People who drink a few cups of tea or coffee daily show a lower risk of dementia, scientists say.
A US study tracked more than 130,000 adults over up to four decades.
Those who drank two to three coffees or one to two teas daily had a 15–20% lower dementia risk.
Researchers published the findings in Journal of the American Medical Association.
Caffeinated coffee drinkers also showed slightly less cognitive decline over time.
Decaffeinated coffee showed no protective link.
Lead author Yu Zhang from Harvard University said the study cannot prove cause and effect.
Caffeine users may differ in other ways that protect brain health.
Coffee and tea contain caffeine and polyphenols that may reduce inflammation and oxidative stress.
Caffeine also links to lower diabetes risk, a known dementia factor.
Experts say healthy lifestyle choices still matter most.
Regular exercise, good sleep, and balanced diets remain key to brain health.
