Research conducted by scientists at Harvard University has identified a specific daily intake of coffee and tea that may help reduce the risk of dementia. The comprehensive study suggests that moderate consumption of these caffeinated beverages is associated with improved cognitive health.
The findings indicate that individuals who consume approximately two to three cups of caffeinated coffee per day experience an 18 percent lower risk of developing dementia, while those who drink one to two cups of tea daily show a 16 percent reduced risk. The research involved an analysis of data from 131,000 health workers, tracked over an average period of 43 years.
Study Details and Findings
Lead author Yu Zhang from the TH Chan School of Public Health at Harvard emphasized the importance of identifying lifestyle factors that can influence dementia risk. “Dementia is one of the most important and challenging public health problems worldwide,” Zhang stated. “So identifying modifiable lifestyle factors that may be linked to dementia risk is critical.”
The study included participants from various backgrounds, notably 86,000 female NHS nurses and 45,000 male health professionals in the United States. Participants completed questionnaires regarding their dietary habits every two to four years, focusing on their consumption of caffeinated coffee, decaffeinated coffee, and tea. Cognitive performance was also assessed through standardized tests.
Throughout the follow-up period, researchers identified 11,033 cases of dementia, with results showing that higher caffeinated coffee intake correlated with enhanced cognitive performance among the NHS nurses. Interestingly, decaffeinated coffee did not show any association with a reduced risk of dementia or improved cognitive capabilities.
Limitations and Expert Commentary
Despite the promising findings, experts have cautioned against drawing definitive conclusions. Dr. Susan Kohlhaas, executive director of research at Alzheimer’s Research UK, noted that the study demonstrates an association rather than a causal relationship. “People who drink coffee or tea may also differ in other ways that affect brain health,” she explained.
Professor Tara Spires-Jones, a prominent figure at the UK Dementia Research Institute and a professor at the University of Edinburgh, added that observational research cannot conclusively prove that caffeine intake is the sole reason for lower dementia risk. Factors such as sleep disruption and cardiovascular health may also play significant roles.
The researchers acknowledged that self-reported data could lead to inaccuracies, particularly since participants in early stages of dementia might struggle with accurately recalling their caffeine intake.
Overall, while the study presents compelling evidence linking coffee and tea consumption to lower dementia risk, further research is necessary to clarify the underlying mechanisms and confirm these associations across diverse populations.
