Drinking coffee or tea daily could help protect the brain’s healthy ageing, new research shows.
Moderate caffeine consumption, two to three cups of caffeinated coffee or one to two cups of tea daily, may lower the risk of dementia, slow cognitive decline, and preserve cognitive function.
“When searching for possible dementia prevention tools, we thought something as prevalent as coffee may be a promising dietary intervention,” said senior author Daniel Wang, associate scientist at Mass General Brigham Department of Medicine and assistant professor at Harvard Medical School.
The results, published in JAMA, found that moderate caffeine consumption was associated with up to an 18 percent lower risk of dementia.
The benefits were most pronounced among participants who consumed caffeine in moderate amounts.
However, higher caffeine intake did not lead to negative effects and appeared to offer similar neuroprotective benefits to moderate consumption.
Coffee and tea contain bioactive ingredients such as polyphenols and caffeine, which could act as neuroprotective factors by reducing inflammation and cellular damage while supporting cognitive health.
How was the study done?
The study looked at more than 130,000 participants who underwent dietary, dementia, and cognitive assessments. They were followed for up to 43 years, allowing researchers to examine how caffeinated coffee, tea, and decaffeinated coffee affected dementia risk and cognitive health over time.
During the follow-up period, 11,033 participants developed dementia.
In both men and women, the highest caffeine intake had an 18 percent lower risk of dementia compared with those who drank little or none.
Coffee drinkers also reported lower symptoms of subjective cognitive decline, the self-perceived experience of memory loss or confusion, at 7.8 percent versus 9.5 percent.
Previous studies have linked caffeine to improved insulin sensitivity and vascular function, which may contribute to its protective effects against cognitive decline.
The authors caution that, as an observational study, the results cannot establish direct causality. It also did not account for differences in tea or coffee types, or in how they were consumed, such as roast level, product origin, or brewing technique.
The challenge of tackling dementia
Early prevention remains key in dementia, as current treatments offer limited benefits once symptoms appear, the study said.
Focusing on prevention has led researchers to investigate the role that lifestyle factors, such as diet, play in dementia development.
Dementia typically develops along a continuum, from subjective cognitive decline to mild cognitive impairment, and eventually to clinical dementia
The researchers noted that, while the results are encouraging, it is important to remember that the effect size is small and that there are multiple ways to protect cognitive function as we age.
“Our study suggests that caffeinated coffee or tea consumption can be one piece of that puzzle,” Wang said.
