Drinking tea socially is uplifting, but researchers report tea drinking by older adults is clinically beneficial as well.
A peer-reviewed analysis of more than 13,000 elders living in China reveals a strong association between consistent and frequent tea drinking and fewer symptoms of depression. The results, published in the journal BMC Geriatrics, were based on the Chinese Longitudinal Healthy Longevity Survey (CLHLS), which was conducted between 2005 and 2014.
Researchers divided respondentsinto four groups based on the frequency, and the type of tea they drank, those60 and older demonstrated "a significant benefit in mental health."
Those who drank the most tea sharedseveral characteristics, including:
- Theywere more likely to be educated, married, and pensioners.
- Teadrinkers also exhibited higher cognitive and physical function.
- Theywere older, male, and urban residents.
- Theywere more socially involved and more likely to drink alcohol and smoke.
Depressionis one of the most common mental disorders for the elderly, often causing greatsuffering in later life, according to the study’s authors. About 7% ofindividuals older than 60 worldwide suffer from ‘major depressive disorder.’
Asthe number of older people increases globally, several studies of risk factorsranging from biomarkers, behavioral characteristics, socioeconomic status,marital status, urban vs. rural home life, and community involvement pointed totea drinking. A 2012 study found one-third of elderly Chinese aged 75 and oversuffered severe depressive symptoms.
Healthprofessionals who study mental health are aware of tea’s popularity with the elderly,but they have long debated whether benefits result from biochemical componentsof tea or the social context of tea drinking.
Researchersin this study focused on biochemical mechanisms. One hypothesis, advanced in anearlier study published in the journal Aging, is that tea catechins,especially epigallocatechin gallate (EGCG), could exert antidepressant-likeeffects and prevent a reduction in brain dopamine concentration. Another theoryis that theanine, one of the major amino acid contained in green tea leaves,could block the binding of L-glutamic acid and lead to lower post-stresscortisol and greater subjective relaxation, according to the article published byDr. Junhua Li.
A team led by researcher FengQiushi, an associate professor at NUS Sociology (NationalUniversity Singapore) and Associative Professor Shen Ke from Fudan University inShanghai, examined gender, education, residence, marital and pension status andalso factored in lifestyle habits and health details such as smoking, drinkingalcohol, daily activities, level of cognitive function and degree of socialengagement.
AssocProf Feng and his team controlled for covariates that could have significantassociations with elderly depression.
The team found “consistent andfrequent tea consumption, according to our study, was associated withsignificantly fewer depressive symptoms for old Chinese individuals, evenadjusting for their socioeconomic status, lifestyle, health status, and socialengagement.”
“In addition, the protective roleof tea consumption was particularly strong for the males and younger elderly,”wrote Feng.
Thecorrelation between tea drinking and depression is yet to be proven causative,but Feng said, “The promotion of the traditional lifestyle of tea drinkingcould be a cost-effective way towards healthy aging for China.”
Thestudy expands the work of Assistant Professor Feng Lei at NUS Psychological Medicine, who systematicallyinvestigated thepositive effect of tea-drinking on brain function, mental health, and mortalityin old age.
Assoc Prof. Feng and his team are now collecting new data from the CLHLS about tea-drinking. "This new round of data collection has distinguished different types of tea such as green tea, black tea, and oolong tea so that we could see which type of tea really works for alleviating depressive symptoms," according to the Science Blog.