title: Gamma-linolenic acid does not augment long-chain polyunsaturated fatty acid omega-3 status.
abstract: Augmentation of long chain polyunsaturated omega3 fatty acid (LCPUFA omega3) status can be reached by consumption of fish oil or by improvement of the conversion of alpha-linolenic acid (ALA) to LCPUFA omega3. Since gamma-linolenic acid (GLA) might activate the rate-limiting delta-6 desaturation, we investigated whether GLA augments LCPUFA omega3 status. Eight adults received 1.4 g GLA for 4 weeks and subsequently 2.2 g ALA+1.4 g GLA daily during another 4 weeks. Another seven adults received a daily oral dose of 2.2 g ALA for 4 weeks, and subsequently 2.2 g ALA+1.4 g GLA during another 4 weeks. ALA, or ALA+GLA, did not significantly augment EPA and DHA contents. We conclude that the LCPUFA omega3 status can not be improved by supplementation of low dose GLA, neither by co-supplementation of ALA. Poor conversion of ALA to LCPUFA omega3 may be caused by preferential beta-oxidation of ALA, negative feedback of arachidonic acid from the omnivorous diet, or by the low dietary ALA/LA ratio.
authors.affiliation: Central Laboratory for Clinical Chemistry, University Hospital Groningen, The Netherlands. d.a.j.brouwer@lab.azg.nl
authors.forename: D A
authors.initials: DA
authors.lastname: Brouwer
authors.forename: Y
authors.initials: Y
authors.lastname: Hettema
authors.forename: J J
authors.initials: JJ
authors.lastname: van Doormaal
authors.forename: F A
authors.initials: FA
authors.lastname: Muskiet
mesh_terms: D000328:Adult; D001792:Blood Platelets / Q000737:chemistry / Q000187:drug effects; D002788:Cholesterol Esters / Q000097:blood; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000737:chemistry / Q000187:drug effects; D005227:Fatty Acids / Q000032:analysis / Q000097:blood / Q000737:chemistry; D015525:Fatty Acids, Omega-3 / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D014280:Triglycerides / Q000097:blood / Q000737:chemistry; D017965:gamma-Linolenic Acid / Q000494:pharmacology*
chemical_list: D002788:Cholesterol Esters; D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D014280:Triglycerides; D017965:gamma-Linolenic Acid