近日一项研究发现，每天喝上两到三杯咖啡不仅会让你的一天过得更轻松，还有可能降低因心脏疾病或其它疾病发生死亡的风险。相关研究结果发表在国际学术期刊Circulation上，这项研究发现每天喝适量咖啡的人（每天不超过5杯）因心血管疾病、神经疾病、2型糖尿病以及自杀而导致死亡的风险会更低。
研究发现不管是含有咖啡因还是不含咖啡因的咖啡，都会带来类似的结果，这表明不仅是咖啡因能够为健康保驾护航，咖啡豆中的其他一些天然化合物也可能发挥作用。
文章第一作者Ming Ding这样说道："咖啡中具有生物活性的化合物能够降低胰岛素抵抗和系统性炎症，这可能也是喝咖啡降低死亡风险的重要原因。但是其中的生物学机制还需要更多研究来探讨。"
这项研究的数据来自三个大型研究，研究人员对参与者进行了30年跟踪调查研究，每四年时间以问卷形式评估参与者喝咖啡的情况。在研究期间共有19,524名女性以及12,432名男性因不同原因死亡。
一般来说，经常喝咖啡的人也更喜欢吸烟喝酒，为了排除吸烟造成的影响，研究人员在不吸烟者中重复了他们的分析，发现咖啡的保护性作用变得更加显著。研究人员表示，健康均衡的饮食应当包含咖啡的饮用，但对于一些特定人群，比如孕妇和儿童，从咖啡或其他饮品中摄入咖啡因应当更加小心。
这项研究表明适度饮用咖啡可能会带来一些健康获益，并非表明饮用咖啡与死亡风险降低之间存在确定因果关系。除此之外，咖啡究竟如何影响身体健康以及是否不同类型的咖啡都能够起到类似作用仍然需要更多研究来证实。
DOI: 10.1161/CIRCULATIONAHA.115.017341
Association of Coffee Consumption with Total and Cause-Specific Mortality in Three Large Prospective Cohorts.
Ming Ding1; Ambika Satija1; Shilpa N. Bhupathiraju1; Yang Hu1; Qi Sun2; Jiali Han3; Esther Lopez-Garcia4; Walter Willett2; Rob M. van Dam5; Frank B. Hu2*
Background-The association between consumption of caffeinated and decaffeinated coffee and risk of mortality remains inconclusive.
Methods and Results-We examined the associations of consumption of total, caffeinated, and decaffeinated coffee with risk of subsequent total and cause-specific mortality among 74,890 women in the Nurses' Health Study (NHS), 93,054 women in the NHS 2, and 40,557 men in the Health Professionals Follow-up Study. Coffee consumption was assessed at baseline using a semi-quantitative food frequency questionnaire. During 4,690,072 person-years of follow-up, 19,524 women and 12,432 men died. Consumption of total, caffeinated, and decaffeinated coffee were non-linearly associated with mortality. Compared to non-drinkers, coffee consumption one to five cups/d was associated with lower risk of mortality, while coffee consumption more than five cups/d was not associated with risk of mortality. However, when restricting to never smokers, compared to non-drinkers, the HRs of mortality were 0.94 (0.89 to 0.99) for ≤ 1 cup/d, 0.92 (0.87 to 0.97) for 1.1-3 cups/d, 0.85 (0.79 to 0.92) for 3.1-5 cups/d, and 0.88 (0.78 to 0.99) for > 5 cups/d (p for non-linearity = 0.32; p for trend < 0.001). Significant inverse associations were observed for caffeinated (p for trend < 0.001) and decaffeinated coffee (p for trend = 0.022). Significant inverse associations were observed between coffee consumption and deaths due to cardiovascular disease, neurological diseases, and suicide. No significant association between coffee consumption and total cancer mortality was found.
Conclusions-Higher consumption of total coffee, caffeinated coffee, and decaffeinated coffee was associated with lower risk of total mortality.