Metabolism of stearidonic acid in human subjects: comparison with the metabolism of other n-3 fatty acids.
BACKGROUND
For many persons who wish to obtain the health benefits provided by dietary n-3 fatty acids, daily ingestion of fish or fish oil is not a sustainable long-term approach. To increase the number of sustainable dietary options, a land-based source of n-3 fatty acids that is effective in increasing tissue concentrations of the long-chain n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is required.


OBJECTIVE
The objective of the study was to examine the ability of dietary stearidonic acid (SDA) to increase tissue concentrations of EPA and DHA in healthy human subjects and to compare the effectiveness of SDA with that of the n-3 fatty acids alpha-linolenic acid (ALA) and EPA.


METHODS
Encapsulated SDA, ALA, or EPA was ingested daily in doses of 0.75 g and then 1.5 g for periods of 3 wk each by healthy male and postmenopausal female subjects (n = 15/group) in a double-blind, parallel-group design.


RESULTS
Dietary SDA increased EPA and docosapentaenoic acid concentrations but not DHA concentrations in erythrocyte and in plasma phospholipids. The relative effectiveness of the tested dietary fatty acids in increasing tissue EPA was 1:0.3:0.07 for EPA:SDA:ALA.


CONCLUSIONS
Vegetable oils containing SDA could be a dietary source of n-3 fatty acids that would be more effective in increasing tissue EPA concentrations than are current ALA-containing vegetable oils. The use of SDA-containing oils in food manufacture could provide a wide range of dietary alternatives for increasing tissue EPA concentrations.
James
Michael J
MJ
Rheumatology Unit, Royal Adelaide Hospital, Adelaide, Australia. michael.james@adelaide.edu.au
Ursin
Virginia M
VM
Cleland
Leslie G
LG
D000293:Adolescent; D000328:Adult; D000368:Aged; D016207:Cytokines / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D019587:Dietary Supplements; D004281:Docosahexaenoic Acids / Q000097:blood / Q000493:pharmacokinetics*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D015118:Eicosapentaenoic Acid / Q000097:blood / Q000493:pharmacokinetics*; D015525:Fatty Acids, Omega-3 / Q000378:metabolism / Q000493:pharmacokinetics* / Q000494:pharmacology; D005231:Fatty Acids, Unsaturated / Q000097:blood; D005260:Female; D005395:Fish Oils / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D014018:Tissue Distribution; D017962:alpha-Linolenic Acid / Q000008:administration & dosage / Q000378:metabolism
D016207:Cytokines; D015525:Fatty Acids, Omega-3; D005231:Fatty Acids, Unsaturated; D005395:Fish Oils; D017962:alpha-Linolenic Acid; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid; C026219:docosapentaenoic acid; C062895:stearidonic acid