Tag Archives: Black tea

Daily 4 cups of black or green or Oolong tea can cut diabetes risk by 17%

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Sep 18 (IANS) A moderate consumption of black, green or Oolong (traditional Chinese drink) tea is linked to a lower risk of developing type 2 diabetes, a study involving over a million adults from eight countries has revealed.

The findings suggest that drinking at least four cups of tea a day is associated with a 17 per cent lower risk of diabetes over an average period of 10 years.

“Our results are exciting because they suggest that people can do something as simple as drinking four cups of tea a day to potentially lessen their risk of developing type 2 diabetes”, said lead author Xiaying Li from Wuhan University of Science and Technology in China.

benefits of green tea

benefits of green tea/Ians

The study, to be presented at the European Association for the Study of Diabetes (EASD) annual meeting in Sweden next week, scanned 19 cohort studies.

While it’s long been known that regularly drinking tea may be beneficial for health because of the various antioxidant, anti-inflammatory and anti-carcinogenic compounds tea contains, less clear has been the relationship between tea drinking and the risk of diabetes.

Overall, the new meta-analysis found a linear association between tea drinking and diabetes risk, with each cup of tea consumed per day reducing the risk of developing diabetes by around 1 per cent, said the study published in peer-reviewed journal Diabetologia.

When compared with adults who didn’t drink tea, those who drank 1-3 cups daily lowered their risk of diabetes by 4 per cent, while those who consumed at least 4 cups every day reduced their risk by 17 per cent.

The associations were observed regardless of the type of tea participants drank, whether they were male or female, or where they lived, suggesting that it may be the amount of tea consumed, rather than any other factor, that plays a major role.

“While more research needs to be done to determine the exact dosage and mechanisms behind these observations, our findings suggest that drinking tea is beneficial in reducing the risk of type 2 diabetes, but only at high doses (at least 4 cups a day)”, said Li.

It is possible that particular components in tea, such as polyphenols, may reduce blood glucose levels, but a sufficient amount of these bioactive compounds may be needed to be effective.

Despite the important findings, the authors noted that the study is observational and cannot prove that drinking tea reduces the risk of diabetes, but suggests that it is likely to contribute.

Black tea may help with weight loss, too

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UCLA researchers have demonstrated for the first time that black tea may promote weight loss and other health benefits by changing bacteria in the gut. In a study of mice, the scientists showed that black tea alters energy metabolism in the liver by changing gut metabolites.

The research is published in the European Journal of Nutrition.

The study found that both black and green tea changed the ratio of intestinal bacteria in the animals: The percentage of bacteria associated with obesity decreased, while bacteria associated with lean body mass increased.

Previous studies indicated that chemicals in green tea called polyphenols are absorbed and alter the energy metabolism in the liver. The new findings show that black tea polyphenols, which are too large to be absorbed in the small intestine, stimulate the growth of gut bacterium and the formation of short-chain fatty acids, a type of bacterial metabolites that has been shown to alter the energy metabolism in the liver.

“It was known that green tea polyphenols are more effective and offer more health benefits than black tea polyphenols since green tea chemicals are absorbed into the blood and tissue,” said Susanne Henning, the study’s lead author and an adjunct professor at the UCLA Center for Human Nutrition, which is part of the David Geffen School of Medicine at UCLA. “Our new findings suggest that black tea, through a specific mechanism through the gut microbiome, may also contribute to good health and weight loss in humans.”

“The results suggest that both green and black teas are prebiotics, substances that induce the growth of good microorganisms that contribute to a person’s well-being,” she said.

In the study, four groups of mice received different diets — two of which were supplemented with green tea or black tea extracts:

Low-fat, high-sugar
High-fat, high-sugar

High-fat, high-sugar and green tea extract

High-fat, high-sugar and black tea extract

After four weeks, the weights of the mice that were given green or black tea extracts dropped to the same levels as those of the mice that received the low-fat diet throughout the study.

The researchers also collected samples from the mice’s large intestines (to measure bacteria content) and liver tissues (to measure fat deposits). In the mice that consumed either type of tea extract, there was less of the type of bacteria associated with obesity and more of the bacteria associated with lean body mass.

However, only the mice that consumed black tea extract had an increase in a type of bacteria called Pseudobutyrivibrio, which could help explain the difference between how black tea and green tea change energy metabolism.

Dr. Zhaoping Li, director of the UCLA Center for Human Nutrition, chief of the UCLA Division of Clinical Nutrition and the study’s senior author, said the findings suggest that the health benefits of both green tea and black tea go beyond their antioxidant benefits, and that both teas have a strong impact on the gut microbiome.

“For black tea lovers, there may be a new reason to keep drinking it,” she said.

The findings build on a 2015 UCLA study that demonstrated that both green tea and black tea helped prevent obesity in mice that consumed a high-fat, high-sugar diet.