A study has found that people with major psychiatric conditions may age more slowly at the cellular level if they drink 3-4 cups of coffee a day.
This moderate habit was tied to longer telomeres, a marker of biological aging. Drinking more than four cups did not show the same effect. Researchers suggest coffee’s antioxidant and anti-inflammatory compounds may play a role.
Moderate Coffee Intake and Slower Biological Aging
Research published in the open-access journal BMJ Mental Health reports that drinking up to 3-4 cups of coffee a day may help slow the biological aging of people with severe mental illness. This amount of coffee was linked to longer telomeres—indicators of cellular aging—and the researchers estimate that this difference is roughly equal to 5 extra biological years when compared with people who do not drink coffee.
These potential benefits were not seen at higher levels of consumption. The 3-4 cup limit also matches the daily maximum recommended by major health bodies, including the NHS and the US Food and Drug Administration.
What Telomeres Are and Why They Matter
Telomeres sit at the ends of chromosomes and function much like the plastic tips that prevent shoelaces from unraveling. Telomere shortening naturally occurs with age, but the process appears to happen more quickly in people with major psychiatric disorders. The researchers note that this includes conditions such as psychosis, schizophrenia, and bipolar disorder.
Because telomeres respond to environmental factors, including diet, the team investigated whether coffee might play a role in slowing telomere loss in people living with serious mental illness. Coffee has been linked to certain health benefits when consumed in moderation, making it a relevant focus for study.
Who Took Part in the Study
The analysis drew on 436 adults enrolled in the Norwegian Thematically Organised Psychosis (TOP) study between 2007 and 2018. Of these participants, 259 had schizophrenia, while the remaining 177 had affective disorders, including bipolar disorder and major depressive disorder with psychosis.
Participants reported the amount of coffee they drank each day and were divided into four groups: none (44 people), 1-2 cups, 3-4 cups (110 people), and 5 or more cups. They were also asked about their smoking habits and duration of smoking.
Coffee Consumption, Smoking, and Participant Differences
Those who consumed 5 or more cups of coffee per day were noticeably older than individuals who drank none or only 1–2 cups. Participants with schizophrenia also tended to drink more coffee than those with affective disorders.
Smoking influences how quickly the body processes caffeine. Approximately three-quarters of participants (77%; 337 people) were smokers, and on average, they had smoked for 9 years. Individuals who consumed 5 or more cups of coffee daily had smoked for significantly longer than the other groups.
How Telomere Length Was Measured
Researchers measured telomere length using white blood cells (leucocytes) taken from blood samples. When comparing the four coffee groups, the results formed a J-shaped pattern.
Participants who drank up to 3-4 cups a day had longer telomeres than those who drank no coffee. This association was not observed in people who consumed five or more cups daily.
Those who averaged four cups a day showed telomere lengths consistent with a biological age about 5 years younger than those of non-coffee drinkers. This estimate accounted for age, sex, ethnicity, tobacco use, type of mental illness, and treatment.
Study Limitations and Possible Biological Explanations
Because this was an observational study, the researchers stress that it cannot confirm a direct cause-and-effect link. They also note that several potentially influential factors were not recorded, such as the type of coffee consumed, when it was consumed, the actual caffeine content, and whether participants drank other caffeinated beverages.
Even so, they point to plausible biological reasons for the findings. Coffee contains strong antioxidant and anti-inflammatory compounds that may help protect cells.
“Telomeres are highly sensitive to both oxidative stress and inflammation, further highlighting how coffee intake could help preserve cellular aging in a population whose pathophysiology may be predisposing them to an accelerated rate of aging,” they explain.
Global Coffee Popularity and Safety Considerations
Coffee remains widely consumed around the world. The researchers note that an estimated 10.56 billion kilos were consumed globally in 2021-2022.
Despite its potential advantages, they caution that “consuming more than the daily recommended amount of coffee may also cause cellular damage and [telomere] shortening through the formation of reactive oxygen species.” They emphasize that international health authorities recommend limiting caffeine intake to no more than 400 mg/day (4 cups of coffee).
Reference: “Coffee intake is associated with telomere length in severe mental disorders” by Vid Mlakar, Marta Di Forti, Els F Halff, Deepak P Srivastava, Ibrahim Akkouh, Srdjan Djurovic, Carmen Martin-Ruiz, Daniel S Quintana, Viktoria Birkenæs, Nils Eiel Steen, Monica BEG Ormerod, Ole A Andreassen and Monica Aas, 25 November 2025, BMJ Mental Health.
DOI: 10.1136/bmjment-2025-301700
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.