title: Validation of an equation predicting highly unsaturated fatty acid (HUFA) compositions of human blood fractions from dietary intakes of both HUFAs and their precursors.
abstract: Proportions of omega-3 (n-3) and omega-6 (n-6) in 20- and 22-carbon highly unsaturated fatty acids with 3 or more double bonds (HUFA) accumulated in tissue HUFA (e.g., the %n-6 in HUFA) are biomarkers reflecting intakes of n-6 and n-3 fatty acids. An empirical equation, referred to here as the Lands' Equation, was developed previously to use dietary intakes of n-6 and n-3 HUFA and their 18-carbon precursors to estimate the %n-6 in HUFA of humans. From the PubMed database, we identified clinical trials reporting (a) dietary intake of at least linoleic acid (18:2n-6) and alpha-linolenic acid (18:3n-3), and (b) the amounts of at least arachidonic acid (20:4n-6), eicosapentaenoic acid (20:5n-3), and docosahexaenoic acid (22:6n-3) in lipids of plasma, serum, or red blood cell. Linear regression analyses comparing reported and predicted %n-6 in HUFA gave a correlation coefficient of 0.73 (p<0.000000) for 34 studies with 92 subject groups. These results indicate that circulating HUFA compositions can be reliably estimated from dietary intake data that not only includes n-3 and n-6 HUFA consumption, but also includes consumption of 18 carbon n-3 and n-6 precursor fatty acids.
authors.affiliation: Seattle Children's Hospital for Pediatrics, USA. Electronic address: sarah.strandjord@seattlechildrens.org.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Strandjord
authors.affiliation: College Park, MD 20740, USA. Electronic address: wemlands@att.net.
authors.forename: Bill
authors.initials: B
authors.lastname: Lands
authors.affiliation: Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, 5625 Fishers Lane, Rm 3N-07, MSC 9410, Bethesda, MD 20892-2088, USA. Electronic address: jhibbeln@mail.nih.gov.
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Hibbeln
mesh_terms: D002986:Clinical Trials as Topic; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage* / Q000097:blood; D015525:Fatty Acids, Omega-3 / Q000097:blood*; D043371:Fatty Acids, Omega-6 / Q000097:blood*; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage* / Q000097:blood; D006801:Humans; D016014:Linear Models; D019787:Linoleic Acid / Q000097:blood; D008962:Models, Theoretical; D017962:alpha-Linolenic Acid / Q000097:blood
chemical_list: D004042:Dietary Fats, Unsaturated; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated; D017962:alpha-Linolenic Acid; D019787:Linoleic Acid
keywords: Blood lipids; HUFA balance; Highly unsaturated fatty acids (HUFA); Omega-3; Omega-6