title: Effects of safflower oil and evening primrose oil in men with a low dihomo-gamma-linolenic level.
abstract: Low levels of essential polyunsaturated fatty acids of the n-6 series are associated with coronary heart disease. Linoleic acid, but not gamma-linolenic acid requires the activity of delta 6-desaturase for its conversion to dihomo-gamma-linolenic and arachidonic acid. Evening primrose oil (EPO) and safflower oil (SO) are rich in linoleic acid, but EPO contains also 9% gamma-linolenic acid. The effect of EPO (10, 20 and 30 ml/day) and SO (20 ml/day) for 4 months on the deposition of linoleic acid metabolites in adipose tissue of 4 groups of 6-9 men with low adipose dihomo-gamma-linolenic acid was examined. EPO but not SO increased adipose dihomo-gamma-linolenic acid level from 0.080 +/- 0.005% to 0.101 +/- 0.005% (P less than 0.01; 20 ml/day for 4 months). Adipose dihomo-gamma-linolenic/linoleic acid ratio increased with EPO from 0.99 +/- 0.16 X 10(2) to 1.13 +/- 0.14 X 10(2) and fell on SO from 1.04 +/- 0.10 X 10(2) to 0.90 +/- 0.07 X 10(2) (P less than 0.01). Similar qualitative changes in the relative amount of dihomo-gamma-linolenic acid in serum triglyceride and cholesteryl ester fractions were observed. At the dose of 20 ml/day, SO and EPO did not differ in their effect on serum cholesterol (7.13 +/- 0.43 vs. 7.33 +/- 0.42 mmol/l (NS)), LDL-cholesterol (5.10 +/- 0.32 vs. 4.88 +/- 0.46 mmol/l (NS)) nor did the 2 oils differ in their effect on HDL-cholesterol. These results suggest that linoleic acid is not readily converted to dihomo-gamma-linolenic acid due to a low activity of delta 6-desaturase in these highly selected men. EPO was not an effective hypocholesterolaemic agent in this study.
authors.affiliation: Cardiovascular Research Unit, University of Edinburgh, Scotland, U.K.
authors.forename: R D
authors.initials: RD
authors.lastname: Abraham
authors.forename: R A
authors.initials: RA
authors.lastname: Riemersma
authors.forename: R A
authors.initials: RA
authors.lastname: Elton
authors.forename: C
authors.initials: C
authors.lastname: Macintyre
authors.forename: M F
authors.initials: MF
authors.lastname: Oliver
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000097:blood / Q000378:metabolism*; D000273:Adipose Tissue / Q000378:metabolism; D000328:Adult; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000097:blood / Q000378:metabolism; D005228:Fatty Acids, Essential / Q000494:pharmacology*; D005231:Fatty Acids, Unsaturated / Q000097:blood / Q000378:metabolism*; D006801:Humans; D000960:Hypolipidemic Agents / Q000494:pharmacology*; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000097:blood / Q000378:metabolism; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D031665:Oenothera biennis; D010938:Plant Oils / Q000494:pharmacology*; D012450:Safflower Oil / Q000494:pharmacology*; D017965:gamma-Linolenic Acid
chemical_list: D001095:Arachidonic Acids; D005228:Fatty Acids, Essential; D005231:Fatty Acids, Unsaturated; D000960:Hypolipidemic Agents; D008041:Linoleic Acids; D008055:Lipids; D010938:Plant Oils; D016718:Arachidonic Acid; C028498:evening primrose oil; D017965:gamma-Linolenic Acid; D012450:Safflower Oil; D019787:Linoleic Acid; D015126:8,11,14-Eicosatrienoic Acid