People who drink two to three cups of tea or coffee a day have a lower risk of dementia and slightly better cognitive performance than those who do not, a new study shows. The study found that long-term consumption of two to three cups of caffeinated coffee or one to two cups of caffeinated tea daily was linked to a 15–20% lower risk of dementia. Published in the Journal of the American Medical Association, the research analyzed health records from more than 130,000 healthy adults aged 40 and older. It also found that caffeinated coffee drinkers reported slightly less cognitive decline than those who opted for decaffeinated coffee and performed better on some objective brain function tests. Although the findings suggest tea and coffee may benefit brain health, the study cannot prove causation, as caffeine drinkers may be less prone to dementia for other reasons. “Our study alone can’t prove causality, but to our knowledge, it is the best evidence to date looking at coffee and tea intake and cognitive health, and it is consistent with plausible biology,” the study’s lead author, Yu Zhang, said. The positive effects may be linked to the polyphenols and caffeine found in tea and coffee, which can improve vascular health and reduce inflammation. These compounds are also known to reduce oxidative stress, a process in which harmful atoms and molecules called free radicals damage cells and tissues.
