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This Key Ingredient in Red Wine May Help Weaken COVID-19 Symptoms, Study Suggests

But there's a catch. We asked an infectious disease doctor to clarify.

There are few things as satisfying as popping open a bottle of red wine and enjoying a glass (well, maybe two) at the end of a long workday. When enjoyed in moderation, this alcoholic beverage also offers a host of health benefits. Now, new research suggests that tannic acid, which is found in plants such as grape skins, may help suppress COVID-19.

Published in the American Journal of Cancer Research, the study was led by a team of researchers at China Medical University in Taiwan. What exactly did they uncover? Tannic acid, which belongs to the tannin family, may help stop the replication of SARS-CoV-2, which is the virus that causes COVID-19. (Present in red wine, tannins impact the richness of texture.)

The team studied tannic acid and five other natural compounds to see how successful they were at suppressing viral activity. As it turned out, tannic acid was the most effective of the bunch. (Related: The 7 Healthiest Foods to Eat Right Now)

"Among the six compounds tested, only tannic acid showed significant activity of inhibiting up to 90% of the enzymatic activity of SARS-CoV-2," the study reports.

For context, in order for the SARS-CoV-2 virus to hijack human cells, its key protease (enzyme) known as Mpro must lock into a receptor in the human cell membrane so that it can replicate and spread. Another study yielded similar findings, revealing that certain chemical compounds in dark chocolate, green tea, and muscadine grapes can potentially inhibit Mpro's function.

However, before you go to a liquor store to stock up on bottles of red wine or a grocery store to clear all of the dark chocolate bars off the shelves, it's important to note one key flaw in each of these studies. The findings only reflect what was found in a petri dish.

"Things that happen in a cell culture don't necessarily translate into a demonstrable human impact," Noreen Hynes, MD, MPH, and director of the Geographic Medicine Center of the Division of Infectious Diseases at Johns Hopkins Medicine, says. "We don't have any evidence that people who drink red wine are less susceptible to the virus."

Hynes—who runs inpatient clinical trials for COVID-19—also points out that the study doesn't tell us how much red wine would even be needed to have this effect on enzymatic activity. In fact, the amount of red wine that could be required may be toxic to humans. This is why preclinical studies (typically done on laboratory animals) are needed to evaluate safety.

"I do think it's very important that people remember the recommendation for wine is that men drink no more than two glasses a day and that women drink one," Hynes adds.

She also points out that red wine isn't the only thing that's rich in tannins. Cranberries, for example, also provide a good source of tannins, as do both black and green teas.

Ultimately, more research and human clinical trials are needed to see if red wine could stop the spread of COVID-19 in the body. Right now, the best thing you can do is keep your immune system strong by eating healthy, exercising, and getting plenty of rest. For more, don't miss the 7 Best Teas to Support Your Immune System Right Now!

Cheyenne Buckingham
Cheyenne Buckingham is the former news editor of Eat This, Not That! Read more about Cheyenne