Coffee and Tea Consumption Linked to Lower Dementia Risk, Study Finds

Moderate daily consumption of caffeinated coffee or tea may significantly reduce the risk of dementia and slow cognitive decline, according to a new study published in JAMA. The research, conducted by investigators from Mass General Brigham, Harvard T.H. Chan School of Public Health, and the Broad Institute of MIT and Harvard, analyzed data from over 130,000 participants.

Long-Term Study Reveals Protective Effects

The prospective cohort study analyzed data from the Nurses’ Health Study (NHS) and the Health Professionals Follow-Up Study (HPFS), tracking participants for up to 43 years. Researchers examined the relationship between consumption of caffeinated coffee, tea, and decaffeinated coffee and long-term brain health outcomes, including dementia diagnoses, subjective cognitive concerns, and objective cognitive performance. Mass General Brigham

Key Findings

• Individuals who consumed higher amounts of caffeinated coffee had an 18% lower risk of developing dementia compared to those who rarely or never drank it.
• Higher caffeinated coffee intake was also associated with lower rates of subjective cognitive decline (7.8% versus 9.5%) and improved performance on certain cognitive tests.
• Similar benefits were observed among tea drinkers, with 1-2 cups per day showing positive effects.
• Decaffeinated coffee did not demonstrate the same protective associations.
• The most significant benefits were seen with 2-3 cups of caffeinated coffee or 1-2 cups of tea per day.
• The study found the benefits were consistent regardless of genetic predisposition to dementia.

Why Coffee and Tea May Protect the Brain

Coffee and tea contain compounds like polyphenols and caffeine, which are believed to support brain health. These substances may assist reduce inflammation and limit cellular damage, both of which are linked to cognitive decline. Harvard Gazette

Study Details and Funding

The study involved 131,821 participants from the Nurses’ Health Study and Health Professionals Follow-Up Study. Over the course of the study, 11,033 participants developed dementia. The research was supported by grants from the National Institutes of Health. ScienceDaily

Expert Perspective

“When searching for possible dementia prevention tools, we thought something as prevalent as coffee may be a promising dietary intervention—and our unique access to high quality data through studies that has been going on for more than 40 years allowed us to follow through on that idea,” said senior author Daniel Wang, MD, ScD, associate scientist with the Channing Division of Network Medicine in the Mass General Brigham Department of Medicine and assistant professor at Harvard Medical School. Mass General Brigham

Important Considerations

While the results are encouraging, researchers emphasize that the effect size is small and that coffee or tea consumption is just one piece of the puzzle when it comes to protecting cognitive function. Early prevention is crucial, as current dementia treatments offer limited benefits once symptoms appear.

Contact Information

For media inquiries, contact Mark Murphy at Mass General Brigham Media Relations (mmurphy90@mgb.org) or Maya Brownstein at Harvard T.H. Chan School of Public Health Media Relations (mbrownstein@hsph.harvard.edu). Nurses’ Health Study