Green tea polyphenol EGCG counteracts obesity and cognitive decline caused by Western diet

30-Jul-2017 - Last updated on 31-Jul-2017 at 15:08 GMT

Green tea is the second most consumed beverage in the world after water. ©iStock

There is "compelling evidence" that EGCG from green tea could improve memory impairment, brain insulin resistance, and obesity caused by a high-fat and high-fructose diet, researchers have claimed.

A study on mice that was published online in The FASEB Journal suggests that EGCG (epigallocatechin-3-gallate), the most abundant catechin and biologically active component in green tea, can counteract insulin resistance and some of the cognitive deficits triggered by a Western diet.

"EGCG, the major polyphenol in green tea, possesses antioxidant, anti-inflammatory, and cardioprotective activities; however, few reports have focused on its potential effect on cognitive disorders. In this study, our goal was to investigate the protective effects of EGCG treatment on insulin resistance and memory impairment induced by a high-fat and high-fructose diet (HFFD)," wrote academics at the College of Food Science and Engineering, Northwest A&F University, in Yangling, China.

"To our knowledge, this study is the first to provide compelling evidence that the nutritional compound EGCG has the potential to ameliorate HFFD-triggered learning and memory loss."

16-week assessment

For the study, the mice were divided into three groups: a control group fed a standard diet, a group fed a HFFD, and a group fed with a HFFD and 2g of EGCG per litre of drinking water.

Researchers monitored the mice for 16 weeks and found that those fed with HFFD had a higher final body weight than the control mice, and a significantly higher final body weight than the HFFD+EGCG mice.

In performing a Morris water maze test, researchers found that mice in the HFFD group took longer to find the platform compared to mice in the control group. The HFFD+EGCG group had a significantly lower escape latency and escape distance than the HFFD group on each test day.

When the hidden platform was removed to perform a probe trial, HFFD-treated mice spent less time in the target quadrant when compared with control mice, with fewer platform crossings.

The HFFD+EGCG group also exhibited a significant increase in the average time spent in the target quadrant and had greater numbers of platform crossings, showing that EGCG could improve HFFD-induced memory impairment.

"Green tea is the second most consumed beverage in the world after water, and is grown in at least 30 countries," said researcher Xuebo Liu."The ancient habit of drinking green tea may be a more acceptable alternative to medicine when it comes to combating obesity, insulin resistance, and memory impairment."

Source: The FASEB Journal

doi:10.1096/fj.201700400RR

"EGCG ameliorates high-fat- and high-fructose-induced cognitive defects by regulating the IRS/AKT and ERK/CREB/BDNF"

Authors: Xuebo Liu, et al.