart and the body in better health, but whether that’s due to polyphenols or alcohol, or both, is still unclear. A study from the Research Laboratories at the Catholic University of Campobasso, Italy, claims the alcohol, not the antioxidants, helps prevent another heart attack or stroke.

Published in the Journal of the American College of Cardiology, the study looked at 16,351 people from eight countries who had previously suffered a heart-related injury, usually a heart attack. When the researchers compared their drinking habits to the recurrence of strokes, heart attacks, or any other deadly cardiovascular event, they found that moderate drinkers of one to two servings of alcohol per day had a 20 percent lower risk of recurrence compared to nondrinkers and heavier drinkers.

"Our research highlights another crucial issue: Drinking has not only to be moderate, but also regular," said co-author and university epidemiologist Licia Iacoviello in a statement. "Moderate consumption spread along the week is positive. The same amount of weekly alcohol, concentrated in a couple of days, is definitely harmful."

The director of research at Compobasso warned against using the study as an invitation to start drinking, however. In a press release, Giovanni de Gaetano said that the study dealt with previously ill people and, therefore, is not necessarily translatable to the general public.

A study conducted at the University of Surrey, England, published in the Journal of Human Nutrition and Dietetics, suggests that alcohol may not be the only factor, however. A research team found that people who drank a kind of simulated wine—alcohol mixed with red grape juice—during mealtime showed several markers of improved cardiovascular health. Those who drank just water did not see the same levels of improved blood flow. Those who drank just grape juice saw slightly lower benefits.

To try to figure out the relationship between alcohol versus red wine compounds, the team had ten subjects consume a standard meal with a test drink on different occasions. The test drinks accompanying the meal were either water, red grape juice or red grape juice plus alcohol. Red wine itself was not used in any form, as de-alcoholized wine tends to still contain some level of alcohol, which might have marred the results. The simulated wine was red grape juice with alcohol added to create a 12 percent alcohol drink. Various measurements were taken to estimate blood flow.

The flow-mediated dilation, a measure of the ease at which blood is pumped through the body, stood at 6 percent for those who only had water, 7 percent for those who had grape juice only and more than 8 percent for those who had the red grape juice/alcohol mixture.

The scientists credit ingredients in the red grape juice for most of the benefits. "The conclusion drawn from this study was that non-alcoholic components present in alcoholic beverages have a potential benefit on vascular function—blood vessels," said Dr. Shelagh Hampton, senior research fellow on the faculty of Health and Medical Sciences