A recent study at The Ohio State University where mice were fed a fat-inducing diet showed the inclusion of green tea reduced their fat gain by 20 percent. Those mice also had lower insulin resistance compared to the control group.
While researchers cautioned these results do not automatically translate to the same benefits for humans, their findings have prompted an upcoming study to determine how green tea might affect people with a high risk of diabetes and heart disease.
The study findings published in the Journal of Nutritional Biochemistry pointed to the green tea’s improvement of gut health as the reason for the benefits. The mice had more beneficial microbes in their intestines and less permeability in the intestinal lining. Intestinal permeability is typically referred to as “leaky gut” and contributes to low-grade inflammation throughout the body which is responsible for a host of health problems.
"This study provides evidence that green tea encourages the growth of good gut bacteria, and that leads to a series of benefits that significantly lower the risk of obesity," said Richard Bruno, the study's lead author and a professor of human nutrition at The Ohio State University.
"The results of studies looking at obesity management so far have been a real mixed bag,” Bruno said. “Some seem to support green tea for weight loss, but a lot of other research has shown no effect, likely due to the complexity of the diet relative to a number of lifestyle factors. Our goal is to figure out how it prevents weight gain. This will lead to better health recommendations."
Anti-inflammatory polyphenols called catechins found in green tea have been linked in other studies to anti-cancer activity as well as lower risk for heart and liver disease. Bruno and his colleagues wanted to determine if the anti-inflammatory properties might also help in the fight against obesity.
The mice that consumed green tea had less inflammation in their intestines and fat tissue. The green tea also appeared to protect against the movement of toxic bacteria from the gut into the bloodstream.
The mice had the equivalent of 10 cups of tea for humans which Bruno acknowledged might seem high but is not compared to some parts of the world. He said it may take supplementation to reach the desired amount.