Is red wine really good for your gut?

A new study by researchers at Kings College London has found that red wine could prevent obesity and lower cholesterol, but how much do you need to drink?

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A team of scientists have published a study in the journal Gastroenterology claiming that, compared to beer and spirits, red wine is the healthiest for your gut, while drinking red wine “rarely” could help to lower cholesterol and keep obesity at bay.

Researchers at Kings College London explored the effect of beer, cider, red wine, white wine and spirits on the gut microbiome (GM) and subsequent health in a group of 916 female twins in the UK.

The microbiome is the collection of microorganisms in a particular environment.

An imbalance of ‘good’ microbes compared to ‘bad’ in the gut can lead to adverse health outcomes such as reduced immune system, weight gain or high cholesterol. A person’s gut microbiome with a higher number of different bacterial species is considered a marker of gut health.

They found that the GM of red wine drinkers was more diverse compared to non-red wine drinkers, but the same diversity was not seen in those who drank white wine, beer or spirits consumption.

While there have been many studies published controversially linking red wine to good heart health, the new findings show that moderate red wine consumption could be linked to greater diversity and healthier gut microbiota, which in-turn goes some way to explaining the “long debated beneficial effects” red wine has on our health, according to Dr Caroline Le Roy, the first author of the study.

The same results were observed in three different test groups in the UK, the U.S. And the Netherlands. The authors said they also took into account factors such as age, weight, the regular diet and socioeconomic status of the participants and continued to see the association.

“This is one of the largest ever studies to explore the effects of red wine in the guts,” Professor Tim Spector, the lead author of the study, said.

The researchers believe the reason for the association is due to the levels of polyphenols in red wine. Polyphenols, such as antioxidants, are defence chemicals naturally present in many fruits and vegetables.

Implying that alcohol has health benefits obviously has ethical implications, but Spector said this study shows that the high levels of polyphenols in the grape skins “could be responsible for much of the controversial health benefits when used in moderation.”

The study also found that red wine consumption was associated with lower levels of obesity and ‘bad’ cholesterol which was in part due to the gut microbiota.

Le Roy added that, if you must choose one alcoholic drink red wine is the one to go for, as it seems to have “a beneficial effect on you and your gut microbes, which in turn may also help weight and risk of heart disease.”

The debate over red wine’s potential health benefits spans a wide range of areas. It has been linked to  preventing cancer, warding off diabetes, and even to better mental health, thanks to the presence of some compounds in red grape skins such as polyphenols and resveratrol.

Present in the skin and seeds of red grapes, the chemical compound resveratrol is associated with a number of health benefits and is even being considered as a supplement to keep astronauts fit in space.

However, it would be an oversimplification to say that red wine is inherently good for you.

The NHS’ recommended weekly intake of alcohol is 14 units. A large (250 ml) glass of 12% ABV red wine has about three units of alcohol. A medium (175 ml) glass has about two units. A large glass can contain around 228 calories, according to Drinkaware, about the same as a piece of cake.

Le Roy added that they found that test subjects who were “drinking red wine rarely, such as once every two weeks,” were drinking enough to have a positive effect on their gut health.

“It is still advised to consume alcohol with moderation,” she said.

The TwinsUK microbiota project was funded by the National Institute of Health.