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, according to research published in BMJ Mental Health.
However, this beneficial effect was not observed in individuals who consumed more than this amount, which aligns with the maximum daily intake recommended by several international health authorities, including the NHS and the US FDA.
Telomeres are protective caps at the end of chromosomes that naturally shorten with age. This process appears to be accelerated in people with psychiatric conditions such as psychosis, schizophrenia, and bipolar disorder.
Researchers explored whether coffee, known for its antioxidant and anti-inflammatory properties, might influence telomere shortening in this population.
The study analyzed data from 436 adult participants in the Norwegian Thematically Organized Psychosis (TOP) study between 2007 and 2018. Among them, 259 had schizophrenia, while 177 had affective disorders including bipolar disorder and major depression with psychosis.
Participants were divided into four groups based on coffee consumption: none (44), 1–2 cups, 3–4 cups (110), and 5+ cups. Smoking habits were also recorded.
The study finds drinking up to 3–4 cups of coffee daily was associated with longer telomeres, indicating slower biological aging.
Participants drinking 4 cups per day had telomere lengths consistent with a biological age 5 years younger than non-drinkers. No telomere benefit was seen in those drinking 5+ cups daily. The group consuming 5+ cups also tended to be older and had longer smoking histories.
Telomere length was assessed using white blood cells (leukocytes) from blood samples. Results followed a J-shaped curve with the most benefit seen at 3–4 cups per day.
This was an observational study, so causation cannot be confirmed. The study also lacked data on coffee type, caffeine content, and other sources of caffeine.
Nonetheless, researchers suggest coffee’s antioxidant and anti-inflammatory properties may protect against telomere shortening. Overconsumption, however, may produce reactive oxygen species that harm cells.
International guidelines continue to recommend a caffeine limit of 400 mg per day, or around four cups of coffee.
If you care about health, please read studies that scientists find a core feature of depression and this metal in the brain strongly linked to depression.
For more health information, please see recent studies about drug for mental health that may harm the brain, and results showing this therapy more effective than ketamine in treating severe depression.
The study is published in BMJ Mental Health.
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