Brain docosahexaenoic acid (DHA) levels of young rats are related to alpha-linolenic acid (ALA) levels and fat matrix of the diet: impact of dairy fat

Bernadette Delplanque,Qin Du,Hassina Ould-Hamouda,Daniel Gripois,Pascale Leruyet,Pierre Carayon,Nicole Pages,Jean-Charles Martin,Genevieve Agnani

doi:10.1051/ocl.2011.0420

Abstract

Dososahexaenoate (DHA) is highly concentrated in mammalian nervous and visual systems and its deficiency during gestation, lactation and early life, could have dramatic impacts on brain functions and mental health. Achieving an appropriate DHA status in the neonatal brain is an important goal of neonatal nutrition. We evaluated how a-linolenic acid (ALA) provided by different dietary fat matrices improved DHA content in the brains of both young male and female rats. Young rats born from dams fed during gestation and lactation with a low ALA diet (0.4% of fatty acids) were subjected for 6 weeks after weaning to an anhydrous dairy fat blend-based diet that provided 1.5% ALA or to a palm oil blend-based diet that provided the same ALA level: either 1.5% ALA or 1.5% ALA and 0.12% DHA with 0.4% arachidonic acid (ARA). With each diet the n-6/ n-3 ratio was similar (10) to follow the values generally recommended for infant formula. Fatty acids analysis in whole brain showed that 1.5% ALA dairy fat blend was superior to both 1.5% ALA palm-oil blends, supplemented or not with dietary DHA, for increasing brain DHA. Females compared to males had significantly higher brain DHA with the 1.5% ALA palm-blend diet, but the dietary supplementation with DHA smoothed the differences by a specific increase of males DHA brain. In conclusion, dairy fat blend enriched with ALA appear to be an interesting strategy for achieving optimal DHA levels in the brain of post-weaning rats. Inclusion of dairy fat in infant formulas should be reconsidered.

Highlights

Docosahexaenoic acid (DHA;22:6n-3) and arachidonic acid (AA;20:4n-6) are highly concentrated in mammalian nervous and visual systems (Innis, 2007)
Linoleic acid (LA;18:2n-6) and alpha-linolenic acid (ALA;18:3n-3) are the precursors of long-chain n-6 and n-3 fatty acids, respectively. They can be synthesized from their respective precursor fatty acids (Mohrhauer and Holman, 1963), and, it has been shown in rats that supplementation of mothers with ALA or DHA leads to the same long-chain polyunsaturated fatty acids (LC-PUFA) accretion in maternal, fetal and newborn brains (Valenzuela et al, 2004; Childs et al, 2010b; Childs et al, 2011), synthesis could be insufficient to cover growth needs (Poumes-Ballihaut et al, 2001; Bowen and Clandinin, 2005; Plourde and Cunnane, 2007)
The main finding of our study is that an anhydrous dairy-fat-based diet with 1.5% ALA is more efficient than a palm oil blend providing the same ALA level and 0.12% added DHA and 0.4% arachidonic acid (ARA) for increasing brain DHA levels in postweaning rats

Summary

Introduction

Docosahexaenoic acid (DHA;22:6n-3) and arachidonic acid (AA;20:4n-6) are highly concentrated in mammalian nervous and visual systems (Innis, 2007). This animal was used in our study to compare the effects on brain fatty acids ( DHA) of dietary blends based on dairy fat instead of palm oil, which provide the same quantities of essential fatty acids.

Results

Conclusion