Key Findings
Oxylipins refer to a group of natural oxygenated substances formed from fatty acids. In humans, most are coined eicosanoids. Several oxylipins produce inflammation in humans. This study shows that flaxseed reduces several of these (5-HETE, 9,10,13-TriHOME and 9,12,13-TriHOME) in older people resulting in levels more similar to those of younger people. Also oxylipin profiles were altered in young subjects with levels of those stimulating neutrophil chemotaxis showing a significant decline. This is the first study to report differences in serum oxylipin profiles based upon age and gender. Following dietary flaxseed supplementation, positive changes in plasma oxylipin profiles were found in young and older subjects in particular in reductions in those oxylipins that cause neutrophil chemotaxis and inflammation.
ABSTRACT
BACKGROUND AND AIMS: Oxylipins, including eicosanoids, are highly bioactive molecules endogenously produced from polyunsaturated fatty acids. Oxylipins play a key role in chronic disease progression. It is possible, but unknown, if oxylipin concentrations change with the consumption of functional foods or differ with subject age.
METHODS: Therefore, in a parallel comparator trial, 20 healthy individuals were recruited into a younger (19-28years) or older (45-64years) age group (n=10/group). Participants ingested one muffin/day containing 30g of milled flaxseed (6g alpha-linolenic acid) for 4weeks. Plasma oxylipins were isolated through solid phase extraction, analyzed with HPLC-MS/MS targeted lipidomics, and quantified with the stable isotope dilution method.
RESULTS: At baseline, the older group exhibited 13 oxylipins ≥2-fold the concentration of the younger group. Specifically, pro-inflammatory oxylipins 5-hydroxyeicosatetraenoic acid, 9,10,13-trihydroxyoctadecenoic acid, and 9,12,13-trihydroxyoctadecenoic acid were significantly greater in the older (1.1±0.23nM, 5.6±0.84nM, and 4.5±0.58nM, respectively) versus the younger group (0.34±0.12nM, 3.5±0.33nM, and 3.0±0.24nM, respectively) (p<0.05). After 4weeks of flaxseed consumption the number of oxylipins that were ≥2-fold higher in the older versus the younger group was reduced to 3. 5-Hydroxyeicosatetraenoic acid, 9,10,13-trihydroxyoctadecenoic acid, and 9,12,13-trihydroxyoctadecenoic acid decreased in the older group to concentrations equivalent to the younger group after flaxseed consumption.
CONCLUSION: These data suggest a potential role for oxylipins in the aging process and how nutritional interventions like flaxseed can beneficially disrupt these biological changes associated with inflammation and aging.
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