title: Effects of oils rich in eicosapentaenoic and docosahexaenoic acids on immune cell composition and function in healthy humans.
abstract: BACKGROUND
  Supplementation of the diet with fish oil, which is rich in the long-chain n-3 polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is reported to decrease several markers of immune function. However, whether EPA, DHA, or a combination of the 2 exerts these immunomodulatory effects is unclear.
  
  
  OBJECTIVE
  The objective of the study was to determine the effects of supplementation with an EPA-rich or DHA-rich oil on a range of immune outcomes representing key functions of human neutrophils, monocytes, and lymphocytes in healthy humans.
  
  
  METHODS
  In a placebo-controlled, double-blind, parallel study, 42 healthy subjects were randomly allocated to receive supplementation with either placebo (olive oil), EPA (4.7 g/d), or DHA (4.9 g/d) for 4 wk. Blood samples were taken before and after supplementation.
  
  
  RESULTS
  The fatty acid composition of plasma phospholipids and neutrophils was dramatically altered by supplementation with EPA or DHA, and the effects of EPA differed notably from those of DHA. DHA supplementation decreased T lymphocyte activation, as assessed by expression of CD69, whereas EPA supplementation had no significant effect. Neither the EPA-rich oil nor the DHA-rich oil had any significant effect on monocyte or neutrophil phagocytosis or on cytokine production or adhesion molecule expression by peripheral blood mononuclear cells.
  
  
  CONCLUSIONS
  Supplementation with DHA, but not with EPA, suppresses T lymphocyte activation, as assessed by expression of CD69. EPA alone does not, therefore, influence CD69 expression. No other marker of immune function assessed in this study was significantly affected by either EPA or DHA.
authors.affiliation: Hugh Sinclair Unit of Human Nutrition, School of Food Biosciences, University of Reading, United Kingdom.
authors.forename: Samantha
authors.initials: S
authors.lastname: Kew
authors.forename: Maria D
authors.initials: MD
authors.lastname: Mesa
authors.forename: Sabine
authors.initials: S
authors.lastname: Tricon
authors.forename: Richard
authors.initials: R
authors.lastname: Buckley
authors.forename: Anne M
authors.initials: AM
authors.lastname: Minihane
authors.forename: Parveen
authors.initials: P
authors.lastname: Yaqoob
mesh_terms: D000328:Adult; D000368:Aged; D016207:Cytokines / Q000096:biosynthesis; D004041:Dietary Fats / Q000276:immunology*; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000276:immunology*; D004311:Double-Blind Method; D004537:Eicosanoic Acids / Q000008:administration & dosage / Q000276:immunology*; D005395:Fish Oils / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects*; D008875:Middle Aged; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology; D010587:Phagocytosis / Q000187:drug effects
chemical_list: D016207:Cytokines; D004041:Dietary Fats; D004537:Eicosanoic Acids; D005395:Fish Oils; D004281:Docosahexaenoic Acids