Regular tea drinkers—especially those who favor green tea over black—lived longer and developed CVD later than non-habitual tea drinkers in a recent study of more than 100,000 people in China.
The study, headed by Xinyan Wang of the Chinese Academy of Medical Sciences in Beijing and published Jan. 8 in the European Journal of Preventive Cardiology, explored the relationship between heart health and tea consumption in 100,902 individuals enrolled in the China-PAR project. Participants were considered habitual tea drinkers if they brewed a cup at least three times a week; others were considered never or non-habitual consumers.
Wang and her team followed China-PAR enrollees for an average of 7.3 years and found that, compared with never or non-habitual tea drinkers, regular tea drinkers saw a 20% lower risk of incident heart disease and stroke, a 22% decreased risk of fatal heart disease and stroke and a 15% lower risk of all-cause death. In other words, a 50-year-old who regularly drinks tea would develop coronary heart disease 1.41 years later and live 1.26 years longer than their non-tea-drinking counterparts.
The researchers studied the potential influence of changes in tea drinking behavior in a subset of 14,081 individuals who were surveyed in two polls eight years apart. Habitual tea drinkers who maintained the habit in both surveys experienced a 39% lower risk of incident heart disease and stroke, 56% lower risk of fatal heart disease and stroke and 29% lower risk of all-cause death than those who weren’t regular consumers.
“The protective effects of tea were most pronounced among the consistent habitual tea drinking group,” Dongfeng Gu, senior author of the study, said in a release. “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.”
Green tea proved more useful for CV health than black tea—a finding the authors attributed to the fact that while green tea is rich with polyphenols that protect against CVD, high blood pressure and dyslipidemia, black tea is fully fermented and often served with milk. Gu said the team’s study population largely preferred green tea (the preference of 49% of habitual tea drinkers) to black tea (the preference of 8% of habitual drinkers).
The authors also reported that their findings were more robust for men than for women.
“One reason might be that 48% of men were habitual tea consumers compared to just 20% of women,” Wang said in the release. “Secondly, women had much lower incidence of, and mortality from, heart disease and stroke. These differences made it more likely to find statistically significant results among men.”
The China-PAR study is reportedly ongoing, with more person-years of follow-up planned.