title: Effects of docosahexaenoic acid supplementation on PUFA levels in red blood cells and plasma.
abstract: Polyunsaturated fatty acids (PUFA) are metabolized in a complex network of elongation, desaturation and beta oxidation.
  
  
  
  The short (1 and 3 wk), and long term (6 and 12 wk) effect of 1076mg/d docosahexaenoic acid (DHA, free of eicosapentaenoic acid (EPA)) on (absolute) PUFA concentrations in plasma and red blood cells (RBC) of 12 healthy men (mean age 25.1±1.5 years) was investigated.
  
  
  
  RBC DHA concentrations significantly (p<0.001) increased from 28±1.6µg/mL to 38±2.0µg/mL (wk 1), 52±3.3µg/mL (wk 3), 68±2.6µg/mL (wk 6), and 79±3.5µg/mL (wk 12). Arachidonic acid (AA) concentrations declined in response to DHA treatment, while the effect was more pronounced in plasma (wk 0: 183±9.9µg/mL, wk 12: 139±8.0µg/mL, -24%, p<0.001) compared to RBC (wk 0: 130±3.7µg/mL, wk 12: 108±4.0µg/mL, -16%, p=0.001). Furthermore, an increase of EPA concentrations in plasma (wk 0: 15±1.5µg/mL, wk 1:19±1.6µg/mL, wk 3: 27±2.3µg/mL, wk 6: 23±1.2µg/mL, wk 12: 25±1.7µg/mL, p<0.001) and RBC (wk 0: 4.7±0.33µg/mL, wk 1: 6.7±1.3µg/mL, wk 3: 8.0±0.66µg/mL, wk 6: 6.9±0.44µg/mL, wk 12: 6.7±0.45µg/mL, n.s.) was observed suggesting a retroconversion of DHA to EPA.
  
  
  
  Based on PUFA concentrations we showed that DHA supplementation results in increased EPA levels, whereas it is not known if this impacts the formation of EPA-derived lipid mediators. Furthermore, shifts in the entire PUFA pattern after supplementation of EPA or DHA should be taken into account when discussing differential physiological effects of EPA and DHA.
authors.affiliation: Institute of Food Science and Human Nutrition, Leibniz University Hannover, Germany. Electronic address: Schuchardt@nutrition.uni-hannover.de.
authors.forename: Jan Philipp
authors.initials: JP
authors.lastname: Schuchardt
authors.affiliation: Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover, Germany.
authors.forename: Annika I
authors.initials: AI
authors.lastname: Ostermann
authors.affiliation: Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover, Germany.
authors.forename: Lisa
authors.initials: L
authors.lastname: Stork
authors.affiliation: Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover, Germany.
authors.forename: Laura
authors.initials: L
authors.lastname: Kutzner
authors.affiliation: Institute of Food Science and Human Nutrition, Leibniz University Hannover, Germany.
authors.forename: Heike
authors.initials: H
authors.lastname: Kohrs
authors.affiliation: Institute of Food Science and Human Nutrition, Leibniz University Hannover, Germany.
authors.forename: Theresa
authors.initials: T
authors.lastname: Greupner
authors.affiliation: Institute of Food Science and Human Nutrition, Leibniz University Hannover, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hahn
authors.affiliation: Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover, Germany; Institute of Food Chemistry, University of Wuppertal, Germany.
authors.forename: Nils Helge
authors.initials: NH
authors.lastname: Schebb
mesh_terms: D000328:Adult; D019587:Dietary Supplements; D004281:Docosahexaenoic Acids / Q000008:administration & dosage*; D004334:Drug Administration Schedule; D015118:Eicosapentaenoic Acid / Q000097:blood; D004912:Erythrocytes / Q000737:chemistry*; D005231:Fatty Acids, Unsaturated / Q000097:blood*; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D010949:Plasma / Q000737:chemistry*; D055815:Young Adult
chemical_list: D005231:Fatty Acids, Unsaturated; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid
keywords: EPA; LC n3 PUFA; Metabolism; Purified DHA; Retroconversion