People who drink a couple of teas or coffees a day appear to have a lower risk of dementia and slightly better cognitive performance, scientists say. A US study tracking more than 130,000 people for up to 43 years 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 than non-drinkers. The findings were published in the Journal of the American Medical Association.
Caffeinated coffee drinkers also showed marginally less cognitive decline and performed better on some brain function tests than those who chose decaf. No protective link appeared for decaffeinated coffee. The researchers stress the study cannot prove caffeine protects the brain, as other factors may explain the association. Lead author Yu Zhang of Harvard University said the results align with plausible biology, as caffeine and polyphenols may support vascular health and reduce inflammation.
Experts urge caution. Naveed Sattar of the University of Glasgow noted caffeine can have both helpful and harmful effects, including raising blood pressure in some people. Researchers emphasise that tea and coffee are not a cure, and that exercise, good sleep, and a healthy lifestyle remain the most reliable ways to protect brain health.
