Could Your Daily Cuppa Help Protect Against Dementia?
A major study tracking over 131,000 healthcare workers for more than four decades has found that regular, moderate consumption of caffeinated tea and coffee may be associated with a reduced risk of developing dementia.
The research, published in JAMA on 9 February, examined data from 86,000 female NHS nurses in the UK and 45,000 male health professionals in the United States. Participants were followed for an average of 43 years and answered questions about their tea and coffee drinking habits every two to four years.
During the study period, researchers identified 11,033 cases of dementia among participants.
According to the analysis conducted by scientists at Harvard University, those who consumed moderate amounts of caffeinated beverages showed the lowest dementia risk.
The optimal intake appeared to be around two to three cups of coffee or one to two cups of tea daily.
Dr Susan Kohlhaas, Executive Director of Research at Alzheimer’s Research UK, explained:
“This level of caffeine intake also linked to slightly better scores on memory and thinking tests, although the differences were small.”
Despite the encouraging findings, experts emphasise that the results should not be interpreted as definitive proof that tea and coffee protect the brain.
“This research doesn’t prove that coffee or tea protect the brain,” Dr Kohlhaas cautioned. “This study shows an association, not a cause-and-effect relationship. People who drink coffee or tea may also differ in other ways that affect brain health, even after careful adjustment.”
The study’s limitations include its reliance on self-reported diagnoses and its focus on relatively similar groups of health professionals, which may limit how applicable the findings are to the wider population.
Because the research was observational rather than interventional, further studies will be needed before any firm conclusions can be drawn about whether caffeinated drinks can actively reduce dementia risk.
Lead author Yu Zhang stressed the importance of continuing this line of research: “Dementia is one of the most important and challenging public health problems worldwide, and there are still very limited effective treatments. So, identifying modifiable lifestyle factors that may be linked to dementia risk is critical.”
Experts agree that whilst no single food or drink can prevent dementia, further research into how dietary factors affect dementia risk—and what changes occur in the brain as a result—will be essential for developing future prevention strategies.
