Validation of an equation predicting highly unsaturated fatty acid (HUFA) compositions of human blood fractions from dietary intakes of both HUFAs and their precursors

• Published in: Prostaglandins, leukotrienes and essential fatty acids Vol. 136; pp. 171 - 176
• Main Authors: Strandjord, Sarah E., Lands, Bill, Hibbeln, Joseph R.
• Format: Journal Article
• Language: English
• Published: Scotland Elsevier Ltd 01.09.2018
• Subjects: Advanced Basic Science; alpha-Linolenic Acid - blood; Blood lipids; Clinical Trials as Topic; Dietary Fats, Unsaturated - administration & dosage; Dietary Fats, Unsaturated - blood; Endocrinology & Metabolism; Fatty Acids, Omega-3 - blood; Fatty Acids, Omega-6 - blood; Fatty Acids, Unsaturated - administration & dosage; Fatty Acids, Unsaturated - blood; Highly unsaturated fatty acids (HUFA); HUFA balance; Humans; Linear Models; Linoleic Acid - blood; Models, Theoretical; Omega-3; Omega-6; NR; HUFA balance; S-PL; n-6 in HUFA; SDA; RBC; S-TL; n-3; n-6; RBC-PL; Blood lipids; Highly unsaturated fatty acids (HUFA); AA; PUFA; Omega-6; en; HUFA; Omega-3; EPA+DHA in RBC; P-TL; LA; ALA; EPA; DHA; P-PL; GLA; serum phospholipids; highly unsaturated fatty acids; plasma total lipids; polyunsaturated fatty acids; serum total lipids; red blood cell; omega-3; omega-6; docosahexaneoic acid; not reported; arachidonic acid; percentage of EPA and DHA in total fatty acids of red blood cell; alpha-linolenic acid; plasma phospholipids; percent of energy; linoleic acid; the percentage of omega-6 highly unsaturated fatty acids in total tissue HUFA; eicosapentaenoic acid; red blood cell phospholipids; stearidonic acid; gamma-linolenic acid
• ISSN: 0952-3278; 1532-2823; 1532-2823
• DOI: 10.1016/j.plefa.2017.03.005

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. •Omega-3/omega-6 highly unsaturated fatty acids (HUFA) are disease risk biomarkers.•Precursor dietary fats are not typically included in estimating n-3 and n-6 HUFAs.•Reliable HUFA biomarkers estimates require both dietary precursor fats and HUFAs.