Role of a maternal diet high in linoleic acid on the plasma fatty acid composition in rat offspring

Abstract

Linoleic acid (LA) is a major omega-6 polyunsaturated fatty acid (PUFA) which is essential in our diet. LA is an important fatty acid for fetal growth and development and is transported from mother to fetus through the placenta. Dietary intake of LA has increased significantly in western societies primarily due to increased consumption of vegetable oils. Conversely, the consumption of alpha-linolenic acid (ALA), an omega-3 PUFA, has remained similar or decreased due to limited consumption of fish. Metabolites of omega-3 PUFAs such as docosahexaenoic (DHA) and eicosapentaenoic (EPA) have critical roles in fetal neural development and may influence brain function in later in life. The aim of this study is to investigate the effect of a maternal diet high in LA on offspring fatty acid composition at 40 days of age (adolescence). Female rats were fed with either low LA diet (LLA; 1.44% of energy from LA) or high LA (HLA; 6.21% of energy from LA) with matched ALA (0.3% of energy) for 10 weeks before pregnancy and during gestation. The pups were weaned at postnatal day 25 (PN25) and fed with either LLA or HLA diet (Four groups - LL, LH, HL, HH; first letter denotes maternal diet and second letter denotes post-weaning diet). The offspring were sacrificed at postnatal day 40 and biological samples were collected and stored at −80°C. The concentration of fatty acids in plasma was quantified using gas chromatography. Total omega-6 fatty acid (FA) and LA levels in plasma were significantly elevated in the offspring fed with HLA diet at weaning and offspring from dams fed with HLA (LH, HL, HH) compared to offspring from LLA dams fed with LLA at weaning (LL) both in male and female offspring. Total omega-3 FA was significantly decreased in offspring from HLA dams fed with HLA diet (HH) at weaning in comparison to offspring from LLA dams fed with LLA at weaning (LL). The concentration of ALA was significantly decreased in male offspring from HLA dams fed with HLA diet (HH) compared to HL offspring; however, there was no difference in female offspring. In addition, the plasma level of EPA was significantly decreased in male offspring fed with HLA diet at weaning (LH and HH) compared with LL offspring; however, there was no difference in female offspring. Moreover, DHA, an important omega-3 FA for brain development, was significantly decreased in HH offspring compared to LL offspring. Hence, the findings from the current study suggest that elevated LA in both maternal diet and weaning diet influence the plasma fatty acid composition in adolescent offspring in a rat model.