Greenberg James A, Boozer Carol N, Geliebter Allan
Department of Health and Nutrition Sciences, Brooklyn College, City University of New York, New York, NY 11210, USA.
Am J Clin Nutr. 2006 Oct;84(4):682-93. doi: 10.1093/ajcn/84.4.682.
Several prospective epidemiologic studies over the past 4 y concluded that ingestion of caffeinated and decaffeinated coffee can reduce the risk of diabetes. This finding is at odds with the results of trials in humans showing that glucose tolerance is reduced shortly after ingestion of caffeine or caffeinated coffee and suggesting that coffee consumption could increase the risk of diabetes. This review discusses epidemiologic and laboratory studies of the effects of coffee and its constituents, with a focus on diabetes risk. Weight loss may be an explanatory factor, because one prospective epidemiologic study found that consumption of coffee was followed by lower diabetes risk but only in participants who had lost weight. A second such study found that both caffeine and coffee intakes were modestly and inversely associated with weight gain. It is possible that caffeine and other constituents of coffee, such as chlorogenic acid and quinides, are involved in causing weight loss. Caffeine and caffeinated coffee have been shown to acutely increase blood pressure and thereby to pose a health threat to persons with cardiovascular disease risk. One short-term study found that ground decaffeinated coffee did not increase blood pressure. Decaffeinated coffee, therefore, may be the type of coffee that can safely help persons decrease diabetes risk. However, the ability of decaffeinated coffee to achieve these effects is based on a limited number of studies, and the underlying biological mechanisms have yet to be elucidated.
过去4年的几项前瞻性流行病学研究得出结论，摄入含咖啡因咖啡和脱咖啡因咖啡均可降低糖尿病风险。这一发现与人体试验结果相悖，人体试验表明，摄入咖啡因或含咖啡因咖啡后不久，葡萄糖耐量会降低，这表明饮用咖啡可能会增加患糖尿病的风险。本综述讨论了咖啡及其成分影响的流行病学和实验室研究，重点关注糖尿病风险。体重减轻可能是一个解释因素，因为一项前瞻性流行病学研究发现，饮用咖啡后糖尿病风险降低，但仅在体重减轻的参与者中出现这种情况。另一项此类研究发现，咖啡因和咖啡摄入量均与体重增加呈适度负相关。咖啡中的咖啡因和其他成分，如绿原酸和奎尼德，有可能参与导致体重减轻。已证明咖啡因和含咖啡因咖啡会使血压急性升高，从而对有心血管疾病风险的人构成健康威胁。一项短期研究发现，磨碎的脱咖啡因咖啡不会升高血压。因此，脱咖啡因咖啡可能是一种能够安全地帮助人们降低糖尿病风险的咖啡类型。然而，脱咖啡因咖啡实现这些效果的能力基于数量有限的研究，其潜在的生物学机制尚未阐明。
