Does Green Tea Improve Cognition?


Brew up a batch of green tea and you may be doing your mind a big favor. A new animal study suggests that the active ingredients in green tea can boost cognitive power.

The study, conducted by researchers at Northwest A&F University in Yangling, China, puts a close scope on the average Western diet and offers yet another health-promoting reason to add some steeped tea leaves to your daily regimen.

Credit: Kanko/Flickr, CC BY 2.0

Specifically, the researchers assessed how the most active components of green tea — known as catechins — might influence health outcomes on mice that showed signs of insulin resistance due to a high-fructose diet. Knowing that insulin resistance also leads to other harmful outcomes, the researchers speculated that improving insulin activity might have a positive downstream effect.

“Obesity increases the risk of insulin resistance and age-related cognitive decline, accompanied by peripheral inflammation,” report the study authors in The FASEB Journal.

For the study, the researchers assessed a component of green tea called epigallocatechin-3-gallate (EGCG), the most plentiful catechin contained in the tea leaves. They divided three-month old mice into three separate groups — one was fed a diet rich in high-fructose; another was given a high-fructose diet along with two grams of EGCG; and a third maintained a regular diet.

After about four months, the researchers discovered, perhaps unsurprisingly, that the mice fed a high-fructose diet had more body mass than the mice on a control diet. But they also found that mice on only a high-fructose diet had “a significantly higher final body weight” than the mice whose high-fructose diet was supplemented with the green tea catechins.

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The results extended to cognitive power, too. The researchers had the three groups of mice undergo a Morris water maze test to assess their mental acuity. On every measure of the test, the high-fructose-only group performed worse than the mice that also consumed the EGCG supplements.

The study adds compelling evidence to support the overall benefits of green tea consumption, while finding even more reason to brew a batch.

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,” report the study authors.

“To our knowledge, this study is the first to provide compelling evidence that the nutritional compound EGCG has the potential to ameliorate [high-fructose]-triggered learning and memory loss,” the researchers add.

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Already, billions of people may be reaping the cognitive benefits of green tea.

“Green tea is the second most consumed beverage in the world after water, and is grown in at least 30 countries,” said Xuebo Liu, Ph.D., a researcher at the College of Food Science and Engineering at Northwest A&F University.

“The ancient habit of drinking green tea may be a more acceptable alternative to medicine when it comes to combatting obesity, insulin resistance, and memory impairment,” added Liu.

Previously, studies have linked drinking green tea to lowering the risk of heart disease, protecting against cancer, promoting weight loss and improving one’s mood and concentration.