科学家们在咖啡中识别出两种化合物，咖啡醇和咖啡酸，可能降低罹患2型糖尿病的风险。
2型糖尿病患者会抵抗胰岛素。为了克服这种抵抗，胰腺会产生更多的胰岛素，但最终，依然会相对不足。高血糖会导致健康问题，比如失明和神经损伤。一些遗传和生活方式危险因素与2型糖尿病相关联，但喝咖啡已经被表明有助于防止其发病。之前认为咖啡因是这种益处的原因，但研究表明咖啡因对葡萄糖和胰岛素仅有短期影响，而且不含咖啡因的咖啡也拥有同样的预防效果。为了研究咖啡的多种生物活性成分中，到底是那些在预防糖尿病方面发挥作用，S?ren Gregersen和他的同事在大鼠细胞系中检测了不同咖啡物质的影响。
研究人员在实验室里研究了不同咖啡成分对细胞的影响。在添加葡萄糖时，咖啡醇（Cafestol）和咖啡酸（caffeic）都增加了胰岛素的分泌。该团队还发现，咖啡醇会增加肌肉细胞对葡萄糖的摄取，与目前抗糖尿病处方药的水平相匹配。研究人员表示，咖啡醇的双重益处使其成为预防和治疗2型糖尿病的优秀候选者。不过，由于咖啡过滤器会去除大量咖啡醇，因此其他化合物也可能有助于这些健康益处。
DOI:10.1021/acs.jnatprod.5b00481
标题：Cafestol, a Bioactive Substance in Coffee, Stimulates Insulin Secretion and Increases Glucose Uptake in Muscle Cells: Studies in Vitro
摘要：Diet and exercise intervention can delay or prevent development of type-2-diabetes (T2D), and high habitual coffee consumption is associated with reduced risk of developing T2D. This study aimed to test whether seleced bioactive substances in coffee acutely and/or chronically increase insulin secretion from β-cells and improve insulin sensitivity in skeletal muscle cells. Insulin secretion from INS-1E rat insulinoma cells was measured after acute (1-h) and long-term (72-h) incubation with bioactive substances from coffee. Additionally, we measured uptake of radioactive glucose in human skeletal muscle cells (SkMC) after incubation with cafestol. Cafestol at 10–8?and 10–6?M acutely increased insulin secretion by 12% (p?< 0.05) and 16% (p?< 0.001), respectively. Long-term exposure to 10–10?and 10–8?M cafestol increased insulin secretion by 34% (p?< 0.001) and 68% (p?< 0.001), respectively. Caffeic acid also increased insulin secretion acutely and chronically. Chlorogenic acid, trigonelline, oxokahweol, and secoisolariciresinol did not significantly alter insulin secretion acutely. Glucose uptake in SkMC was significantly enhanced by 8% (p?< 0.001) in the presence of 10–8?M cafestol. This newly demonstrated dual action of cafestol suggests that cafestol may contribute to the preventive effects on T2D in coffee drinkers and be of therapeutic interest.