title: Postprandial Plasma Phospholipids in Men Are Influenced by the Source of Dietary Fat.
abstract: BACKGROUND
  Postprandial lipemia represents a risk factor for chronic diseases, including type 2 diabetes. Little is known about the effect of dietary fat on the plasma lipidome in the postprandial period.
  
  
  OBJECTIVE
  The objective of this study was to assess the effect of dairy fat and soy oil on circulating postprandial lipids in men.
  
  
  METHODS
  Men (40-60 y old, nonsmokers; n = 16) were randomly assigned in a crossover design to consume 2 breakfast meals of dairy-based or soy oil-based foods. The changes in the plasma lipidome during the 4-h postprandial period were analyzed with electrospray ionization tandem mass spectrometry and included 316 lipid species in 23 classes and subclasses, representing sphingolipids, phospholipids, glycerolipids, and sterols.
  
  
  RESULTS
  Nonparametric Friedman tests showed significant changes in multiple plasma lipid classes, subclasses, and species in the postprandial period after both dairy and soy meals. No difference was found in triglyceridemia after each meal. However, 6 endogenous lipid classes increased after dairy but decreased after soy (P < 0.05), including ether-linked phospholipids and plasmalogens and sphingomyelin (not present in soy), dihexosylceramide, and GM3 ganglioside. Phosphatidylcholine and phosphatidylinositol were not affected by the soy meal but were significantly elevated after the dairy meal (8.3% and 16%, respectively; P < 0.05).
  
  
  CONCLUSIONS
  The changes in postprandial plasma phospholipids in men relate to the diet composition and the relative size of the endogenous phospholipid pools. Despite similar lipemic responses as measured by changes in triglyceride concentrations, the differential responses to dairy and soy meals derived through lipidomic analysis of phospholipids suggest differences in the metabolism of soybean oil and dairy fat. The increased concentrations of plasmalogens, with potential antioxidant capacity, in the postprandial period after dairy but not soy meals may represent a further important difference in the response to these sources of fat. The trial was registered at www.anzctr.org.au as ACTRN12610000562077.
authors.affiliation: Metabolomics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Australia; and peter.meikle@bakeridi.edu.au.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Meikle
authors.affiliation: Metabolomics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Australia; and.
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Barlow
authors.affiliation: Metabolomics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Australia; and.
authors.forename: Natalie A
authors.initials: NA
authors.lastname: Mellett
authors.affiliation: Metabolomics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Australia; and.
authors.forename: Piyushkumar A
authors.initials: PA
authors.lastname: Mundra
authors.affiliation: School of Medicine, Deakin University, Geelong, Australia.
authors.forename: Maxine P
authors.initials: MP
authors.lastname: Bonham
authors.affiliation: School of Medicine, Deakin University, Geelong, Australia.
authors.forename: Amy
authors.initials: A
authors.lastname: Larsen
authors.affiliation: School of Medicine, Deakin University, Geelong, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Cameron-Smith
authors.affiliation: School of Medicine, Deakin University, Geelong, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Sinclair
authors.affiliation: Metabolomics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Australia; and.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Nestel
authors.affiliation: Metabolomics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Australia; and.
authors.forename: Gerard
authors.initials: G
authors.lastname: Wong
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D018592:Cross-Over Studies; D003611:Dairy Products; D003924:Diabetes Mellitus, Type 2 / Q000097:blood; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage*; D005227:Fatty Acids / Q000032:analysis; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood / Q000150:complications; D007328:Insulin / Q000097:blood; D008297:Male; D062407:Meals; D008875:Middle Aged; D010743:Phospholipids / Q000097:blood*; D019518:Postprandial Period; D012189:Retrospective Studies; D045730:Soy Foods; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D004041:Dietary Fats; D005227:Fatty Acids; D007328:Insulin; D010743:Phospholipids; D014280:Triglycerides
keywords: dairy; humans; lipidomics; mass spectrometry; phospholipids; soy