Drinking a maximum of 3–4 cups of coffee a day may slow the "biological" aging of people with severe mental illness, by lengthening their telomeres—indicators of cellular aging—and giving them the equivalent of 5 extra biological years, compared with non-coffee drinkers, finds research published in BMJ Mental Health.
But no such effects were observed beyond this quota, which is the maximum daily intake recommended by several international health authorities, including the NHS and the US Food and Drug Administration.
Telomeres sit at the end of chromosomes and perform a role similar to the plastic tips on the end of shoelaces. While telomere shortening is a natural part of the aging process, it seems to be accelerated in those with major psychiatric disorders, such as psychosis, schizophrenia, and bipolar disorder, note the researchers.
Study details and participant information
Telomeres are sensitive to environmental factors, including, possibly, diet. And coffee, when drunk in moderation, has been associated with various health benefits, prompting the researchers to explore whether it might influence the rate at which telomeres shorten in people with major mental ill health.
They included 436 adult participants from the Norwegian Thematically Organized Psychosis (TOP) study, recruited between 2007 and 2018: 259 had schizophrenia; the rest (177) had affective disorders, including bipolar disorder and major depressive disorder with psychosis.
Participants were asked how much coffee they drank every day and were grouped into four categories: zero (44); 1–2 cups; 3–4 cups (110); and 5 or more cups. And they were asked whether they smoked, and if so, for how long they had done so.
Participants who drank 5+ cups a day were significantly older than those who drank none or 1–2 cups a day. And those with schizophrenia drank significantly more coffee than those with an affective disorder.
Coffee intake is associated with telomere length in severe mental disorders, BMJ Mental Health (2025). DOI: 10.1136/bmjment-2025-301700
