Paradoxical effects of essential fatty acid supplementation on lipid profiles and sweat electrolytes in cystic fibrosis.
Supplements of evening primrose oil (Oenothera biennis), which contains at least 72% linoleic (18:2n-6) and 7% gamma-linolenic (18:3 n-6) acids (expressed as % fatty acid methyl esters) were given to sixteen cystic fibrosis patients for a period of 12 months. Clinical observations showed no significant changes in patients' weights or respiratory function throughout. Linoleic acid levels in plasma and erythrocyte membranes increased significantly during the first 6 months but this increase was not sustained at its initial level. After supplementation was discontinued reversion to baseline (low) levels occurred within 4 months. Levels of plasma prostaglandins (PG) and urinary PG metabolites varied among individuals over a wide range, and urinary PGF2 alpha metabolites fell during the supplementation. There was a significant fall in sweat sodium concentrations after 6 weeks of supplementation, but sweat chloride was unchanged. It is not known whether the effect of essential fatty acids on sweat Na+ reflects changes in cell membrane conformation or if there is a direct effect on Na+ pump activity.
Department of Child Health, University of Wales College of Medicine, Heath Park, Cardiff.
J A
JA
Dodge
J M
JM
Custance
M C
MC
Goodchild
S C
SC
Laing
M
M
Vaughan
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002712:Chlorides / Q000378:metabolism; D002986:Clinical Trials as Topic; D003550:Cystic Fibrosis / Q000178:diet therapy* / Q000378:metabolism; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D004573:Electrolytes / Q000378:metabolism*; D005228:Fatty Acids, Essential / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008041:Linoleic Acids / Q000097:blood; D008055:Lipids / Q000097:blood*; D008297:Male; D031665:Oenothera biennis; D010938:Plant Oils; D012964:Sodium / Q000378:metabolism; D013542:Sweat / Q000378:metabolism*; D017965:gamma-Linolenic Acid
D002712:Chlorides; D004042:Dietary Fats, Unsaturated; D004573:Electrolytes; D005228:Fatty Acids, Essential; D008041:Linoleic Acids; D008055:Lipids; D010938:Plant Oils; C028498:evening primrose oil; D017965:gamma-Linolenic Acid; D012964:Sodium