Drinking a couple of teas or coffees a day may lower the risk of dementia, scientists say. A large US study found people who drank two to three cups of caffeated coffee or one to two cups of caffeinated tea daily had a 15–20% lower dementia risk. They also showed slightly better cognitive performance over time.
Researchers analysed health data from more than 130,000 participants followed for up to 43 years. The findings appeared in the Journal of the American Medical Association. Caffeinated coffee drinkers showed less cognitive decline than those who chose decaf. No link emerged between decaffeinated coffee and dementia.
Lead author Yu Zhang from Harvard University said the study could not prove cause and effect. He noted that lifestyle factors might explain part of the link. Coffee and tea contain caffeine and antioxidants that may support brain and vascular health.
Experts cautioned against viewing caffeine as a cure. University of Glasgow professor Naveed Sattar said caffeine has both positive and negative effects on the brain. Researchers stressed that exercise, diet, sleep, and blood pressure control remain key to protecting cognitive health.
