Study: Green tea extract supplements improve gut health, help lower blood sugar levels

July 27, 2022

Green tea has long been viewed as a healthful drink—and now, an Ohio State University study has demonstrated that four-week green tea extract consumption can improve gut health and reduce blood sugar levels by decreasing inflammation, reports Gut News.

The research team conducted this work to build off a 2019 study that established that fewer health risks and incidences of  obesity  are associated with consumption of green tea.

“There is much evidence that greater consumption of green tea is associated with good levels of cholesterol, glucose, and triglycerides, but no studies have linked its  benefits to the gut  to those health factors,” says Richard Bruno, senior study author and professor of Human Nutrition at the school.

This latest clinical trial included 40 adults—21 with metabolic syndrome; and 19, healthy. They consumed gummy green tea extract supplements for 28 days daily. The dosage equates to five cups of tea. In the randomized double-blind crossover trial, all participants consumed a placebo for an additional 28 days, taking a month off entirely between treatments.

Researchers also advised participants to follow a diet low in polyphenols, which are antioxidants found naturally in fruits, vegetables, teas, and spices. This is so that during the placebo and green tea extract supplement phases, the results could be attributed to just the green tea and not anything confounding.

Results show that fasting blood glucose levels in all participants were significantly lower after taking the green tea extract supplement compared to post-placebo.

Also, upon analysis of fecal samples, a reduction in pro-inflammatory proteins was see in all participants—meaning that the gut saw a significant decrease in inflammation.

Further, the team used a technique to assess sugar ratios in urine samples. Findings show participants’ small intestine permeability decreased after the green tea consumption, meaning that  leaky gut syndrome  conditions were alleviated.

“That absorption of gut-derived products is thought to be an initiating factor for obesity and  insulin resistance, which are central to all cardiometabolic disorders,” Bruno notes. “If we can improve gut integrity and reduce leaky gut, the thought is we’ll be able to not only alleviate low-grade inflammation that initiates cardiometabolic disorders, but potentially reverse them.”

Metabolic syndrome wasn’t cured over the month, but the study does show that green tea has lots of potential to notably lessen the risk for developing the condition and even reversing it, due to its supportive effects on the gut. Bruno’s lab is confident that their team produced findings that will positively impact chronic conditions through gut health. They plan to continue analyzing the gut microbiome, identifying any toxins that can increase susceptibility to poor health.

This study is published in the journal, Current Developments in Nutrition.

For those who are interested in trying green tea extract, a high dosage is considered to range from 10 to 29 milligrams per kilogram (or 4.54 to 13.15 milligrams per pound) of body weight per day.

And experts warn enthusiasts no to overdo it. The National Institute of Health  says green tea extract supplements have been linked to several cases of liver damage and can accelerate liver disease.

Research contact: @gutnews