title: Impact of phenolic-rich olive leaf extract on blood pressure, plasma lipids and inflammatory markers: a randomised controlled trial.
abstract: OBJECTIVE
  Dietary polyphenols have been demonstrated to favourably modify a number of cardiovascular risk markers such as blood pressure (BP), endothelial function and plasma lipids. We conducted a randomised, double-blind, controlled, crossover trial to investigate the effects of a phenolic-rich olive leaf extract (OLE) on BP and a number of associated vascular and metabolic measures.
  
  
  METHODS
  A total of 60 pre-hypertensive [systolic blood pressure (SBP): 121-140 mmHg; diastolic blood pressure (DBP): 81-90 mmHg] males [mean age 45 (±SD 12.7 years, BMI 26.7 (±3.21) kg/m2] consumed either OLE (136 mg oleuropein; 6 mg hydroxytyrosol) or a polyphenol-free control daily for 6 weeks before switching to the alternate arm after a 4-week washout.
  
  
  RESULTS
  Daytime [-3.95 (±SD 11.48) mmHg, p = 0.027] and 24-h SBP [-3.33 (±SD 10.81) mmHg, p = 0.045] and daytime and 24-h DBP [-3.00 (±SD 8.54) mmHg, p = 0.025; -2.42 (±SD 7.61) mmHg, p = 0.039] were all significantly lower following OLE intake, relative to the control. Reductions in plasma total cholesterol [-0.32 (±SD 0.70) mmol/L, p = 0.002], LDL cholesterol [-0.19 (±SD 0.56) mmol/L, p = 0.017] and triglycerides [-0.18 (±SD 0.48), p = 0.008] were also induced by OLE compared to control, whilst a reduction in interleukin-8 [-0.63 (±SD 1.13) pg/ml; p = 0.026] was also detected. Other markers of inflammation, vascular function and glucose metabolism were not affected.
  
  
  CONCLUSIONS
  Our data support previous research, suggesting that OLE intake engenders hypotensive and lipid-lowering effects in vivo.
authors.affiliation: Hugh Sinclair Unit of Human Nutrition, Department of Food and Nutritional Sciences, University of Reading, Reading, Berkshire, RG6 6AP, UK.
authors.forename: Stacey
authors.initials: S
authors.lastname: Lockyer
authors.affiliation: Hugh Sinclair Unit of Human Nutrition, Department of Food and Nutritional Sciences, University of Reading, Reading, Berkshire, RG6 6AP, UK.
authors.forename: Ian
authors.initials: I
authors.lastname: Rowland
authors.affiliation: Hugh Sinclair Unit of Human Nutrition, Department of Food and Nutritional Sciences, University of Reading, Reading, Berkshire, RG6 6AP, UK. j.p.e.spencer@reading.ac.uk.
authors.forename: Jeremy Paul Edward
authors.initials: JPE
authors.lastname: Spencer
authors.affiliation: Hugh Sinclair Unit of Human Nutrition, Department of Food and Nutritional Sciences, University of Reading, Reading, Berkshire, RG6 6AP, UK.
authors.forename: Parveen
authors.initials: P
authors.lastname: Yaqoob
authors.affiliation: School of Food and Nutrition, College of Health, Massey University, Auckland, New Zealand.|Food and Nutrition Flagship, Commonwealth Scientific Industrial Research Organisation (CSIRO), Adelaide, Australia.
authors.forename: Welma
authors.initials: W
authors.lastname: Stonehouse
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D002784:Cholesterol / Q000097:blood*; D018592:Cross-Over Studies; D016207:Cytokines / Q000097:blood; D004311:Double-Blind Method; D006801:Humans; D007249:Inflammation / Q000097:blood; D057888:Iridoid Glucosides; D039823:Iridoids / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D031658:Olea / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D059808:Polyphenols / Q000494:pharmacology*; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D016207:Cytokines; D057888:Iridoid Glucosides; D039823:Iridoids; D010936:Plant Extracts; D059808:Polyphenols; D014280:Triglycerides; C002769:oleuropein; D002097:C-Reactive Protein; D002784:Cholesterol
keywords: Blood pressure; Cardiovascular disease; Oleuropein; Olive leaf; Plasma lipids; Polyphenols