According to the latest issue of the BMJ Mental Health journal, a new study by an international team led by King's College London suggests that drinking no more than three to four cups of coffee a day may help slow down the cellular aging process in patients with severe mental illness.
Cell telomeres naturally shorten with age, and this shortening process is often more pronounced in patients with severe mental illnesses such as schizophrenia and bipolar disorder.
To understand whether coffee intake affects telomere length, the research team analyzed data from 436 adult participants in the Norwegian Subject-Oriented Psychiatric Study. The results showed that participants who drank 3 to 4 cups of coffee daily had significantly longer telomeres than those who did not drink coffee, but no similar trend was observed in those who drank more than 5 cups daily. This difference persisted after adjusting for factors such as smoking, age, sex, and medication.
It's worth noting that the "3 to 4 cups" figure used in the study follows the common epidemiological conversion, which is approximately 80-100 mg of caffeine per cup. Modern commercial coffee shops typically serve larger drinks with higher caffeine content. Therefore, for those who drink instant coffee or homemade small cups of brewed coffee, "3 to 4 cups per day" is more suitable. However, if drinking large commercial Americanos, 1 to 2 cups may be close to the optimal intake recommended in the study.
The research team emphasized that this study was an observational study and could not prove that coffee itself causes telomere elongation. Furthermore, it did not record potential confounding factors such as coffee type, drinking time, and other caffeinated beverages.