Overview
- Researchers analyzed 436 adults with schizophrenia spectrum or affective disorders and found the longest leukocyte telomeres in those drinking three to four cups a day.
- The association followed an inverted J-shaped pattern, with no apparent telomere advantage at intakes of five cups or more.
- Compared with non-drinkers, participants consuming within one to four cups daily showed telomere lengths consistent with roughly five fewer biological years.
- Results were adjusted for age, sex, ethnicity, smoking duration, and medication, and people with schizophrenia reported higher coffee intake than those with affective disorders.
- Limitations include self-reported coffee use, no data on other caffeine sources or coffee type, a lack of healthy controls, and the observational design, prompting calls for longitudinal and mechanistic studies; common guidance caps caffeine at about 400 mg a day (roughly four cups).