Drinking 2–3 Cups of Coffee a Day Led to a Surprising Result [Health Issue]

[Financial News] A new study has found that drinking about two to three cups of caffeinated coffee every day can help delay cognitive decline and lower the risk of developing dementia. Similar benefits were observed in people who drank one to two cups of tea a day.
A research team led by Daniel Wang at Harvard Medical School reported these findings on the 10th in the Journal of the American Medical Association (JAMA), after analyzing more than 40 years of follow-up data from over 130,000 participants in the Nurses’ Health Study and the Health Professionals Follow-up Study.
The study is significant because it provides evidence that caffeine intake may help prevent dementia. Wang explained, "This study suggests that consuming caffeinated coffee or tea could be one piece of the puzzle when it comes to protecting cognitive function."
According to the analysis, the group in the top 25% for caffeine intake had a dementia incidence rate of 141 cases per 100,000 person-years. In comparison, the bottom 25% recorded 330 cases, indicating that the high-intake group had about an 18% lower risk of dementia.
People who regularly drank caffeinated coffee also showed a lower prevalence of self-reported cognitive decline. In addition, they performed relatively better on several objective cognitive function tests.
A similar pattern was observed in groups with higher tea consumption, but no such association appeared for decaffeinated coffee. Based on this, the researchers suggested that caffeine itself is likely the key factor behind the neuroprotective effect.
Cognitive benefits were most pronounced among participants who drank two to three cups of caffeinated coffee and one to two cups of tea per day. Notably, even at higher levels of caffeine intake, the study did not detect the adverse effects that some earlier research had raised concerns about.
Bioactive compounds in coffee and tea, such as polyphenols and caffeine, have long been regarded as neuroprotective agents that help prevent cognitive decline by suppressing inflammation and cellular damage. However, previous studies often had short follow-up periods or did not fully account for long-term consumption patterns and differences between beverages, leading to mixed findings on their relationship with dementia.
Using data from 131,821 participants in the long-running Nurses’ Health Study (NHS) and Health Professionals Follow-up Study (HPFS), the team conducted a detailed analysis of how caffeinated coffee, tea, and decaffeinated coffee affect cognitive health.
Participants were divided into four groups based on food-frequency questionnaires administered every two to four years. The researchers then tracked dementia diagnoses and results from subjective and objective cognitive assessments for up to 43 years.


hsg@fnnews.com Han Seung-gon Reporter