STUDY: Good news for coffee lovers concerned about dementia risks
In this DML Report…
A long-term study tracking more than 131,821 doctors and nurses for up to 43 years found that participants with the highest intake of caffeinated coffee had an 18 percent lower risk of dementia than those with little or no consumption.
Researchers analyzed data from the Nurses’ Health Study and the Health Professionals Follow-Up Study, using self-reported dietary questionnaires collected every four years and adjusting for factors including smoking, physical activity, and underlying health conditions. During the follow-up period, 11,033 participants developed dementia. The analysis showed that caffeinated coffee and tea consumption reduced the risk of cognitive decline, with participants who consumed the highest amounts also scoring higher on tests of overall cognitive function.
The benefits were most pronounced at two to three cups of caffeinated coffee per day or one to two cups of tea, identified as a “sweet spot” for risk reduction. Higher tea consumption produced similar results. Decaffeinated coffee did not show the same protective effects, suggesting caffeine is the key neuroprotective factor. Both coffee and tea contain bioactive compounds, such as polyphenols, that may reduce inflammation and cellular damage. Higher caffeine intake did not produce negative effects and provided consistent benefits even among those with a high genetic predisposition to dementia.
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Senior study author Daniel Wang, an assistant professor at Harvard Medical School, stated, “When searching for possible dementia prevention tools, we thought something as prevalent as coffee may be a promising dietary intervention.”
The observational study does not establish causation, and prior research on coffee and dementia has been inconsistent due to shorter follow-up periods. Dementia currently affects more than 6 million Americans and 55 million people worldwide, with over 100,000 U.S. deaths annually, according to the National Institutes of Health. Researchers described the effect size as small and positioned the findings as one of many lifestyle factors that may help protect cognitive health during aging.