Caffeinated coffee consumption impairs blood glucose homeostasis in response to high and low glycemic index meals in healthy men

• Published in: The American journal of clinical nutrition Vol. 87; no. 5; pp. 1254 - 1261
• Main Authors: Moisey, Lesley L, Kacker, Sita, Bickerton, Andrea C, Robinson, Lindsay E, Graham, Terry E
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Nutrition 01.05.2008; American Society for Clinical Nutrition; American Society for Clinical Nutrition, Inc
• Subjects: Adolescent; Adult; Area Under Curve; Biological and medical sciences; blood glucose; Blood Glucose - drug effects; Blood Glucose - metabolism; C-Peptide - blood; Caffeine; Caffeine - pharmacology; Coffee; coffee (beverage); Coffee - chemistry; Cross-Over Studies; diet; Dietary Carbohydrates - pharmacokinetics; drinking; Edible Grain; Feeding. Feeding behavior; Fundamental and applied biological sciences. Psychology; Glucose; Glucose Tolerance Test; Glycemic Index; Health risk assessment; health status; homeostasis; Humans; Insulin; Insulin - blood; insulin secretion; Male; Men; Middle Aged; test meals; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Western diet; Human; Food intake; Low; Meal; Homeostasis; Glycemic index; Glucose; Coffee; Blood
• ISSN: 0002-9165; 1938-3207
• DOI: 10.1093/ajcn/87.5.1254

BACKGROUND: The ingestion of caffeine (5 mg/kg body weight) and a 75-g oral glucose load has been shown to elicit an acute insulin-insensitive environment in healthy and obese individuals and in those with type 2 diabetes. OBJECTIVE: In this study we investigated whether a similar impairment in blood glucose management exists when coffee and foods typical of a Western diet were used in a similar protocol. DESIGN: Ten healthy men underwent 4 trials in a randomized order. They ingested caffeinated (5 mg/kg) coffee (CC) or the same volume of decaffeinated coffee (DC) followed 1 h later by either a high or low glycemic index (GI) cereal (providing 75 g of carbohydrate) mixed meal tolerance test. RESULTS: CC with the high GI meal resulted in 147%, 29%, and 40% greater areas under the curve for glucose (P < 0.001), insulin (NS), and C-peptide (P < 0.001), respectively, compared with the values for DC. Similarly, with the low GI treatment, CC elicited 216%, 44%, and 36% greater areas under the curve for glucose (P < 0.001), insulin (P < 0.01), and C-peptide (P < 0.01), respectively. Insulin sensitivity was significantly reduced (40%) with the high GI treatment after CC was ingested compared with DC; with the low GI treatment, CC ingestion resulted in a 29% decrease in insulin sensitivity, although this difference was not significant. CONCLUSION: The ingestion of CC with either a high or low GI meal significantly impairs acute blood glucose management and insulin sensitivity compared with ingestion of DC. Future investigations are warranted to determine whether CC is a risk factor for insulin resistance.