Bottoms up: Habitual wine consumption linked to healthier gut and reduced bad cholesterol

02 Sep 2019 --- Red wine drinkers have an increased gut microbiota diversity and lower levels of obesity and “bad” cholesterol, according to a study from King’s College London, UK. The researchers compared the effects of beer, cider, red wine, white wine and spirits on the gut microbiome and subsequent health in 916 UK female twins. This diversification effect, which was not observed with other drinks, is likely caused by red wine’s many polyphenols. However, the researchers caution that the alcohol must still be consumed responsibly.

“This study shows that when looking at alcohol consumption and health, red wine should be considered separately. The polyphenols likely causing red wine’s benefits are molecules present mostly in the grapes’ skin. They can also be found in many other vegetables or fruits, as well as nuts and seeds and even chocolate. Therefore, drinking red wine is not the only solution to improve our gut microbiota and should still be drunk with moderation,” Caroline Le Roy, Ph.D., first author of the study, tells NutritionInsight.

The study found that the gut microbiota of red wine consumers contained a greater number of different bacterial species compared to non-consumers. Polyphenols are defense chemicals that have various beneficial properties and generally act as a fuel for the microbes in the gut. Additionally, having a high number of different bacterial species is a marker of good gut health. Too many “bad” microbes can lead to health conditions including a reduced immune system, weight gain or high cholesterol.

The study, which has been published in Gastroenterology, found that the gut microbiota of red wine consumers contained a greater number of different bacterial species compared to non-consumers. This result was seen in three different cohorts in the UK, US and the Netherlands, and in spite of factors such as participants’ age, weight, regular diet and socioeconomic status. Additionally, red wine consumption as low as once every other week was associated with lower levels of obesity and “bad” cholesterol, which was in part due to the gut microbiota.

“Studies have consistently shown that low levels of alcohol are protective against heart disease and red wine has been suggested to be particularly important, but any mechanisms were unclear. It is now well recognized that the community of microbes that inhabits our gut plays a key role in our health. This community is partly shaped by what we eat. For example, processed food has a bad effect on its composition, while foods rich in fiber are beneficial for our microbes. However, very little is known about the effect of alcohol consumption on the gut microbiota,” Le Roy explains. 

“One of the main issues in conducting observational studies on alcohol consumption is taking biases into account, such as overall diet, socioeconomic background or genetics. To overcome this issue, our analysis was corrected for these factors. Moreover, we used data collected on twin pairs, where one of the twins was drinking more red wine than their co-twin to account for genetics and some of these environmental biases,” Le Roy continues. 

She notes that researchers have only recently started to understand the importance that the bacterial community present in our gut has on our health. “What is interesting about this community is that unlike our genes, it is possible to change its composition to potentially improve our health. Before we get to that point, we need to understand how we can modify the gut microbiota composition with food.

A recent study found that a high-fat diet can weaken the gut immune system and lead to insulin resistance and, ultimately, diabetes. Other experts in the nutrition industry have also pointed to fermented foods such as kombucha and kefir to being key to boosting gut health. 

“The other driver is personalized nutrition. We all react differently to foods based on our unique gut microbe communities, and this is becoming one of the hottest areas of nutrition,” she highlights. Personalized nutrition has been pegged as one of the top trends in the field, with a recent Lonza-commissioned survey finding that the Millennial generation is largely open to the opportunities that personalization presents to learn more about their bodies. Other experts have also chimed in that we are fully entering an age of personalized nutrition, which will unlock new health avenues around the world. 

By Katherine Durrell