Your morning espresso may do more than wake you up. It may help speed up the aging of your brain. A large US study published in the Journal of the American Medical Association on February 9 found that people who regularly drank moderate amounts of caffeinated coffee or tea were less likely to develop dementia.The analysis is based on two longitudinal health cohorts, the Nurses’ Health Study and the Health Professionals Follow-up Study, which followed 1,31,821 adults for up to 43 years. Over 11,000 participants developed dementia during follow-up. After adjusting for lifestyle and health factors, people with high intakes of caffeinated coffee had an 18% lower risk than those who drank less or never drank caffeinated coffee, with the best benefit seen at two to three cups a day. One to two cups of black tea daily showed a similar association, but decaffeinated coffee had no effect.Higher intake of caffeinated coffee was also associated with fewer complaints of memory loss and slightly better performance on objective cognitive tests, especially in women. This benefit is based on a clear period of moderation and there is no additional benefit from consuming large amounts.Commenting on the findings, Manjari Tripathi, head of neurology at the All India Institute of Medical Sciences, said that moderate consumption of caffeinated coffee, especially before 2pm, is associated with a lower risk of neurodegenerative diseases such as dementia and Parkinson’s disease. But she cautioned that these conditions are complex and shaped by multiple factors, including genetics, lifestyle, diet, education, obesity, diabetes, blood pressure and long-term cholesterol management.She also warned that excess caffeine can disrupt sleep and cause heart rhythm problems, especially in older people. Consuming coffee late in the day or in large quantities can cause insomnia, which itself can affect memory. She said moderation remains important.Dr. Praveen Gupta, a neurologist at Fortis Hospital in Gurgaon, placed the study’s findings in the Indian and Asian context and said there were no large-scale Indian dementia cohort studies that looked at coffee and tea intake on the scale of a US study. He noted that tea, not coffee, is the predominant drink in India, and that evidence from small studies in China and Japan suggests that green tea may be associated with reduced cognitive decline, although results for coffee remain mixed.Dr. Gupta added that resistance varies widely. Although one to three cups of caffeinated coffee or tea a day is well tolerated by many older adults, caffeine can worsen symptoms in people with insomnia, anxiety, acid reflux, heart rhythm disorders, and high blood pressure. He said any recommendations should be tailored to the individual’s health status, rather than being applied across the board.