Jan 10, 2020 by Enrico de Lazaro
Using large prospective cohorts among Chinese adults, a research team led by the Chinese Academy of Medical Sciences and Peking Union Medical College has provided new evidence on the protective role of tea consumption on atherosclerotic cardiovascular disease events and all-cause mortality, especially among those who kept the habit all along.
Tea is one of the most popular beverages globally. It is consumed in diverse ways, with brewed tea and products with a tea ingredient extremely prevalent in Asia, especially in China and Japan. It also is more fashionable than ever in Western countries.
It has attracted great attention from both the public and scientists because of its potential benefits, especially for atherosclerotic cardiovascular disease.
Tea, especially green tea, is a rich source of flavonoids including mainly epicatechin, catechin, and epigallocatechin-3-gallate, etc. These bioactive compounds can reduce oxidative stress, relieve inflammation, enhance endothelial and cardiomyocyte function.
“Habitual tea consumption is associated with lower risks of cardiovascular disease and all-cause mortality,” said study first author Dr. Xinyan Wang, a researcher in the Department of Epidemiology at the Chinese Academy of Medical Sciences and Peking Union Medical College.
“The favorable health effects are the most robust for green tea and for long-term habitual tea drinkers.”
In their study, Dr. Wang and colleagues aimed to examine the associations between tea consumption and atherosclerotic cardiovascular disease morbidity and mortality, as well as all-cause mortality among Chinese adults.
They included 100,902 adults from the Prediction for ASCVD Risk in China (China-PAR) project in 15 Chinese provinces since 1998.
Participants were classified 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) and followed-up for a median of 7.3 years. Information on tea consumption was collected through standardized questionnaires.
“Habitual tea consumption was associated with more healthy years of life and longer life expectancy,” the scientists said.
“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 mortality.”
The authors also analyzed the potential influence of changes in tea drinking behavior in a subset of 14,081 participants.
“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 mortality compared to consistent never or non-habitual tea drinkers,” they said.
In an analysis by type of tea, drinking green tea was linked with approximately 25% lower risks for incident heart disease and stroke, fatal heart disease and stroke, and all-cause mortality. However, no significant associations were observed for black tea.
“In our study population, 49% of habitual tea drinkers consumed green tea most frequently, while only 8% preferred black tea,” said study senior author Dr. Dongfeng Gu, also from the Department of Epidemiology at the Chinese Academy of Medical Sciences and Peking Union Medical College.
“The small proportion of habitual black tea drinkers might make it more difficult to observe robust associations, but our findings hint at a differential effect between tea types.”
“Habitual tea consumption could reduce the risk for both atherosclerotic cardiovascular disease morbidity and mortality, as well as all-cause mortality in China, and long-term adherence to the habit could provide with stronger protections,” the scientists concluded.
“Our findings give a further insight into the beneficial role of tea consumption, and have great public health implications for guiding primary prevention among general Chinese adults.”
The findings were published in the European Journal of Preventive Cardiology.