Your morning cup of coffee or tea may be doing far more than waking you up. New research suggests that moderate caffeine consumption could help keep the brain sharp for decades.
A major study published in the Journal of the American Medical Association (JAMA) and funded by the National Institutes of Health has found that drinking two to three cups of caffeinated coffee or one to two cups of tea daily is associated with a significantly lower risk of dementia.
Notably, the protective link held even among people genetically predisposed to Alzheimer’s and other forms of cognitive decline.
The benefit, however, disappeared when participants consumed decaffeinated coffee.
While regular and decaf coffee share similar antioxidants and nutrients, regular coffee contains roughly 80–100 mg of caffeine per cup compared to just 2–7 mg in decaf — a difference that appears to matter for brain health.
The findings arrive at a critical time.
Dementia, a progressive syndrome affecting memory, thinking and behaviour, has become a global public health challenge amid rapidly ageing populations. In 2021, an estimated 5.7 crore people worldwide were living with the condition, according to the World Health Organisation (WHO).
FOUR DECADES OF DATA OFFER CLARITY
Researchers tracked participants for up to 43 years through two long-running cohorts: the Nurses’ Health Study and the Health Professionals Follow-up Study. Participants, typically in their mid-40s or early 50s at the start, regularly reported their dietary and lifestyle habits.
Over the study period, 11,033 participants developed dementia, confirmed through physician diagnoses or death records.
Compared with people who consumed almost no caffeine, those who drank between one and five cups of caffeinated coffee daily had about a 20 percent lower risk of dementia.
Participants who drank at least one cup of caffeinated tea each day saw roughly a 15 percent reduction in risk.
WHY CAFFEINE MAY PROTECT THE BRAIN
Experts say coffee and tea are rich in bioactive compounds such as polyphenols and caffeine, both of which have been linked to reduced inflammation and protection against cellular damage — two processes implicated in cognitive decline.
While earlier studies on coffee and dementia produced mixed results, many were limited by shorter follow-up periods or insufficient tracking of long-term consumption patterns.
The depth and duration of data from these two major cohorts helped address those gaps.
Participants who consumed caffeinated coffee also performed better on certain objective cognitive tests. Tea drinkers showed similar trends.
Decaffeinated coffee did not demonstrate the same protective association, strengthening the case that caffeine itself may play a central role — though researchers caution that more studies are needed to confirm the precise mechanisms.
Interestingly, the strongest cognitive benefits were seen among those consuming two to three cups of caffeinated coffee or one to two cups of tea daily.
Higher intake did not appear to produce harm and offered comparable protective effects, countering concerns raised in some earlier research.
The findings add to a growing body of evidence linking moderate coffee consumption — about two to five cups a day — to broader health benefits, including longer lifespan, improved liver health, lower risk of type 2 diabetes, reduced cardiovascular disease risk, and protection against Parkinson’s and even certain cancers.
For millions who rely on their daily brew, the message is encouraging: that familiar cup may be doing more than boosting alertness — it could be helping safeguard your brain for the long run.
