Scope
In contrast to well-characterized polyunsaturated fatty acid (PUFA) levels in serum, little is known regarding their downstream metabolic products. However, many of these compounds are lipid mediators with prominent roles during pro- and anti-inflammatory processes.
Methods and Results
In this double blind crossover study on asthmatics, shifts in serum levels of ω-3 and ω-6 PUFA-derived oxidized fatty acids (e.g., eicosanoids, oxylipins) were quantified following dietary fish oil supplementation. Serum was obtained from subjects following fasting at 3 occasions; 1) Prior to supplementation, 2) Following a 3-week supplement intake of either placebo or fish oil, and 3) Following a 3-week washout period with a subsequent 3-week period of either fish oil or placebo supplement. A total of 87 oxylipins representing cyclooxygenase (COX), lipoxygenase (LOX) and cytochrome P450 (CYP) metabolic pathways were screened via liquid chromatography-tandem mass spectrometry (LC-MS/MS). The primary alterations observed were in CYP- and 15-LOX-derived EPA- and CYP-derived DHA oxylipins.
Conclusion
The results indicate that intake of an ω-3 rich diet altars not only the PUFA ratio, but also the ratio of downstream oxylipins. These data further support that dietary manipulation with ω-3 PUFAs affects not only PUFA levels, but importantly also the downstream metabolic profile.