Moderate Coffee Consumption Linked to Slower Biological Aging in Severe Mental Illness: New Study

London, UK — A daily habit of drinking three to four cups of coffee may offer unexpected protective benefits against biological aging for individuals living with severe mental disorders, according to new research published in BMJ Mental Health.

The study, led by researchers at King’s College London and the University of Oslo, suggests that moderate coffee consumption is associated with longer telomeres—essential DNA structures that serve as markers of cellular age. For patients with conditions such as schizophrenia and bipolar disorder, who statistically face a significantly shorter life expectancy than the general population, these findings provide a promising, albeit complex, insight into the role of lifestyle factors in health management.

The “Sweet Spot” for Cellular Health

The cross-sectional study, drawing on data from 436 participants in the Norwegian Thematically Organized Psychosis (TOP) study, identified a specific “sweet spot” for consumption. Researchers found an inverted J-shaped relationship between coffee intake and telomere length: benefits peaked at three to four cups per day but diminished significantly when consumption exceeded this amount.

Participants who consumed this moderate amount had telomeres that were, on average, longer than those of non-coffee drinkers. In biological terms, this difference translated to being approximately five years younger.

“On one hand, we know that excessive coffee consumption can have negative effects on health, such as reducing sleep quality. However, our new study suggests that coffee consumption up to a certain point may have benefits for biological aging,” said Dr. Monica Aas, the study’s senior author and a researcher at King’s College London, in a press statement.

Understanding Telomeres and Mental Health

To understand the significance of these findings, it helps to understand telomeres. Often compared to the plastic aglets at the tips of shoelaces, telomeres are protective caps at the ends of chromosomes that prevent DNA from fraying or tangling.

Every time a cell divides, these telomeres get slightly shorter. Eventually, they become too short to protect the DNA, causing the cell to stop functioning or die—a fundamental process of aging.

Individuals with severe mental illness (SMI), including schizophrenia and major depressive disorder with psychosis, often experience “accelerated biological aging.” Research has consistently shown that this population has shorter telomeres and a life expectancy that is, on average, 15 years shorter than the general public. Factors contributing to this gap include higher rates of cardiovascular disease, side effects of medication, higher smoking rates, and chronic stress.

This new study is the first to investigate whether coffee—a rich source of antioxidants and anti-inflammatory compounds—might influence this specific biomarker in psychiatric populations.

Mechanism: More Than Just Caffeine

While the study did not isolate specific biological mechanisms, the researchers hypothesize that the benefit stems from coffee’s bioactive compounds, such as polyphenols, rather than caffeine alone. These compounds are known to reduce oxidative stress and inflammation, two key drivers of telomere shortening.¹²

However, the “Goldilocks” effect obse³rved in the data is crucial. W⁴hile three to four cups appeared protective, drinking five or more cups per day showed no benefit and, in some models, was associated with shorter telomeres.

“Studies such as this support the idea that we should move away from viewing coffee as simply ‘good or bad,’ and instead consider a more balanced view,” Dr. Aas noted.

Expert Perspectives and Limitations

Independent experts caution that while the results are intriguing, they should be interpreted with care. Dr. Elizabeth Akam, a Senior Teaching Fellow in Biosciences at Loughborough University, emphasized the complexity of coffee as a variable.

“A noteworthy limitation of this study is that it treats coffee as if it were a single substance,” Akam said in a reaction via the Science Media Center. “However, coffee contains many different compounds, and we don’t know which of these were administered, in what doses, or how much actually ended up in the bloodstream.”

The study also relied on self-reported coffee intake, which can be imprecise. Furthermore, it did not distinguish between brewing methods (e.g., filtered vs. instant) or account for the exact caffeine content, which can vary wildly between brands and preparations. Most critically, because the study was observational, it cannot prove that drinking coffee directly causes longer telomeres—only that there is a statistical link.

Implications for Public Health

For healthcare professionals and patients, the findings offer a nuanced takeaway. Coffee, a beverage often scrutinized for its potential to increase anxiety or disrupt sleep, may have a place in a healthy lifestyle for those with severe mental illness, provided it is consumed in moderation.

The results align with general health guidelines, such as those from the European Food Safety Authority and the U.S. FDA, which generally consider up to 400mg of caffeine (roughly four cups of brewed coffee) to be safe for most adults.

“As people with severe mental disorders tend to have high coffee consumption, our study suggests potential health benefits by monitoring coffee consumption to reduce intake above the recommended daily dose,” the authors wrote.

For the millions living with severe mental health diagnoses, this research underscores the power of modifiable lifestyle factors. While coffee is not a cure, it may be a small, enjoyable tool in the broader strategy of protecting physical health alongside mental well-being.

Medical Disclaimer:

This article is for informational purposes only and should not be considered medical advice. Always consult with qualified healthcare professionals before making any health-related decisions or changes to your treatment plan. The information presented here is based on current research and expert opinions, which may evolve as new evidence emerges.

References

Study Citation:

• Mlakar, V., Di Forti, M., Halff, E.F., et al. (2025). “Coffee intake is associated with telomere length in severe mental disorders.” BMJ Mental Health, 28(1). DOI: 10.1136/bmjment-2025-301700. Published online November 25, 2025.