title: Effects of black tea on body composition and metabolic outcomes related to cardiovascular disease risk: a randomized controlled trial.
abstract: There is increasing evidence that tea and its non-caffeine components (primarily flavonoids) contribute to cardiovascular health. Randomized controlled trials have shown that tea can improve cardiovascular disease risk factors. We have previously reported a non-caffeine associated beneficial effect of regular black tea consumption on blood pressure and its variation.
  
  
  OBJECTIVE
  To explore the non-caffeine associated effects of black tea on body weight and body fat distribution, and cardiovascular disease related metabolic outcomes.
  
  
  METHODS
  regular tea-drinking men and women (n = 111; BMI 20-35 kg m(-2)) were recruited to a randomized controlled double-blind 6 month parallel-designed trial. Participants consumed 3 cups per day of either powdered black tea solids (tea) or a flavonoid-free flavour- and caffeine-matched placebo (control). Body weight, waist- and hip-circumference, endothelial function and plasma biomarkers were assessed at baseline, 3 months and 6 months.
  
  
  RESULTS
  Compared to control, regular ingestion of black tea over 3 months inhibited weight gain (-0.64 kg, p = 0.047) and reduced waist circumference (-1.88 cm, P = 0.035) and waist-to-hip ratio (-0.03, P = 0.005). These effects were no longer significant at 6 months. There were no significant effects observed on fasting glucose, insulin, plasma lipids or endothelial function.
  
  
  CONCLUSIONS
  Our study suggests that short-term regular ingestion of black tea over 3 months can improve body weight and body fat distribution, compared to a caffeine-matched control beverage. However, there was no evidence that these effects were sustained beyond 3 months.
authors.affiliation: Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Norway. s.k.bohn@medisin.uio.no.
authors.forename: Siv K
authors.initials: SK
authors.lastname: Bøhn
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Croft
authors.forename: Sally
authors.initials: S
authors.lastname: Burrows
authors.forename: Ian B
authors.initials: IB
authors.lastname: Puddey
authors.forename: Theo P J
authors.initials: TP
authors.lastname: Mulder
authors.forename: Dagmar
authors.initials: D
authors.lastname: Fuchs
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Woodman
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Hodgson
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood / Q000652:urine; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D001823:Body Composition / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D028241:Camellia sinensis / Q000737:chemistry*; D002318:Cardiovascular Diseases / Q000517:prevention & control*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D004311:Double-Blind Method; D004727:Endothelium / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005419:Flavonoids / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D010936:Plant Extracts / Q000008:administration & dosage; D013662:Tea / Q000737:chemistry*; D014280:Triglycerides / Q000097:blood; D055105:Waist Circumference / Q000187:drug effects
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D005419:Flavonoids; D010936:Plant Extracts; D013662:Tea; D014280:Triglycerides