Tissue accretion and milk content of docosahexaenoic acid in female rats after supplementation with different docosahexaenoic acid sources.

BACKGROUND

Docosahexaenoic acid (DHA) is highly concentrated in the mammalian nervous and visual system. The fatty acid, which is required by the fetus and the newborn, is supplied by the mother from their tissue reservoirs. It has been suggested that mother's supplementation with DHA during pregnancy and even before pregnancy. Different sources of DHA are available for supplementation such as: single-cell algae triglycerides (TG), egg's yolk phospholipids (PL), DHA ethyl esther (EE), and sn-2 DHA monoacylglyceride (MG). We evaluated comparatively the effectiveness of these different DHA sources to produce tissue DHA accretion and to increase milk DHA content.

METHODS

Female Wistar rats fed a diet which provided no DHA, were daily supplemented by 40 days before mating (BM) and during the pregnancy with either TG, PL, EE, or MG to an amount which provided 8 mg/kg b.w. of DHA. Samples of blood plasma, erythrocytes, hepatic and adipose tissue were obtained from rats at the BM condition and after the delivery (AD), and milk samples were also obtained from the gastric content of the pups nursed by the rats at day 3, 11 and 20 of suckling. Samples were processed to assess DHA and arachidonic acid (AA) content by gas-chromatography.

RESULTS

TG, PL, EE, and MG supplementation produced a similar intestinal absorption of DHA as estimated from the plasma DHA at the BM condition. However, PL and MG supplementation produced a higher accretion of DHA into erythrocytes, hepatic, and adipose tissue than TG and EE supplementation at the BM condition. AA content was not modified by the different supplementing oils. A reduction of the DHA content of plasma, erythrocytes, hepatic and adipose tissue at the AD condition was observed, and a reduction of AA for the hepatic and adipose tissues was also observed, suggesting the importance of these tissues as DHA and AA reservoirs. Milk secretion from PL and MG supplemented rats showed a higher DHA content than secretion from TG- and EE-supplemented rats.

CONCLUSIONS

We conclude that PL and MG supplementation provides higher tissue DHA accretion and higher milk DHA content than TG and EE supplementation. However, we were not able to visualize the comparative advantages derived from PL vs. MG supplementation.