Tea instead of "medicine"? 4 cups of tea a day can significantly reduce the risk of diabetes! 2022 EASD

Introduction: The key to drinking tea to prevent diabetes is to "have enough amount"
.

Type 2 diabetes mellitus (T2D) has become one of the major disease burdens worldwide, and understanding the correlation between different diets and T2D risk is key
to optimizing dietary choices and preventing disease, given that dietary habits are closely related to the occurrence and development of T2D.
A study of more than 1 million adults, presented at the 58th annual meeting of the European Association for the Study of Diabetes in Stockholm, Sweden, found that at least 4 cups of tea per day may significantly reduce the risk
of T2D over 10 years.
This academic achievement comes from the research team
of Wuhan University of Science and Technology in China.

Drinking tea is good for health

While it has long been known that regular tea drinking may have health benefits because tea contains a variety of antioxidant, anti-inflammatory, and anti-cancer compounds, the relationship between tea drinking and T2D risk is less clear
.
To date, the results of published cohort studies and meta-analyses have been inconsistent
.
To this end, the researchers conducted a cohort study and dose-response meta-analysis to better define the relationship between
tea drinking and future T2DM risk.

The investigators recruited 5199 adults (2583 males, 2616 females) with no history of T2D (mean age 42 years) from the 1997 China Health and Nutrition Survey (CHNS) and followed them until 2009
.
Participants filled out a questionnaire on dietary frequency and provided lifestyle information, such as whether they exercised regularly, smoked and consumed alcohol
.
Overall, 2379 (46%) participants reported a tea drinking habit, and by the end of the study, 522 (10%) participants had developed T2D
.

Initially, after adjusting for factors known to be associated with an increased T2D risk, such as age, sex, and lack of exercise, the researchers did not find a correlation between tea drinking and T2D risk compared to those who did not drink tea, including analysis of age and sex, and exclusion of participants who developed diabetes during the first 3 years of follow-up
.

"Quantity" is key: at least four cups of tea per day reduces diabetes risk by 17%!

In the next step of the study, researchers conducted a systematic review of all cohort studies investigating tea drinking and T2D risk in adults (18 years of age or older) up to September 2021, including 19 cohort studies involving 1,076,311 participants
from eight countries.

The potential effects
of different types of tea (green, oolong and black), frequency of tea consumption (less than 1 cup per day, 1-3 cups per day, and 4 or more cups per day), gender (men and women), and study location (Europe, America or Asia) on T2D risk were explored.

Overall, the meta-analysis found a linear association between tea drinking and T2D risk, compared to adults who did not drink tea:

➤ Each cup of tea drunk daily can reduce the risk of T2D by about 1%;

➤ People who drank 1-3 cups of tea per day had a 4% lower risk of T2D;

People who drank at least 4 cups of tea a day had a 17%
lower risk of T2D.

Green tea, black tea, oolong tea, how to choose?

Regardless of which tea participants drank, regardless of other factors such as gender, the above benefits were observed, suggesting that the amount of tea consumed may have played a major role
.

While more research needs to be done to determine the exact dosage and mechanism behind these observations, the findings suggest that drinking tea can help reduce the risk of T2D, but only with high intake (at least 4 cups per day).

Special ingredients in tea, such as polyphenols, may lower blood sugar levels, but it may take sufficient amounts of these bioactive compounds to be effective
.
This may also explain why no link between tea drinking and T2D was found in cohort studies, as higher tea
consumption was not observed.

Summary of this article

Overall, this systematic review and meta-analysis of 19 studies of a cohort of more than 1 million adults in eight countries found that moderate consumption of black, green or oolong tea was associated with a reduced risk of T2D, with tea consumption being key, recommended at least 4 cups
per day.