Drinking three to four cups of coffee a day may slow cellular aging

By Priyanjana Pramanik, MSc.Reviewed by Lauren HardakerNov 28 2025

New research suggests that consuming three to four cups of coffee daily may help slow cellular aging in individuals with schizophrenia and affective disorders, uncovering a surprising lifestyle factor linked to biological resilience.

Study: Coffee intake is associated with telomere length in severe mental disorders. Image credit: PitukTV/Shutterstock.com

In a recent study published in BMJ Mental Health, researchers examined whether different levels of daily coffee consumption were associated with a marker of cellular aging in adults with severe mental disorders (SMD).

People who drank moderate amounts of coffee daily showed the longest telomeres. The most evident statistically significant difference was observed between non-drinkers and those consuming three to four cups per day. Some coffee drinkers show telomere lengths equivalent to being approximately five years biologically younger than non-drinkers.

Shortened telomeres contribute to aging in SMD

People with SMD experience substantially reduced life expectancy due to high rates of physical diseases commonly linked to aging, such as cardiovascular conditions and cancer. Researchers have therefore proposed accelerated biological aging in these groups, often assessed through telomere length, which naturally shortens with age.

Multiple studies show that individuals with schizophrenia or bipolar disorder typically have shorter telomere length than healthy peers, though the causes remain unclear. Because telomeres are sensitive to environmental influences, lifestyle factors such as diet have become important research targets.

Coffee is one of the world’s most widely consumed beverages. Moderate coffee consumption has been linked to cognitive benefits, reduced risks of neurodegenerative disorders, obesity, type 2 diabetes, certain cancers, and lower all-cause mortality. Evidence from population studies on coffee and telomere length is mixed, with some showing detrimental effects and others suggesting antioxidant-related protection.

Individuals with SMD tend to consume more caffeine than the general population, yet no study has specifically tested how coffee consumption relates to telomere length in schizophrenia or affective disorders.

Diagnostic and biological assessments

This cross-sectional study included 436 adults diagnosed with schizophrenia spectrum disorders or affective disorders, recruited across four psychiatric units in Norway. Participants with some neurological conditions, significant head trauma, or somatic illnesses affecting brain function were excluded.

Trained clinicians conducted diagnostic assessments. Medication use was extracted from medical records, reported as daily defined doses for major psychotropic classes. Coffee intake was measured through clinical interviews, where participants selected one of four categories: none, one or two cups per day, three or four cups per day, or five or more cups per day. Smoking status and smoking duration were also recorded.

Telomere length was measured from peripheral blood leukocytes, producing a telomere–to–single–copy gene ratio. Base-pair differences were translated into estimated years of accelerated aging.

Group differences in telomere length were evaluated using analysis of covariance (ANCOVA), adjusting for medication dosage, smoking duration, ethnicity, age, and sex. Additional sensitivity analyses tested interactions with sex and diagnosis and compared non-drinkers with those consuming between one and four cups each day.

Moderate coffee intake shows strongest telomere benefit

Across the 436 participants, coffee consumption groups differed mainly by age and smoking history. Those drinking five or more cups per day were older than non-drinkers and low-intake groups, and they also had the longest smoking histories.

Coffee use did not vary by sex or medication use, but individuals with schizophrenia consumed more coffee than those with affective disorders. Most participants were smokers, with an average of nine years of tobacco use.

Analyses showed a significant inverted J-shaped relationship between coffee intake and telomere length. After adjusting for age, sex, ethnicity, smoking duration, and medication, telomere length differed across consumption groups, with the clearest contrast between non-drinkers and those consuming three or four cups per day. This was the only comparison that had any statistical significance.

Moderate coffee intake was associated with longer telomeres, whereas very high intake of five or more cups daily did not show this benefit. When comparing non-drinkers with all participants consuming within the recommended range of one to four cups a day, coffee drinkers appeared biologically about five years younger, based on estimated telomere shortening rates.

These associations were consistent after adjusting for diagnosis, and there were no interactions by sex or diagnostic group, indicating similar effects in men and women and in schizophrenia versus affective disorders.

Lifestyle factors shape cellular aging

The study suggests that moderate coffee consumption is linked to longer telomeres, and therefore potentially slower cellular aging, in people with severe mental disorders. The pattern resembled an inverted J-curve: drinking up to four cups per day was associated with longer telomere length, but higher intake showed no advantage.

These findings align with some large population studies, though others report opposite or mixed results. Proposed mechanisms include antioxidants in coffee that may reduce inflammation and oxidative stress, as well as caffeine-related effects on telomerase pathways that influence telomere maintenance. These factors are especially relevant in schizophrenia and affective disorders, where accelerated aging is often observed.

Key limitations include reliance on self-reported coffee intake, lack of data on caffeine sources or coffee type, and absence of measures of inflammation or oxidative stress. The study was cross-sectional and lacked a healthy control group, which limited causal inference. Telomere length measurements provided an average rather than a distribution of short telomeres.

Overall, results suggest potential benefits of moderate coffee intake but possible harm at high levels, highlighting the importance of monitoring consumption in this population.

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