Daily drinking habit linked to better brain health.

A long-term Harvard study of more than 131,000 health professionals found that higher regular consumption of coffee or tea was associated with lower rates of dementia and slower cognitive decline, with the lowest risk estimated around 2–3 cups of coffee or 1–2 cups of tea daily; the authors and outside experts note this is an association, not proof of protection.

Many people begin the day with a cup of coffee or tea, and a large new study has reported an association between that habit and brain health. Harvard researchers analysed dietary and cognitive data collected from over 131,000 health professionals and followed participants for an average of 43 years. They found that regular coffee and tea drinkers tended to perform better on cognitive tests and had lower observed rates of dementia. The researchers estimated the lowest associated risk around two to three cups of caffeinated coffee or one to two cups of tea daily. Authors and outside experts emphasised the study shows an association and not a cause-and-effect relationship. Key findings: - The analysis included more than 131,000 health professionals (about 86,000 women and 45,000 men) with an average follow-up of 43 years and 11,033 identified cases of dementia. - Participants with the highest coffee intake had an 18% lower risk of dementia compared with those who drank the least; regular tea drinkers showed a similar 16% reduced risk. - The researchers estimated the lowest associated dementia risk at roughly 2–3 cups of caffeinated coffee a day or 1–2 cups of tea a day, with no additional benefit observed at higher intake. - Regular coffee and tea consumers also showed a slower rate of cognitive decline on repeat testing compared with rare drinkers. - Study limitations noted by the authors and external experts include reliance in part on self-reported diagnoses and the relatively similar population of health professionals, so findings may not apply uniformly to other groups. Summary: The study reports modest associations between regular coffee or tea consumption and lower observed dementia risk, which the authors say could have meaningful implications at a population level if confirmed. Further research using different populations and methods to assess causality is needed; appropriate follow-up actions are undetermined at this time.