Analysis of long-chain omega-3 fatty acid content in fish-oil supplements.
BACKGROUND
Omega-3 polyunsaturated fatty acids (long-chain omega-3 PUFA) have proved to be beneficial in atherosclerosis, arrhythmia and hypertriglyceridemia in several studies, which has led national and international societies to recommend an intake of 1 g/d long-chain omega-3 PUFA for anti-atherosclerotic and antiarrhythmic purposes or 2-4 g/d for a lipid lowering effect. Numerous preparations are marketed for supplementing western diet, which is low in long-chain omega-3 PUFA. Since these preparations vary in their long-chain omega-3 PUFA content, we tested nine commercially available products for their fatty acid composition.


METHODS
Nine commercially available omega-3 fatty acid supplements were analyzed using capillary gas chromatography to determine their fatty acid content.


RESULTS
The nine preparations showed huge differences, up to 63.7 +/- 1.58 mol% (P = 0.002), in their longchain omega-3 fatty acid content. Most of them failed to achieve the daily recommended dose of 1 g, even when administered at the highest dosage according to the manufacturer's recommendations. Eight of the preparations contained either equal or significantly greater amounts of long-chain omega-3 PUFA than denoted by the manufacturer; one preparation did not provide any information. The highest percentage of DHA and EPA was detected in Omacor(95.80 +/- 0.63%) and Percucor (76.8 +/- 7.109%).


CONCLUSIONS
Administering long-chain omega-3 fatty acid preparations may result in huge differences in terms of the actual amount ingested. It is therefore advisable to use the most standardized and purified products available.
Department of Internal Medicine, Clinical Division of General Internal Medicine, Medical University Innsbruck, Austria.
Tobias
T
Tatarczyk
Julia
J
Engl
Christian
C
Ciardi
Markus
M
Laimer
Susanne
S
Kaser
Karin
K
Salzmann
Ruth
R
Lenners
Josef R
JR
Patsch
Christoph F
CF
Ebenbichler
D001145:Arrhythmias, Cardiac / Q000517:prevention & control*; D050197:Atherosclerosis / Q000517:prevention & control*; D002849:Chromatography, Gas; D019587:Dietary Supplements / Q000032:analysis*; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000032:analysis*; D006801:Humans; D006949:Hyperlipidemias / Q000517:prevention & control*
D015525:Fatty Acids, Omega-3