Moderate coffee consumption may help slow biological ageing in people with severe mental illness, according to new research published in BMJ Mental Health. The study found that drinking up to four cups of coffee a day was linked to longer telomeres—protective DNA caps that indicate cellular ageing—equating to about five extra years of biological youth compared with non-coffee drinkers.
The research suggests that the benefits stop beyond four cups a day, which aligns with the maximum daily caffeine intake advised by health authorities such as the NHS and the U.S. Food and Drug Administration.
Telomeres, located at the ends of chromosomes, function like the plastic tips on shoelaces, preventing DNA strands from fraying. Although telomere shortening is a natural part of ageing, it often occurs more rapidly in people with major psychiatric conditions, including schizophrenia, bipolar disorder, and psychosis.
Researchers explored whether coffee, known for its antioxidant and anti-inflammatory properties, could influence this process. The study analyzed data from 436 adults enrolled in the Norwegian Thematically Organised Psychosis (TOP) project between 2007 and 2018. Among them, 259 participants had schizophrenia, while 177 had affective disorders such as bipolar disorder or major depressive disorder with psychosis.
Participants reported their daily coffee consumption, divided into four categories: none, 1–2 cups, 3–4 cups, and 5 or more cups. Smokers were also identified, as smoking accelerates caffeine metabolism. About 77% of participants were smokers, many of whom reported smoking for nearly a decade.
Tests of white blood cell samples revealed a J-shaped relationship between coffee intake and telomere length. Participants who drank 3–4 cups daily had significantly longer telomeres than both non-drinkers and heavy coffee consumers. Those drinking five or more cups a day, however, did not show protective effects.
After adjusting for age, sex, ethnicity, smoking, diagnosis, and medication, individuals consuming four cups a day had the telomere length of someone roughly five years younger in biological terms.
The study was observational, meaning it cannot confirm that coffee directly causes slower biological ageing. Researchers also lacked data on the type of coffee, brewing methods, or caffeine levels. Still, they pointed to plausible explanations, such as coffee’s antioxidant compounds reducing oxidative stress and inflammation—both known to accelerate cell ageing.
Given coffee’s vast global popularity—it’s estimated that 10.56 billion kilograms were consumed worldwide in 2021–22—the researchers cautioned that moderation is key. Exceeding four cups a day may lead to the opposite effect, potentially triggering cellular damage through excess reactive oxygen production. Global health agencies recommend limiting caffeine intake to no more than 400 milligrams daily.
Related topics
Mental Illness Linked to First Single Gene Found by Scientists
WVU Medicine Seeks Opioid Settlement Funds for Children’s Mental Health Inpatient Clinic
Bozeman Launches New Mental Health Treatment Center To Support Recovery
