Postnatal deficiency of essential fatty acids in mice results in resistance to diet-induced obesity and low plasma insulin during adulthood

Lipid Quality in Infant Nutrition: Current Knowledge and Future Opportunities

Dietary lipids are key for infants to not only meet their high energy needs but also fulfill numerous metabolic and physiological functions critical to their growth, development, and health. The lipid composition of breast milk varies during lactation and according to the mother's diet, whereas the lipid composition of infant formulae varies according to the blend of different fat sources. This report compares the compositions of lipids in breast milk and infant formulae, and highlights the roles of dietary lipids in term and preterm infants and their potential biological and health effects. The major differences between breast milk and formulae lie in a variety of saturated fatty acids (such as palmitic acid, including its structural position) and unsaturated fatty acids (including arachidonic acid and docosahexaenoic acid), cholesterol, and complex lipids. The functional outcomes of these differences during infancy and for later child and adult life are still largely unknown, and some of them are discussed, but there is consensus that opportunities exist for improvements in the qualitative lipid supply to infants through the mother's diet or infant formulae. Furthermore, research is required in several areas, including the needs of term and preterm infants for long-chain polyunsaturated fatty acids, the sites of action and clinical effects of lipid mediators on immunity and inflammation, the role of lipids on metabolic, neurological, and immunological outcomes, and the mechanisms by which lipids act on short- and long-term health.

Different fatty acid pattern in breast milk of obese compared to normal-weight mothers

INTRODUCTION

The aim of this study was to investigate the fatty acid (FA) pattern in breast milk of obese mothers and their neonates' plasma compared to those of normal weight mothers.

PATIENTS AND METHODS

This was an observational study of 41 obese and 41 normal weight pregnant women. Twenty-nine obese women participating in a weight reduction program were investigated for comparison. FAs were analyzed in breast milk collected at 3 and 10 days and one and two months postnatally and in infant's plasma 3 days after birth.

RESULTS AND CONCLUSIONS

The concentration of long-chain n-3 FA were lower and the ratio n-6/n-3 FA higher in neonates and in consecutive samples of breast milk of obese mothers compared to normal weight mothers. The obese mothers that participated in an intervention program with general dietary advice had FA concentrations approaching that of the normal-weight mothers. The study indicates importance of dietary advice in pregnancy.

Motor, mental and behavioral developments in infancy are associated with fatty acid pattern in breast milk and plasma of premature infants

The objective of this study was to investigate any association between infants' early development and PUFA concentrations in early breast milk and infants' plasma phospholipids at 44 weeks gestational age. Fifty-one premature infants were included. The quality of general movement was assessed at 3 months, and motor, mental and behavioral development at 3, 6, 10 and 18 months corrected age using Bayley's Scales of Infant Development (BSID-II). Linoleic acid, the major n-6/n-3 FA ratios, Mead acid and the EFA deficiency index in early breast milk were negatively associated with development up to 18 months of age. DHA and AA, respectively, in infants' plasma phospholipids was positively, but the AA/DHA ratio negatively, associated with development from 6 to 18 months of age. Our data suggest that the commonly found high n-6 concentration in breast milk is associated with less favorable motor, mental and behavioral development up to 18 months of age.

Postnatal essential fatty acid deficiency in mice affects lipoproteins, hepatic lipids, fatty acids and mRNA expression

We have previously reported that essential fatty acid deficiency (EFAD) during suckling in mice resulted in an adult lean phenotype and a resistance to diet-induced obesity. We now hypothesized that postnatal EFAD would cause long-term effects on lipid metabolism. C57BL/6 mice were fed an EFAD or a control diet from the 16th day of gestation and throughout lactation. The pups were weaned to standard diet (STD) and at 15 weeks of age given either high fat diet (HFD) or STD. Lipoprotein profiles, hepatic lipids, fatty acids and mRNA expression were analyzed in 3-week-old and 25-week-old offspring. At weaning, the EFAD pups had higher cholesterol levels in both plasma and liver and 6-fold higher concentrations of hepatic cholesterol esters than control pups. Adult EFAD offspring had higher levels of hepatic cholesterol and linoleic acid, but lower levels of dihomo-γ-linolenic acid and Pparg mRNA expression in the liver. In addition, HFD fed EFAD offspring had lower plasma total cholesterol, lower hepatic triglycerides and lower liver weight compared to controls fed HFD. In conclusion, early postnatal EFAD resulted in short-term alterations with increased hepatic cholesterol accumulation and long-term protection against diet-induced liver steatosis and hypercholesterolemia.

ISSFAL 2010 dinner debate: healthy fats for healthy hearts - annotated report of a scientific discussion

BACKGROUND/AIMS

The importance of reducing saturated fatty acid intake to prevent cardiovascular disease and recommended intakes for omega-6 polyunsaturated fatty acids (PUFAs) are controversial. Therefore, experts debated these topics at the biennial meeting of the International Society for the Study of Fatty Acids and Lipids (ISSFAL), in May 2010.

METHODS

Debate transcripts, debaters' and discussants' reviews and literature citations were the basis of this report.

RESULTS

Participants agreed that saturates per se are not 'bad', but that dietary recommendations should emphasize the substitution of unsaturates for part of the saturates. Evidence supporting omega-6 PUFA intakes of 5 to 10% is mixed; some interpret the overall data from diverse studies as consistent with a reduction in the risk of cardiovascular mortality and events. Others assert that randomized controlled trial data suggest that higher intakes of omega-6 PUFAs are not associated with lower risk of heart disease, or may even increase it.

CONCLUSIONS

All agreed that a 5-year randomized controlled trial comparing the effects of historically low (2%) with currently high (7.5%) linoleic acid intakes on cardiac endpoints would address the knowledge gap about the effects of different omega-6 PUFA intakes on the risk of heart disease.