Tea is popular among older adults, and various researchers have recently been investigating the potential beneficial effects of the beverage.
A separate study from the NUS that appeared in Aging last June, for example, found that tea may have properties that help brain areas maintain healthy cognitive function.
“Our study offers the first evidence of the positive contribution of tea drinking to brain structure and suggests a protective effect on age-related decline in brain organization.”
Junhua Li, lead author
That earlier paper also cites research showing that tea and its ingredients — catechin, L-theanine, and caffeine — can produce positive effects on mood, cognitive ability, cardiovascular health, cancer prevention, and mortality.
However, defining the exact role of tea in preventing depression is difficult, especially due to the social context in which people often consume it. Particularly in countries such as China, social interaction may itself account for some or even all of the drink’s benefits.
Feng Qiushi and Shen Ke led the new study, which tracks this covariate and others, including gender, education, and residence, as well as marital and pension status.
The team also factored in lifestyle habits and health details, including smoking, drinking alcohol, daily activities, level of cognitive function, and degree of social engagement.
In addition, the authors write, “The study has major methodological strength,” citing a few of its attributes.
Firstly, they note, it could more accurately track an individual’s tea-drinking history because “instead of examining tea-drinking habit [only] at the time of survey or in the preceding month/year, we combined the information on frequency and consistency of tea consumption at age 60 and at the time of assessment.”
Once the researchers had classified each person as one of four types of tea drinker according to how often they drank the beverage, they concluded:
“[O]nly consistent daily drinkers, those who had drunk tea almost every day since age 60, could significantly benefit in mental health.”