Tea Consumption Reduces Cardiovascular Disease Risk

by | Jan 27, 2020 | 2020, Cardiovascular Health, Flavonoids

Written by Joyce Smith, BS. This study demonstrates that habitual consumption of green tea is associated with better health and improved life expectancy.  

teaCardiovascular disease (CVD) is the leading cause of premature death worldwide 1. In 2017, CVD was responsible for 4.4 million deaths (40% of all deaths). The high mortality rate of  coronary heart disease (CHD) and stroke in China 2, has spiked research into the health benefits of tea, considered one of the most popular Asian beverages for its potential atherosclerotic cardiovascular disease (ASCVD) benefits.  Green tea, in particular, is a rich source of bioactive flavonoids, including epicatechin, catechin, andepigallocatechin-3-gallate (EGCG), that could reduce inflammation and oxidative stress 3, improve heart function 4, and reduce CVD risk factors such as hypertension and dyslipidemia 5,6.  Several previous studies have found an association between tea consumption and CVD and all-cause mortality but results have been inconsistent 7.

Researchers Gu and team 8 analyzed the association of tea drinking habits of three cohorts (100,902 participants) from the project of Prediction for ASCVD Risk in China (China-PAR). They were classified into the following groups: habitual tea drinkers who drank tea three or more times per week, nonhabitual tea drinkers who drank tea less than three times per week, and never tea drinkers who became the reference group. The influence of behavior changes in tea drinkers was assessed among participants at baseline and again in two follow-up surveys (2007-2008 and 2012-2015) in the InterASIA and the China Mucca (1998) cohorts for a median of 7.3 years.

Overall, 31.6% of all participants (48.2% men and 20.4% women) drank tea three or more times/week at baseline. Of these habitual tea drinkers 49.0% consumed green tea most frequently, 8.0% preferred black tea, and the remaining 43.0% preferred scented tea or other types. Habitual tea drinkers were more likely to be men, smokers and alcohol drinkers.

Collective analysis showed that habitual tea drinking was associated with a lower risk of ASCVD (including CHD and stroke), ASCVD mortality (especially for stroke), and all-cause mortality and these inverse associations were not only persistent across subgroups but were stronger for those who maintained their tea drinking habit throughout the entire follow-up period.  In fact, those who habitually drank tea, could potentially delay the development of ASCVD and stroke by 1.41 years or live a potential 1.26 years longer than those who never or seldom drank tea.

Both surveys revealed a 39% lower risk of incident heart disease and stroke, a 56 % lower risk of fatal heart disease and stroke, and a 29% decreased risk of all-cause death compared to non-habitual tea drinkers or those who never drank tea. The authors note that habitual tea drinking was more protective against stroke for men than women. (For women, results for stroke incidence failed to reach statistical significance). They suggest that the protective effects of tea could be increased by lowering high blood pressure 9 since hypertension contributes greatly to the high incidence of stroke in China 10. Also habitual tea consumption was higher among men then among women which might explain its greater protective effect for men. Data also revealed a much lower incidence and mortality of ASCVD for women; however, this advantage could be lost after menopause.

In a sub analysis of tea type, green tea drinking was linked with approximately 25% lower risks of incident heart disease and stroke, fatal heart disease and stroke, and all-cause death. No associations were found for black tea which could be explained by the fact that in this study population, 49% of habitual tea drinkers consumed green tea most frequently while only 8% were black tea drinkers.

Limitations: This is a prospective cohort study that can only establish an association – not causation; however, it does build on and strengthen the body of evidence that habitual tea drinking is associated with reduced rates of ASCD. Additional randomized, placebo controlled trials to validate these findings are recommended.

Source: Wang, Xinyan, Fangchao Liu, Jianxin Li, Xueli Yang, Jichun Chen, Jie Cao, Xigui Wu et al. “Tea consumption and the risk of atherosclerotic cardiovascular disease and all-cause mortality: The China-PAR project.” European journal of preventive cardiology (2020): 2047487319894685.

© The European Society of Cardiology 2020

Posted January 27, 2020.

Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from  the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.

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