title: Effect of low doses of long-chain n-3 PUFAs on endothelial function and arterial stiffness: a randomized controlled trial.
abstract: BACKGROUND
  The dietary intake of n-3 (omega-3) long-chain PUFAs (LC-PUFAs) from fish may improve endothelial function and arterial stiffness.
  
  
  OBJECTIVE
  The objective was to test the hypothesis that increasing intakes of n-3 LC-PUFAs-equivalent to the consumption of 1, 2, or 4 portions of oily fish per week-favorably affects endothelial function and arterial stiffness.
  
  
  METHODS
  A parallel-design, randomized, double-blind study compared daily doses of 0.45, 0.9, and 1.8 g n-3 LC-PUFAs (EPA:DHA ratio of 1.51:1) with placebo (refined olive oil). The primary and secondary outcomes were changes in flow-mediated dilatation (FMD) of the brachial artery, arterial stiffness, and blood pressure. Nonsmoking men (n = 142) and women (n = 225) aged 45-70 y were randomly assigned to treatment for 12 mo; 312 subjects completed the intervention.
  
  
  RESULTS
  Compliance with the intervention was corroborated by significant dose-dependent increases in the proportions of EPA and DHA in erythrocyte lipids and a 16.5% reduction in serum triacylglycerol concentrations with 1.8 g n-3 LC-PUFAs/d. FMD was lower in men than in women (P < 0.0001) and decreased with age (ρ = 0.270, P < 0.001) but was not significantly (P = 0.781) related to n-3 LC-PUFA intake. The mean changes in FMD (95% CIs) compared with placebo were 0.1% (-0.9%, 1.1%), -0.3% (-1.3%, 0.6%), and -0.3% (-1.3%, 0.7%) with daily intakes of 0.45, 0.9, and 1.8 g n-3 LC-PUFAs, respectively. No significant treatment effects were noted for arterial stiffness and central mean or 24-h ambulatory blood pressure.
  
  
  CONCLUSIONS
  Intakes of n-3 LC-PUFAs ≤1.8 g/d do not improve endothelial function in healthy adults. The trial is registered at controlled-trials.com as ISRCTN66664610.
authors.affiliation: Diabetes and Nutritional Sciences Division, School of Medicine, King's College London, London, United Kingdom. tom.sanders@kcl.ac.uk
authors.forename: Thomas A B
authors.initials: TA
authors.lastname: Sanders
authors.forename: Wendy L
authors.initials: WL
authors.lastname: Hall
authors.forename: Zoitsa
authors.initials: Z
authors.lastname: Maniou
authors.forename: Fiona
authors.initials: F
authors.lastname: Lewis
authors.forename: Paul T
authors.initials: PT
authors.lastname: Seed
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Chowienczyk
mesh_terms: D000368:Aged; D001916:Brachial Artery / Q000502:physiology*; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000517:prevention & control*; D002320:Cardiovascular Physiological Phenomena; D019587:Dietary Supplements; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use; D004311:Double-Blind Method; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use; D004548:Elasticity; D004730:Endothelium, Vascular / Q000502:physiology*; D004912:Erythrocytes / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood; D006113:United Kingdom / Q000453:epidemiology; D014655:Vascular Resistance; D014664:Vasodilation
chemical_list: D015525:Fatty Acids, Omega-3; D014280:Triglycerides; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid