Study: Coffee and Tea May Slow Brain Decline and Reduce the Risk of Dementia
A recent American study suggests that drinking coffee and tea may help preserve brain function and lower the risk of developing dementia, with clearer results observed among individuals who regularly consume moderate amounts.
Researchers from Harvard University, as reported by “Sky News,” found that people who consume higher amounts of caffeinated coffee have an 18% lower risk of developing dementia compared to those who consume smaller amounts. Similarly, higher tea consumption was associated with a 16% reduction in dementia risk.
The study followed approximately 131,000 participants over a period of 43 years and was published in the Journal of the American Medical Association. It also showed that cognitive decline occurred more slowly in individuals who regularly consumed greater amounts of coffee and tea compared to others.
In contrast, decaffeinated coffee showed no association with a reduced risk of dementia or improved mental performance, reinforcing the hypothesis that caffeine and certain biologically active compounds may play a key role.
The research team explained that components such as caffeine and polyphenols found in coffee and tea may help reduce inflammation and protect nerve cells from damage, which could explain the potential positive effects on cognitive health.
The study’s lead author, Daniel Wang from Harvard Medical School, stated that the strongest positive associations were observed at moderate consumption levels—specifically, two to three cups per day of caffeinated coffee and one to two cups per day of tea.
However, the researchers emphasized that the findings do not definitively prove that caffeine protects the brain. They noted that the observed effect remains relatively modest and that more effective strategies for maintaining mental function with age include regular physical exercise, a balanced diet, and adequate sleep.
Independent experts also expressed caution regarding the results. Susan Kohlhaas from Alzheimer’s Research UK said the study does not establish a direct causal relationship between coffee or tea consumption and brain protection. Tara Spires-Jones from the UK Dementia Research Institute pointed out methodological limitations, suggesting that lifestyle factors associated with drinking habits may explain the findings.
Meanwhile, Jules Griffin from the University of Aberdeen described the evidence as “convincing,” though he noted that the reduction in risk is relatively small. Simon White from the University of Cambridge added that the findings are not sufficient to recommend changes to individuals’ daily habits.
