Drinking tea at least three times a week is linked with a longer and healthier life, according to a study published today in the European Journal of Preventive Cardiology.
“Habitual tea consumption is associated with lower risks of cardiovascular disease and all-cause death,” said lead author Dr. Xinyan Wang of the Chinese Academy of Medical Sciences, Beijing, China. “The favourable health effects are most robust for green tea and for long-term habitual tea drinkers,” she added.
The analysis included 100,902 participants of the China-PAR project. 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 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.
In a subanalysis 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 death. However, no significant associations were observed for black tea.
Dr. Gu noted that a preference for green tea is unique to East Asia: “In our study population, 49% of habitual tea drinkers consumed green tea most frequently, while only 8% preferred black tea. 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.”
The researchers suggest 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 authors concluded that randomised trials are warranted to confirm the findings and provide evidence for dietary guidelines and lifestyle recommendations.
May 3, 2022