Acute effects of decaffeinated coffee and the major coffee components chlorogenic acid and trigonelline on incretin hormones,” Nutrition and Metabolism

OBJECTIVE — Coffee consumption has been associated with lower risk of type 2 diabetes. We evaluated the acute effects of decaffeinated coffee and the major coffee components chloro-genic acid and trigonelline on glucose tolerance. RESEARCH DESIGNANDMETHODS — We conducted a randomized crossover trial of the effects of 12 g decaffeinated coffee, 1 g chlorogenic acid, 500 mg trigonelline, and placebo (1 g mannitol) on glucose and insulin concentrations during a 2-h oral glucose tolerance test (OGTT) in 15 overweight men. RESULTS — Chlorogenic acid and trigonelline ingestion significantly reduced glucose (0.7 mmol/l, P 0.007, and 0.5 mmol/l, P 0.024, respectively) and insulin (73 pmol/l, P 0.038, and117 pmol/l, P 0.007) concentrations 15 min following an OGTT compared with placebo. None of the treatments affected insulin or glucose area under the curve values during the OGTT compared with placebo. CONCLUSIONS — Chlorogenic acid and trigonelline reduced early glucose and insulin responses during an OGTT. Diabetes Care 32:1023–1025, 2009 In prospective cohort studies, highercoffee consumption has been associ-ated with a lower risk of type 2 diabetes (1,2). Associations have been similar for caffeinated and decaffeinated coffee (1,3–5), suggesting that coffee compo-nents other than caffeine have beneficial effects on glucose homeostasis. Coffee is a major source of the phenolic com-pound chlorogenic acid (6) and the vi-tamin B3 precursor trigonelline (7), which have been shown to reduce blood glucose concentrations in animal stud-ies (5 – 8). This is the first study to in-vestigate the acute effects of chlorogenic acid and trigonelline on glucose toler-ance in humans