People who drink a small amount of tea or coffee each day may face a lower risk of dementia, researchers say. A large US study found that those who drank two to three cups of caffeinated coffee or one to two cups of caffeinated tea daily had a 15–20% lower dementia risk over four decades than non-drinkers. The findings appeared in the Journal of the American Medical Association.
The analysis followed more than 130,000 people enrolled in long-running US health studies. Regular coffee drinkers also showed slightly less cognitive decline and better performance on some brain tests than people who chose decaf. Researchers found no protective link for decaffeinated coffee.
Lead author Yu Zhang of Harvard University said the study could not prove cause and effect. He noted that caffeine users might differ in other ways that reduce dementia risk. Coffee and tea contain caffeine and polyphenols that may support brain health by improving blood flow and reducing inflammation.
Experts cautioned against seeing caffeine as a cure. University of Glasgow professor Naveed Sattar said caffeine can have mixed effects, including raising blood pressure in some people. Researchers stress that exercise, diet, sleep, and managing health risks remain the most reliable ways to protect brain health.
