title: Effect of cocoa and green tea on biomarkers of glucose regulation, oxidative stress, inflammation and hemostasis in obese adults at risk for insulin resistance.
abstract: OBJECTIVE
  Flavanols may provide protection against insulin resistance, but little is known about the amounts and types of flavanols that may be efficacious.
  
  
  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.
authors.affiliation: Food Components and Health Laboratory, Beltsville Human Nutrition Research Center, US Department of Agriculture, Agricultural Research Service, Beltsville, MD, USA. Kim.Stote@esc.edu
authors.forename: K S
authors.initials: KS
authors.lastname: Stote
authors.forename: B A
authors.initials: BA
authors.lastname: Clevidence
authors.forename: J A
authors.initials: JA
authors.lastname: Novotny
authors.forename: T
authors.initials: T
authors.lastname: Henderson
authors.forename: S V
authors.initials: SV
authors.lastname: Radecki
authors.forename: D J
authors.initials: DJ
authors.lastname: Baer
mesh_terms: D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000032:analysis / Q000627:therapeutic use; D000975:Antioxidants / Q000008:administration & dosage / Q000032:analysis / Q000627:therapeutic use; D001628:Beverages / Q000032:analysis; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002099:Cacao / Q000737:chemistry; D018592:Cross-Over Studies; D004219:District of Columbia; D004311:Double-Blind Method; D005260:Female; D005340:Fibrinogen / Q000032:analysis; D044948:Flavonols / Q000008:administration & dosage / Q000032:analysis / Q000627:therapeutic use; D006487:Hemostasis; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000178:diet therapy* / Q000276:immunology / Q000378:metabolism; D050177:Overweight / Q000097:blood / Q000178:diet therapy / Q000276:immunology / Q000378:metabolism; D018384:Oxidative Stress; D013662:Tea / Q000737:chemistry
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000975:Antioxidants; D015415:Biomarkers; D044948:Flavonols; D013662:Tea; D005340:Fibrinogen