Tea is traditionally consumed as a beverage. Evidence from clinical trials suggests that green tea plays a role in metabolic syndrome because it may have an impact on body weight, glucose homeostasis, and other cardiovascular risk factors.
Epidemiology studies from other countries have related tea consumption to lower risks of cardiovascular diseases and all-cause mortality. However, the study’s conclusions remain inconsistent.
A new study by the European Society of Cardiology aimed to systematically examine the associations between tea consumption and the risk of atherosclerotic cardiovascular disease and all-cause mortality. The results were surprising.
Scientists found that consumption of green tea thrice a week is linked with longer and healthier life. The study is published in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC).
The study included 100,902 general Chinese adults from the project of Prediction for ASCVD Risk in China (China-PAR) in 15 provinces across China since 1998. The participants did not have a history of heart attack, stroke, or cancer and followed up for a median of 7.3 years.
They were then categorized into two groups: habitual tea drinkers (three or more times a week) and never or non-habitual tea drinkers (less than three times a week).
Habitual tea consumption was associated with more healthy years of life and longer life expectancy.
For example, the analyses estimated that 50-year-old habitual tea drinkers would develop coronary heart disease and stroke 1.41 years later and live 1.26 years longer than those who never or seldom drank tea.
Compared with never or non-habitual tea drinkers, habitual tea consumers had a 20% lower risk of incident heart disease and stroke, 22% lower risk of fatal heart disease and stroke, and 15% decreased risk of all-cause death.
Habitual tea drinkers who maintained their habit in both surveys had a 39% lower risk of incident heart disease and stroke, 56% lower risk of fatal heart disease and stroke, and 29% decreased risk of all-cause death compared to consistent never or non-habitual tea drinkers.
Senior author Dr. Dongfeng Gu, Chinese Academy of Medical Sciences, said: “The protective effects of tea were most pronounced among the consistent habitual tea drinking group. Mechanism studies have suggested that the main bioactive compounds in tea, namely polyphenols, are not stored in the body long-term. Thus, frequent tea intake over an extended period may be necessary for the cardioprotective effect.”
Drinking green tea was linked with approximately 25% lower risks for incident heart disease and stroke, fatal heart disease and stroke, and all-cause death. However, no significant associations were observed for black tea.
The authors concluded that randomized trials are warranted to confirm the findings and provide evidence for dietary guidelines and lifestyle recommendations.