JAMA：喝咖啡或茶有益大脑健康？哈佛大学研究发现，每天2~3杯咖啡或1~2杯茶更佳

Core Findings - The study published in JAMA indicates that long-term consumption of caffeinated coffee and tea is associated with a lower risk of dementia, with optimal protective effects observed at moderate intake levels of about 2-3 cups of caffeinated coffee or 1-2 cups of tea daily [1][4] Study Design and Data - The research utilized data from the Nurses' Health Study (NHS) and the Health Professionals Follow-up Study (HPFS), involving 131,821 participants who were free of cancer, Parkinson's disease, or dementia at baseline, with a follow-up period of 43 years [2][5] - Participants' caffeine intake was assessed through food frequency questionnaires every 2-4 years, and dementia events were confirmed via death records and physician diagnoses [2][6] Results and Analysis - A total of 11,033 dementia events were recorded, and after adjusting for various confounding factors, higher intake of caffeinated coffee was linked to an 18% lower risk of dementia compared to those with the lowest intake [3][6] - The risk of subjective cognitive decline was also lower among high coffee consumers (9.5% vs. 7.8%) [3][6] - For tea drinkers, those with moderate and high intake levels had a 9% and 14% lower risk of dementia, respectively [3][6] Cognitive Performance - Higher caffeinated coffee consumption was associated with better objective cognitive performance, with participants in the highest intake group scoring higher on cognitive assessments compared to those with the lowest intake [7] - Similar trends were observed for tea consumption, while decaffeinated coffee did not show any association with reduced dementia risk or cognitive improvement [4][7] Conclusion - The large-scale study supports the notion that moderate consumption of caffeinated coffee and tea may be beneficial for brain health, suggesting that incorporating these beverages into a balanced diet and healthy lifestyle could help in dementia prevention [4][7]