Effect of cocoa and green tea on biomarkers of glucose regulation, oxidative stress, inflammation and hemostasis in obese adults at risk for insulin resistance

• Published in: European journal of clinical nutrition Vol. 66; no. 10; pp. 1153 - 1159
• Main Authors: Stote, K S, Clevidence, B A, Novotny, J A, Henderson, T, Radecki, S V, Baer, D J
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.10.2012; Nature Publishing Group
• Subjects: 692/53; 692/699/1503/1702/393; Adult; Adults; Anti-Inflammatory Agents, Non-Steroidal - administration & dosage; Anti-Inflammatory Agents, Non-Steroidal - analysis; Anti-Inflammatory Agents, Non-Steroidal - therapeutic use; Antioxidants - administration & dosage; Antioxidants - analysis; Antioxidants - therapeutic use; Beverages; Beverages - analysis; Bioflavonoids; Biological and medical sciences; Biological markers; Biomarkers; Biomarkers - blood; Body Mass Index; C-reactive protein; Cacao - chemistry; Cardiovascular diseases; Clinical Nutrition; Cocoa; Complications and side effects; Composition; Cross-Over Studies; District of Columbia; Double-Blind Method; Epidemiology; Feeding. Feeding behavior; Female; Fibrinogen; Fibrinogen - analysis; Flavanols; Flavones; Flavonoids; Flavonols - administration & dosage; Flavonols - analysis; Flavonols - therapeutic use; Fundamental and applied biological sciences. Psychology; Glucose; Glucose metabolism; Green tea; Health aspects; Hemostasis; Hemostatics; Humans; Inflammation; Insulin; Insulin Resistance; Interleukin 6; Internal Medicine; Male; Medical sciences; Medicine; Medicine & Public Health; Metabolic Diseases; Middle Aged; Obesity; Obesity - blood; Obesity - diet therapy; Obesity - immunology; Obesity - metabolism; original-article; Overweight - blood; Overweight - diet therapy; Overweight - immunology; Overweight - metabolism; Oxidative Stress; Physiological aspects; Prevention; Public Health; Risk; Risk factors; Tea; Tea - chemistry; Type 2 diabetes; Vertebrates: anatomy and physiology, studies on body, several organs or systems; District of Columbia; United States; green tea; polyphenols; insulin resistance; cocoa; obesity; Endocrinopathy; Human; Obesity; Oxidative stress; Nutrition disorder; Biological marker; Metabolic diseases; Risk; Inflammation; Glucose; Target tissue resistance; Polyphenol; Regulation(control); Hemostasis; Risk factor; Phenols; Adult; Insulin resistance; Green tea; Nutritional status
• ISSN: 0954-3007; 1476-5640
• DOI: 10.1038/ejcn.2012.101

Background/Objectives: Flavanols may provide protection against insulin resistance, but little is known about the amounts and types of flavanols that may be efficacious. Subjects/Methods: This study was designed to determine whether cocoa flavanols, over a range of intakes, improve biomarkers of glucose regulation, inflammation and hemostasis in obese adults at risk for insulin resistance. As an adjunct, green tea and cocoa flavanols were compared for their ability to modulate these biomarkers. In a randomized crossover design, 20 adults consumed a controlled diet for 5 days along with four cocoa beverages containing 30–900 mg flavanol per day, or tea matched to a cocoa beverage for monomeric flavanol content. Results: Cocoa beverages produced no significant changes in glucose, insulin, total area under the concentration–time curve (AUC) for glucose or total insulin AUC. As the dose of cocoa flavanols increased, total 8-isoprostane concentrations were lowered (linear contrast, P =0.02), as were C-reactive protein (CRP) concentrations (linear contrast, P =0.01). The relationship between cocoa flavanol levels and interleukin-6 (IL-6) concentrations was quadratic, suggesting that a maximum effective dose was achieved (quadratic contrast, P =0.01). There were no significant effects on measured indices of glucose regulation, nor on those of total 8-isoprostane, CRP and IL-6 concentrations, when cocoa and green tea were compared. However, relative to cocoa, green tea lowered fibrinogen concentrations ( P =0.0003). Conclusions: Short-term intake of cocoa and green tea flavanols does not appear to improve glucose metabolism; they do affect selected markers of one or more measures of oxidative stress, inflammation or hemostasis in obese adults at risk for insulin resistance.