Omega-3 supplementation increases C-EPA but not C-DHA kinetics in healthy older adults after C-DHA single dose intake: A secondary analysis.

OBJECTIVE

To investigated whether post supplementation, C-DHA is less incorporated into plasma phospholipids (PL) and triglycerides (TG) compared to pre-supplementation considering that these are the two most prominent delivery pools of DHA to tissues.

METHODOLOGY

Plasma samples from twenty healthy men and women, matched for age and body mass index, were analyzed. Participants received a single oral dose of 40 mg C-DHA in 2 kinetic studies: 1 prior to and 1 during the last month of supplementation with 3.2 g/day of ω3 PUFA. C enrichment analyses were performed on plasma samples at baseline, 4, 6, 24 hours, 7 days, and 28 days post-tracer intake. Lipids were extracted, and PL and TG were separated by solid-phase extraction. Quantification of carbon-13 eicosapentaenoic acid (C-EPA) and C-DHA was performed using gas chromatography-mass spectrometry (GC-MS).

RESULTS

The area under the curve (AUC) for C-DHA in PL and TG did not show statistically significant differences before and during supplementation. However, the AUC for C-EPA in PL and TG increased by 45% and 48% with supplementation, respectively. This finding was unexpected, as our previous analysis indicated a 60% reduction in plasma C-DHA levels during supplementation, accompanied by increased β-oxidation. Additionally, there were statistically significant time × gender interactions for C-EPA and C-DHA in plasma PL (P < 0.0001), with women exhibiting 90% and 139% higher levels of C-EPA and C-DHA over time, respectively. No time × gender interactions were observed for C-EPA and C-DHA in plasma TG, although independent time and gender effects were present. Furthermore, there was a time × body mass index interaction for C-EPA in PL only.

CONCLUSION

This secondary analysis suggests that after supplementation with ω3 PUFA, DHA metabolism is stable while EPA metabolism may be slowed due to factors such as DHA inhibition of EPA elongation and/or reduced plasma clearance, which may indicate the tissues needs for DHA are being met.