Green tea extract lowers blood sugar and improves gut health

Consuming green tea extract for four weeks can reduce blood sugar levels and improve gut health. New research focused on individuals with a risk of heart disease found that green tea extract can lower inflammation and decrease “leaky gut.”

This is the first study to assess whether health risks linked to metabolic syndrome could be diminished by green tea’s anti-inflammatory benefits in the gut Metabolic syndrome affects up to one-third of adults in the U.S. This is the first study to assess whether health risks linked to metabolic syndrome could be diminished by green tea’s anti-inflammatory benefits in the gut.

Study senior author Richard Bruno is a professor of Human Nutrition at The Ohio State University.

“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 at the gut to those health factors,” said Bruno.

The clinical trial was conducted on 40 individuals as a follow-up to a 2019 study that associated lower obesity and fewer health risks in mice that consumed green tea supplements.

In the current study, the researchers made an unexpected discovery. They found that green tea extract lowers blood sugar and decreases gut inflammation and permeability in healthy people.

“What this tells us is that within one month we’re able to lower blood glucose in both people with metabolic syndrome and healthy people, and the lowering of blood glucose appears to be related to decreasing leaky gut and decreasing gut inflammation – regardless of health status,” Bruno said.

People with metabolic syndrome are diagnosed with at least three of five factors that increase the risk for heart disease,and other health problems – excess belly fat, high blood pressure, low good cholesterol, and high levels of fasting blood glucose and triglycerides, a type of fat in the blood.

These risk factors are often only slightly altered as physicians commonly recommend weight loss and exercise. But overall lifestyle modifications can be difficult for some people, and these risk factors can continue to threaten overall health.

“Our work is aiming to give people a new food-based tool to help manage their risk for metabolic syndrome or to reverse metabolic syndrome.” said Bruno.

For 28 days, participants consumed gummy confections containing green tea extract rich in anti-inflammatory compounds called catechins. The daily dose equaled five cups of green tea. All participants spent another 28 days taking a placebo, with a month off of any supplement between the treatments.

The participants followed a diet low in naturally occurring antioxidants in fruits, vegetables, teas and spices during the placebo and green tea extract periods to ensure that results could be attributed to the effects of green tea alone.

The results showed that fasting blood glucose levels for all participants were significantly lower after taking green tea extract compared to levels after taking the placebo. The experts found that all participants had decreased gut inflammation and a decrease in small intestine permeability.

Gut permeability, or leaky gut, enables intestinal bacteria and related toxins to enter the bloodstream, stimulating low-grade chronic inflammation.

“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,” said Bruno. “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.”

The researchers believe there is potential for green tea to alleviate the risk of either developing or reversing metabolic syndrome.

The research was supported by the U.S. Department of Agriculture and the Ohio Agricultural Research and Development Center at Ohio State. The findings are published in the journal Current Developments in Nutrition.

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By Katherine Bucko, Earth.com Staff Writer