The effect of maternal dietary fat content and n-6:n-3 ratio on offspring growth and hepatic gene expression in the rat.

Sally A V Draycott,Matthew J Elmes,Grace George,Beverly S Muhlhausler,Simon C Langley-Evans

doi:10.1017/s000711452000046x

Abstract

n-6 Fatty acids have been shown to exert pro-adipogenic effects, whereas n-3 fatty acids work in opposition. Increasing intakes of linoleic acid (LA; n-6) v. α-linolenic acid (ALA; n-3) in Western diets has led to the hypothesis that consumption of this diet during pregnancy may be contributing to adverse offspring health. This study investigated the effects of feeding a maternal dietary LA:ALA ratio similar to that of the Western diet (9:1) compared with a proposed 'ideal' ratio (about 1:1·5), at two total fat levels (18 v. 36 % fat, w/w), on growth and lipogenic gene expression in the offspring. Female Wistar rats were assigned to one of the four experimental groups throughout gestation and lactation. Offspring were culled at 1 and 2 weeks of age for sample collection. Offspring of dams consuming a 36 % fat diet were approximately 20 % lighter than those exposed to an 18 % fat diet (P < 0·001). Male, but not female, liver weight at 1 week was approximately 13 % heavier and had increased glycogen (P < 0·05), in offspring exposed to high LA (P < 0·01). Hepatic expression of lipogenic genes suggested an increase in lipogenesis in male offspring exposed to a 36 % fat maternal diet and in female offspring exposed to a low-LA diet, via increases in the expression of fatty acid synthase and sterol regulatory element-binding protein. Sexually dimorphic responses to altered maternal diet appeared to persist until 2 weeks of age. In conclusion, whilst maternal total fat content predominantly affected offspring growth, fatty acid ratio and total fat content had sexually dimorphic effects on offspring liver weight and composition.

Highlights

Accumulating evidence suggests that the nutritional environment experienced by an individual during fetal and early infant development has long-lasting impacts on their metabolic health (1).In the context of the global epidemic of obesity and nutritional excess, there has been considerable interest in determining the effects of maternal overnutrition on the metabolic health of the offspring
Protein intake was affected by dietary fat content only (P
This study has demonstrated that altering the fat content and/or LA:ALA ratio of the maternal diet during pregnancy and lactation resulted in significant alteration in the circulating fatty acid profile of dams in the absence of any significant effects on maternal bodyweight or body composition

Summary

Introduction

In the context of the global epidemic of obesity and nutritional excess, there has been considerable interest in determining the effects of maternal overnutrition on the metabolic health of the offspring. The majority of these studies have utilised animal models and have consistently reported that maternal high-fat feeding during pregnancy has detrimental effects on the metabolic health of both the mother and her offspring (2,3). There is increasing evidence, that the impact of a high-fat diet on the metabolic health of the offspring depends on the amount of fat in the diet, and on the fatty acid composition (4,5).

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