New research published in BMJ Mental Health indicates that drinking three to four cups of coffee per day may be linked to slower cellular aging among people with schizophrenia and affective disorders. The study explored the association between coffee consumption and telomere length, a marker of biological aging, in adults diagnosed with severe mental disorders.
Researchers conducted a cross-sectional analysis involving 436 adults diagnosed with either schizophrenia spectrum or affective disorders. Participants were recruited from four psychiatric units in Norway. Those with certain neurological conditions, significant head trauma, or illnesses affecting brain function were excluded from the study.
Participants' coffee intake was assessed through clinical interviews, categorizing their consumption as none, one or two cups per day, three or four cups per day, or five or more cups per day. Other variables recorded included smoking status and duration, medication use, age, sex, and ethnicity.
The study found that individuals who consumed three to four cups of coffee daily had the longest telomeres compared to non-drinkers. "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," according to the research findings.
Telomere length was measured using blood samples and adjusted for various factors such as medication dosage and smoking history. Analysis revealed an inverted J-shaped relationship between coffee intake and telomere length: moderate consumption (three to four cups) was associated with longer telomeres while higher intake did not confer additional benefits.
"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," stated the researchers.
The associations held true after adjusting for diagnosis type and other demographic factors. There were no significant differences by sex or diagnostic group regarding the impact of coffee on telomere length.
While previous studies have shown mixed results about coffee's effect on biological aging markers like telomeres in general populations, this is among the first studies focusing specifically on individuals with severe mental disorders—a group known for increased rates of physical diseases related to aging.
The authors noted several limitations: reliance on self-reported data for coffee consumption; lack of information about caffeine sources or specific types of coffee; absence of direct measures for inflammation or oxidative stress; cross-sectional design without healthy controls; and use of average rather than distributional measures for telomere length.
Despite these limitations, the study suggests potential health implications for moderate coffee consumption among people living with schizophrenia or affective disorders but cautions against excessive intake.
