Good news for tea lovers! Researchers have found that drinking tea at least three times a week is linked with longer and healthier life. "Habitual tea consumption is associated with lower risks of cardiovascular disease and all-cause death," said study first author Xinyan Wang, Chinese Academy of Medical Sciences, Beijing in China.
"The favourable health effects are the most robust for green tea and for long-term habitual tea drinkers," Wang added. The analysis, published in the European Journal of Preventive Cardiology, included 1,00,902 participants of the China-PAR project2 with no history of heart attack, stroke, or cancer.
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.
Habitual tea consumption associated with longer life expectancy
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 per cent lower risk of incident heart disease and stroke, 22 per cent lower risk of fatal heart disease and stroke, and 15 per cent decreased risk of all-cause death. The potential influence of changes in tea drinking behaviour were analysed in a subset of 14,081 participants with assessments at two time points.
The average duration between the two surveys was 8.2 years, and the median follow-up after the second survey was 5.3 years. Habitual tea drinkers who maintained their habit in both surveys had a 39 per cent lower risk of incident heart disease and stroke, 56 per cent lower risk of fatal heart disease and stroke, and 29 per cent decreased risk of all-cause death compared to consistent never or non-habitual tea drinkers.
"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," said study senior author Dongfeng Gu.
Lower risks of heart disease and stroke
"Thus, frequent tea intake over an extended period may be necessary for the cardioprotective effect," Gu added. In a sub-analysis by type of tea, drinking green tea was linked with approximately 25 per cent 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 study said.
According to the researchers, two factors may be at play. First, green tea is a rich source of polyphenols which protect against cardiovascular disease and its risk factors, including high blood pressure and dyslipidaemia. Black tea is fully fermented and during this process polyphenols are oxidised into pigments and may lose their antioxidant effects. Second, black tea is often served with milk, which previous research has shown may counteract the favourable health effects of tea on vascular function, the study said.
