title: Conversion of alpha-linolenic acid to palmitic, palmitoleic, stearic and oleic acids in men and women.
abstract: The purpose of this study was to determine whether adult humans can recycle carbon from alpha-linolenic acid (18:3n-3) into saturated (SFA) and monounsaturated (MUFA) fatty acids. Six men and six women consumed 700 mg [U-13C]-18:3n-3. Blood was collected over 21 days and breath over 24h. [13C]-labelled SFA and MUFA were detected in plasma phosphatidylcholine (PC) and triacylglycerol (TAG). Total labelled fatty acid incorporation into SFA and MUFA was five- and 25-fold greater in PC than TAG in men and women, respectively. [13C]-16:0 was the major labelled fatty acid in both fractions. Total [13C] incorporation into SFA and MUFA was 20% greater in men than women, and related positively (r(2) = 0.35, P<0.05) to the fractional recovery of labelled 18:3n-3 as 13CO2 on breath. These results suggest that the extent of partitioning towards beta-oxidation and carbon recycling may regulate the availability of 18:3n-3 for conversion to longer-chain fatty acids.
authors.affiliation: Institute of Human Nutrition, University of Southampton, Biomedical Sciences Building Bassett Crescent East, Southampton SO16 7PX, UK. g.c.burdge@soton.ac.uk
authors.forename: G C
authors.initials: GC
authors.lastname: Burdge
authors.forename: S A
authors.initials: SA
authors.lastname: Wootton
mesh_terms: D000328:Adult; D002245:Carbon Dioxide / Q000032:analysis; D002247:Carbon Isotopes; D005227:Fatty Acids / Q000032:analysis*; D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D019301:Oleic Acid; D010084:Oxidation-Reduction; D019308:Palmitic Acid; D010713:Phosphatidylcholines / Q000032:analysis; D012737:Sex Factors; D013229:Stearic Acids; D014280:Triglycerides / Q000032:analysis; D017962:alpha-Linolenic Acid / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated; D010713:Phosphatidylcholines; D013229:Stearic Acids; D014280:Triglycerides; D017962:alpha-Linolenic Acid; D002245:Carbon Dioxide; C008757:palmitoleic acid; D019301:Oleic Acid; D019308:Palmitic Acid