Study finds green tea extract may improve gut health and glucose levels

New research suggested that green extract had anti-inflammatory benefits to the gut, decreasing leaky gut as well as reducing blood sugar levels in those with metabolic syndrome.

The study, published in Current Developments in Nutrition, was conducted by a team of researchers at Ohio State University (OSU). According to the researchers, while there’s significant evidence linking green tea to healthy levels of cholesterol, glucose, and triglycerides, there’s a lack of research on green tea and its health benefits related to the gut. For this study, researchers sought to understand the effects of green tea extract on gut health as well as the health risks associated with metabolic syndrome.

According to the study, metabolic syndrome refers to a group of conditions that raise the risk of health concerns such as cardiovascular disease, stroke, and diabetes. Those with metabolic syndrome are diagnosed with at least three of five factors that increase these health risks. The five factors include, excess belly fat, high blood pressure, low HDL cholesterol, and high levels of fasting blood glucose and triglycerides.

The clinical trial involved 40 participants and was a follow-up to a 2019 study that found green tea supplements improved gut health, lowered obesity, and reduced health risks in mice. Of the participants, 21 had metabolic syndrome and 19 were deemed healthy adults. Participants spent the first 28 days of the study consuming a gummy that contained green tea extract which was equivalent to five cups of green tea. During the second half of the study, participants took placebo for 28 days. There was a month in between the first and second part of the study. In addition, participants were encouraged to consume diets low in polyphenols, naturally occurring antioxidants found in certain fruits, vegetables teas, and spices.

Researchers tested blood glucose, small intestine permeability through sugar ratios in urine samples, and gut inflammation through analysis of pro-inflammatory proteins in fecal samples after participants took the green tea supplement as well as the placebo.

The study’s results showed that glucose levels among all participants were significantly lower while taking the green tea supplement compared to after they took the placebo. In addition, the green tea supplement was associated with reduced inflammation in the gut and decreased intestine permeability.

According to senior author of the study, Richard Bruno, PhD, RD, professor of human nutrition at OSU, these results give new insight into how green tea can be used to decrease the risks associated with metabolic syndrome through improving gut health.

“We did not attempt to cure metabolic syndrome with a one-month study,” he said. “But based on what we know about the causal factors behind metabolic syndrome, there is potential for green tea to be acting at least in part at the gut level to alleviate the risk for either developing it or reversing it if you already have metabolic syndrome.”