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A Norwegian study published in BMJ Mental Health suggests that drinking three to four cups of coffee daily may be associated with slower cellular aging in people with major psychiatric disorders. The researchers measured telomere length — a marker of biological age — and found a J-shaped relationship between coffee intake and cellular markers.
What the study found and who was involved
The analysis used data from 436 adults enrolled in the Norwegian Thematically Organised Psychosis (TOP) study between 2007 and 2018. Participants included 259 people diagnosed with schizophrenia and 177 with affective disorders (such as bipolar disorder or major depressive disorder with psychosis). Researchers divided participants by self-reported daily coffee intake: none, 1–2 cups, 3–4 cups, and 5 or more cups.
After adjusting for age, sex, ethnicity, tobacco use, diagnostic category and treatment, the team observed that people who drank up to 3–4 cups per day had longer leukocyte telomeres than non-coffee drinkers. On average, telomere length in the 3–4 cup group corresponded to roughly five extra biological years compared with non-drinkers. That association disappeared for those consuming five or more cups daily, producing a J-shaped pattern.
Why telomeres matter for aging and mental health
Telomeres are repetitive DNA sequences that cap chromosome ends and protect genetic material from damage — much like the plastic tips on shoelaces. They naturally shorten with successive cell divisions and are sensitive to oxidative stress and inflammation. Accelerated telomere shortening has been reported in people with severe psychiatric illnesses, which may contribute to higher rates of age-related morbidity in these groups.
Because telomeres respond to environmental and lifestyle factors, scientists are investigating whether diet, exercise, smoking cessation and, in this case, coffee consumption can influence biological aging pathways.
Biological mechanisms: antioxidants, inflammation and limits
Coffee is a complex beverage containing polyphenols, chlorogenic acids and other compounds with antioxidant and anti-inflammatory properties. The authors propose that these molecules could help protect cells from oxidative damage and chronic inflammation — both of which accelerate telomere shortening.
However, the study authors also caution about potential harms from excessive consumption. High doses of caffeine or certain compounds formed during intense roasting could increase reactive oxygen species and counteract any benefits. Major public health agencies (including the NHS and the FDA) advise keeping daily caffeine intake under about 400 mg — roughly four standard cups of brewed coffee for most people.
Study design, confounders and important caveats
Crucially, this was an observational study, so it cannot prove cause and effect. Several potentially important details were not captured: the coffee bean type, brewing method, cup size, exact caffeine content, timing of consumption and intake of other caffeinated beverages. Smoking — common among participants (77%) — alters caffeine metabolism and was more prevalent and longer in duration among heavy coffee drinkers, which complicates interpretation.
Telomere length was measured in circulating white blood cells (leukocytes), a standard but indirect marker of cellular aging. While leukocyte telomere length is informative, it does not provide a complete picture of aging in other tissues.
Public health perspective and practical takeaways
The research offers a potential, low-cost behavioral link to slower cellular aging for a population often at increased biological risk. But clinicians and public-health professionals should temper enthusiasm: the association held only at moderate intake (3–4 cups) and was absent at higher consumption levels. For individuals with severe mental illness, broader lifestyle interventions — medication adherence, smoking cessation, balanced diet and physical activity — remain central to reducing long-term health risks.
Global coffee consumption is large (estimated at about 10.56 billion kilos in 2021–2022), so even modest effects on health markers could have broad implications. Still, personal tolerance, medication interactions and cardiovascular or sleep-related side effects must be considered before recommending higher coffee intake.
Future research directions
Researchers recommend longitudinal and interventional studies to test whether changing coffee consumption alters telomere dynamics and clinical outcomes. Trials should record coffee type, brewing methods, caffeine dose and timing, and ideally measure telomere length across multiple tissues. Understanding biochemical pathways — from polyphenol activity to effects on systemic inflammation — will be key to moving beyond correlation.
Expert Insight
"These findings are intriguing because they point to a modifiable lifestyle factor that could influence cellular aging in a vulnerable population," says Dr. Emma Lawson, a molecular psychiatrist at the University of Oslo. "But observational data can only take us so far — we need randomized trials that control for smoking, medication and diet before making clinical recommendations."
"In the meantime," Dr. Lawson adds, "moderation is sensible: for most adults, three to four cups of coffee per day appears safe and may carry benefits, but individual factors like sleep, anxiety and heart health should guide personal choices."
Overall, the study contributes to a growing literature on how everyday habits can shape biological aging, but it leaves open questions about causality, optimal dosing and mechanism. For now, moderate coffee remains a plausible, low-risk candidate in a wider strategy to support long-term health for people with major mental illness.
Source: scitechdaily
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