Overview
- Analysis of 436 adults in Norway’s TOP cohort found a J-shaped link between daily coffee intake and leukocyte telomere length.
- Participants drinking 3–4 cups had telomere lengths consistent with roughly five fewer biological years than non-drinkers after adjustments.
- No benefit was seen at five or more cups per day, aligning with guidance to limit caffeine to about 400 mg daily.
- Most participants smoked (about 77%), and heavier coffee drinkers had smoked longer, highlighting a key potential confounder.
- The BMJ Mental Health paper lacked details on coffee type, timing, and exact caffeine levels, so it cannot establish causation.