Oxidation of an oil rich in docosahexaenoic acid compared to linoleic acid in lactating women.

Background: We studied the oxidation of an oil rich in docosahexaenoic acid (DHA; DHASCO®) in lactating mothers receiving a dietary DHA supplement or a placebo. The results were compared with the oxidation of linoleic acid. Methods: Breast-feeding mothers received a dietary supplement (DHASCO; 200 mg DHA/day, n = 5) or a placebo (n = 5) for 14 days. Six weeks post partum all 10 mothers received a single dose of 2 mg/kg body weight uniformly 13C-labeled DHASCO. In a previously reported study 6 mothers received 1 mg/kg body weight uniformly 13C-labeled linoleic acid. Breath samples were collected over 48 h after tracer application. The total CO2 production was measured by indirect calorimetry and the 13C isotopic enrichment of labeled CO2 by isotopic ratio mass spectrometry. Results: The oxidation of 13C-labeled DHASCO in the supplemented and placebo groups was similar. Maximal 13C enrichment was reached earlier in the group receiving 13C-DHASCO (median 1.0 vs. 3.0 h in the linoleic acid group). The cumulative 13C recovery in breath was higher in the DHASCO versus the linoleic acid group until 10 h after tracer application and comparable thereafter. Conclusions: The difference in oxidation of DHASCO versus linoleic acid after tracer ingestion might be partly due to a faster absorption and oxidation of shorter chain saturated fatty acids contained in DHASCO. The cumulative oxidation of DHASCO and linoleic acid 24 and 48 h after tracer ingestion is similar.