A new analysis published open access in the journal BMJ Mental Health presents intriguing findings on the association between daily coffee consumption and biological aging in individuals with severe mental disorders. At the center of the research is telomere length – protective “caps” at the ends of chromosomes – which is often used as a surrogate marker of cellular aging. People with schizophrenia, psychosis, and bipolar disorder, according to previous works, have shorter telomeres on average than the general population, pointing to accelerated biological aging. The authors of the new paper report that moderate coffee intake (approximately 3–4 cups per day) correlates with longer telomeres compared to people who do not drink coffee, while this pattern is not seen with very high intake (5+ cups daily). Although these are observational data, the message is important for daily practice: maintaining intake in the moderate range may go hand in hand with preserving cellular health in a population that often bears the burden of metabolic and oxidative stress.

Why telomeres are important for understanding mental health

Telomeres protect genetic material from damage during every cell division. They naturally shorten with age, but environmental factors such as chronic stress, smoking, inflammation, and oxidative pressure also affect them. It is precisely stressful life circumstances, metabolic comorbidities, higher rates of smoking, and some side effects of therapies that are more common in the population with severe mental disorders. Therefore, it is not a surprise that shorter telomeres are found on average in this group. The key question is whether lifestyle habits – diet, sleep, movement, and beverage intake – can modulate this biological trajectory. Coffee occupies a special place here because it combines caffeine (a stimulant with potential hemodynamic effects) and a wide range of polyphenols with antioxidant and anti-inflammatory properties.

Coffee, antioxidants, and biological aging

Coffee is one of the most globally consumed beverages and a source of numerous bioactive compounds: polyphenols, chlorogenic acids, and caffeine. While caffeine in larger doses can raise blood pressure or disrupt sleep, antioxidants from coffee can neutralize free radicals and reduce inflammatory events. Scientists have therefore long been interested in the potential link between coffee drinking habits and aging biomarkers. The new study focused precisely on this – whether there is a quantitative link between the number of cups of coffee and telomere length in subjects with diagnoses from the spectrum of severe mental disorders.

How the study was designed

The research team analyzed data collected as part of the Norwegian TOP cohort (Thematically Organised Psychosis). The sample included 436 adults, of which 259 had schizophrenia and 177 had affective disorders (bipolar disorder and severe depressive episodes with psychosis). Participants self-reported daily coffee intake and were classified into four groups based on this: do not drink coffee; drink 1–2 cups; drink 3–4 cups; drink 5 or more cups daily. Smoking patterns were also recorded (about three-quarters of the sample were smokers, with an average smoking duration of almost a decade). Telomere length was measured in leukocytes from blood samples using standardized laboratory procedures. Important: the design is observational, without intervention or random assignment, so we speak of association, not causation.

Key findings: A “J” shaped curve

The results showed a clear non-linear pattern. Compared to people who do not drink coffee, the group with 3–4 cups per day had statistically significantly longer telomeres. An assessment of biological age suggests that this profile is approximately equivalent to a “younger” biological status by about five years compared to non-consumers. Conversely, among people who drank 5 or more cups daily, a favorable effect was not observed; the authors warn that very high intake can stimulate the creation of reactive oxygen species and thereby neutralize the potential antioxidant benefits of coffee. It was also noted that people diagnosed with schizophrenia drank more coffee on average than participants with affective disorders, which further emphasizes the need for individualized interpretation of data.

How much is “moderate”: what public health practice says

Guidelines from various health bodies converge on a threshold of about 400 mg of caffeine daily as generally safe for most healthy adults, which roughly corresponds to 3–4 standard cups of filtered coffee. This limit also appears as a “sweet spot” in the study results: it is precisely in this range that longer telomere length is observed. However, one should keep in mind that caffeine content varies significantly between beverages (espresso, Turkish coffee, instant, “cold brew”), preparation methods, and serving sizes. Additionally, sensitivity to caffeine differs individually, and there are populations for whom stricter limits apply (e.g., pregnancy, some cardiac diagnoses, anxiety and sleep disorders). As a general rule, it is useful to monitor one's own sleep, pulse, and the appearance of unpleasant symptoms (tremors, palpitations) and adjust intake.

What this means for clinicians and public health communication

For doctors and mental health professionals, the practical message is cautiously optimistic. Moderate coffee drinking can be included in conversations about lifestyle habits with patients with schizophrenia, psychosis, or bipolar disorder, especially if there is an interest in strategies that support overall health and “healthier” aging. Here, interactions with therapy, smoking habits, sleep quality, and daily routine need to be assessed. Coffee is not a substitute for pharmacological treatment, psychotherapy, or behavioral changes, but it can be considered as part of a balanced regime, packaged with the promotion of physical activity, quality nutrition, and smoking cessation support.

Limitations and caution in interpretation

This is an observational study, so we cannot speak of a cause-and-effect relationship. It is possible that people who drink moderate amounts of coffee also have other habits that favor longer telomeres (better diet, more movement, more regular sleep rhythm). The authors also noted methodological limitations: detailed data on the type of coffee, preparation method, precise caffeine concentration, or consumption of other caffeinated beverages did not exist. The proportion of smokers was very high, which may act as a confounding factor given the faster metabolism of caffeine in smokers and the independent effects of smoking on oxidative stress. Finally, measuring telomeres in leukocytes reflects a systemic picture, but telomeres differ between tissues and are not the only indicator of biological age.

Link to earlier knowledge about coffee

Literature on coffee and health has become increasingly voluminous in recent years. Several review papers and population studies find favorable associations of moderate coffee intake with mortality and a range of chronic conditions, with an emphasis on individual differences and upper safety limits. For the cardiovascular system, the rule of measure applies: while moderate amounts are not associated with a permanent increase in blood pressure in most habitual consumers, excessive intake can cause palpitations, insomnia, and a short-term increase in pressure. In the context of mental health, the finding of longer telomeres with moderate intake builds on the idea that dietary and lifestyle patterns that reduce inflammation and oxidative stress can be a support to overall treatment.

What patients can practically do

• Keep intake in the range of up to four standard cups per day, unless a doctor recommends stricter limits.


• Prefer filtered coffee over unfiltered to reduce the intake of ingredients that adversely affect blood lipids.


• Avoid late caffeine intake (afternoon and evening) if there is a problem with insomnia or disrupted sleep rhythm.


• Pay attention to sugar and added calories in specialty drinks; “energy” drinks and supplements may contain very high doses of caffeine and sugar.


• Align habits with therapy and expert advice, especially in cardiovascular conditions, pregnancy, or breastfeeding.

Who these results mean the most to

The results are particularly relevant for people at risk of accelerated biological aging or in whom shorter telomere length has already been recorded previously. Populations with severe mental disorders often encounter an accumulation of risk factors: smoking, sedentary lifestyle, metabolic syndrome, adverse effects of antipsychotics on body weight and glucose metabolism. Adjusting lifestyle habits in a way that supports antioxidant balance – including moderate coffee drinking – could, at least partially, mitigate the biological consequences of these burdens. Of course, decisions should be made individually and in consultation with a doctor.

Short methodological note

Using telomere length from leukocytes as a measure of aging has advantages and disadvantages. The advantage is that it is a non-invasive biomarker that well reflects cumulative exposure to oxidative stress and inflammation. The disadvantage is variability between tissues and the fact that telomeres do not represent the only or necessarily the best indicator of biological age. In addition, the measurement method (qPCR vs. alternative techniques) and laboratory standardization can affect comparability between studies. Therefore, these findings should be interpreted as an important piece of the puzzle, but not as the final word on the relationship between coffee and biological age.

What follows in research

The authors call for longitudinal studies that would track changes in telomere length over time in relation to precisely quantified intake of coffee and other caffeinated beverages, while recording dietary patterns, sleep quality, and physical activity levels. Interventional trials – for example, randomized controlled trials with defined coffee intake and standardized biomarker measurement – could further clarify causality. It is also worth investigating differences between caffeinated and decaffeinated coffee and between different preparation methods (filtered, espresso, “cold brew”), as well as genetic variants of caffeine metabolism that may shape individual response.

Broader context: from the lab to the daily cup

Although the public often seeks simple rules, the science of nutrition and beverages rarely offers equations that apply to everyone. The genetics of caffeine metabolism, the gut microbiome, differences in coffee preparation methods, and cultural patterns make every recommendation approximate. Nevertheless, the consistency of findings that moderate drinking (3–4 cups) is associated with favorable outcomes – from cardiovascular profile to, now, telomere length in a vulnerable population – gives a reasonable basis for practical advice. The message is simple, but not banal: stick to moderation, observe one's own reactions, and incorporate coffee into a broader framework of a healthy routine. For some, this will also mean reducing intake or switching to a decaffeinated variant if side effects occur.

Note on date and interpretation of relative terms

This text was prepared on December 06, 2025, and relative terms such as “today” or “recently” are aligned with that date. Given the rapid influx of new publications, it is advisable to occasionally check for guideline updates and the latest systematic reviews, especially if making decisions related to personal health or clinical practice.

Additional information for editors and communicators

For portals covering public health and mental health topics, it is crucial to frame these findings without sensationalism. It is advisable to emphasize that these are observational data on a specific clinical cohort and that confirmations in other populations and designs are needed. At the same time, the limit of approximately 400 mg of caffeine daily should be transparently stated as a conservative guideline for most adults, with a note that individual tolerance and comorbidities may require stricter limits. It is especially important to communicate the potential risks of overindulgence: insomnia, anxiety, palpitations, elevated blood pressure, and interactions with medications.

What this is not

The findings do not suggest that people with severe mental disorders should “increase the dose” of coffee without restriction or that coffee is a therapy for psychiatric diagnoses. Discontinuing or changing prescribed therapy on one's own is not recommended. The message is balanced: maintaining intake in the moderate range, with a general focus on a healthy lifestyle and cooperation with a doctor, is reasonable and potentially beneficial.