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Polyunsaturated fatty acid (PUFA) composition data of the breast milk are rare but essential for assessing the adequate intake of fatty acids in the newborn and possibly directing the mother to a suitable diet or even supplementation with essential fatty acids. The raw data for lactating women from the national study on individual food consumption 2006-2007 (INCA 2) were combined with the French food composition table (Ciqual 2013) to assess their fatty acid intakes. Although this is a limited number of subjects, these data are still interesting to analyze and compare with current Anses recommendations. According to these results, omega 3 PUFA consumption is not sufficient for the purposes of the Recommended Dietary Intakes (RDI). In addition, it has been shown that the fatty acid composition of breast milk is a proven marker of dietary lipid consumption and a good reflection of the consumption's level of omega-6 and omega-3 PUFAs. Epidemiological data on quantity and quality of lipids consumed in France are rare. In the context of different observational and interventional studies conducted on breast milk, ITERG has been able to estimate the evolution of French food habits for nearly 17 years. A synthesis work has taken over all the data acquired during 3 clinical studies carried out between 1997 and 2014. This synthesis showed a positive evolution of the proportions in omega-3 PUFA in 17 years (1997-2014). However, the proportions of alpha-linolenic acid (ALA) and docosahexaenoic acid (DHA) in breast milk remain below nutritional recommendations for the newborn.

Summary Background The French National survey INCA2 pointed out that the majority of the French population (children, adolescents, adults and elderly) ingest low quantities of n-3 polyunsaturated fatty acid (PUFA) in the form of both precursor (alpha-linolenic acid, ALA) and long-chain (mainly docosahexaenoic acid, DHA). However, we don't know whether such inadequate n-3 PUFA consumption is also found again in pregnant and lactating women. Methods Dietary lipid and PUFA intakes were determined from 28 pregnant and 21 lactating French women by using the most recent set of national robust data on food (National Survey INCA2 performed in 2006 and 2007), and compared with that of 742 women of childbearing age. Results Main results showed that mean daily intakes of n-3 PUFA were very low in this French woman population because no pregnant and lactating women met recommended dietary intakes (RDIs). Moreover, some of them ingested quantities 4 times (ALA) to 10 times (DHA) lower than RDIs. Very similar dietary intakes were observed in women of childbearing age. Conclusion French pregnant and lactating women did not change their dietary habits to favor ALA and n-3 long-chain PUFA consumption via rich-ALA vegetable oils and fish and oily fish consumption, and have low n-3 PUFA dietary consumption typical of French women of childbearing age. Such PUFA intakes could have adverse impact on long-chain n-3 PUFA incorporation in brain membranes of fetus and infants, but also on cognitive and visual development of infants during the first years of life.

Recommendations for infant formulas (IF) had been established on the basis of human breast milk composition, still considered as “the gold standard”. Historically, till the 20th century, cow milk-based formulas have been used to feed infants when breast feeding was not possible. Later, infant formulas based on cow’s milk proteins but only vegetable oils blends as lipid source became the usual rule in most countries. However, considering“the gold standard”, a lot of changes occurred since the sixties that considerably modified lipid composition of human breast milk which is correlated to the diet of the mothers, who increased their consumption of n-6PUFA to replace saturated fat considered as proatherogenic. This introduced an imbalance in the ratio of linoleic/alpha-linolenic acids (18:2n-6/18:3n-3), limiting the bioconversion to long-chain-n-3 docosahexaenoic acid (DHA, 22:6n-3). Compared to pure vegetable blends and following the usual recommendations for IF, linoleic (LA 15% of total fatty acids), alpha-linolenic acids (ALA 1.5%) and LA/ALA ratio (10), the use of dairy fat blend was beneficial in terms of brain DHA accretion in young rats and a further increase of brain DHA was obtained by using pure dairy fat (LA 2%, ALA 0.8%, LA/ALA 2.3). Cow’s milk presents naturally some similarities (lipid quality, cholesterol, globule structure…) with human breast milk and cannot be compared to pure vegetable blends. Utilization of dairy fat in infant formula should be reconsidered, as well as the absolute amount of polyunsaturated LA and ALA: at least a reduction of LA for IF as well as for lactating women to improve breast milk quality.

Polyunsaturated fatty acid (PUFA) composition data of the breast milk are rare but essential for assessing the adequate intake of fatty acids in the newborn and possibly directing the mother to a suitable diet or even supplementation with essential fatty acids. The raw data for lactating women from the national study on individual food consumption 2006–2007 (INCA 2) were combined with the French food composition table (Ciqual 2013) to assess their fatty acid intakes. Although this is a limited number of subjects, these data are still interesting to analyze and compare with current Anses recommendations. According to these results, omega-3 PUFA consumption is not sufficient for the purposes of the Recommended Dietary Intakes (RDI). In addition, it has been shown that the fatty acid composition of breast milk is a proven marker of dietary lipid consumption and a good reflection of the consumption’s level of omega-6 and omega-3 PUFAs. Epidemiological data on quantity and quality of lipids consumed in France are rare. In the context of different observational and interventional studies conducted on breast milk, ITERG has been able to estimate the evolution of French food habits for nearly 17 years. A synthesis work has taken over all the data acquired during 3 clinical studies carried out between 1997 and 2014. This synthesis showed a positive evolution of the proportions in omega-3 PUFA in 17 years (1997–2014). However, the proportions of alpha-linolenic acid (ALA) and docosahexaenoic acid (DHA) in breast milk remain below nutritional recommendations for the newborn.; Les données de consommation en acides gras polyinsaturés (AGPI) de la femme allaitante sont rares bien qu’essentielles pour évaluer le niveau d’apport en acides gras du nourrisson et éventuellement orienter la mère vers une alimentation adaptée voire vers une supplémentation en acides gras essentiels. Les données INCA 2 concernant les femmes allaitantes ont été combinées aux données de composition nutritionnelle des aliments de la base de données Ciqual 2013 pour évaluer leurs apports en acides gras. Bien qu’il s’agisse d’un échantillon limité d’individus enquêtés il y a 12 ans, ces données restent malgré tout intéressantes à analyser et à comparer aux recommandations actuelles de l’Anses. Elles montrent que la consommation en AGPI n-3 n’est pas suffisante au regard des recommandations. Par ailleurs, il a été démontré que la composition en acides gras du lait maternel est un marqueur reconnu de la consommation des lipides alimentaires et un bon reflet du niveau de consommation des AGPI n-6 et n-3. Or, les données épidémiologiques relatives à la quantité et à la qualité des lipides consommés en France sont rares. Dans le cadre de différentes études cliniques conduites sur le lait maternel, l’ITERG a pu ainsi estimer l’évolution des habitudes alimentaires des Français depuis près de 17 ans. Un travail de synthèse a repris l’ensemble des données acquises au cours de 4 études cliniques menées entre 1997 et 2014. Cette synthèse a mis en évidence une évolution positive des proportions en AGPI n-3 en 17 ans (1997–2014). Toutefois, les proportions d’acide alpha-linolénique (ALA) et d’acide docosahexaénoïque (DHA) dans le lait maternel restent en deçà des recommandations nutritionnelles pour le nouveau-né.

Objectives: The aim of this study was to explore polyunsaturated fatty acid (PUFA) intakes in the French elderly population (65 to 79 years old). Design: The study used data on French food consumption issued from 348 elderly of the cross-sectional national French INCA 2 dietary survey performed in 2006 and 2007, combined with the nutritional content of food consumed updated in 2013 by the French Information Center on Food Quality. Results: It was observed for the French elderly population an adequate total fat daily intake and a linoleic acid (LA) daily intake close or superior to the recommended dietary intake (RDI) by the French authorities (from 4.1 to 4.4% of the total energy intake excluding alcohol (EIEA) vs 4% EIEA). By contrast, the French elderly have, regardless of age and gender, a low mean dietary alpha-linolenic acid (ALA) intake equal half of the RDI (0.5% EIEA vs 1% EIEA), and a mean dietary docosahexaenoic acid (DHA) intake close to two-thirds of the RDI (i.e. from 154 to 167 mg/d vs 250 mg/d). These translated into a LA/ALA ratio between 9.5 and 9.9, twice as high as the recommended threshold inferior to 5, and a mean dietary eicosapentaenoic acid (EPA) plus DHA intake (from 267 to 293 mg/d) slightly more than half of the RDI (500 mg/d). Conclusion: This study supports the need to promote higher intakes of n-3 PUFAs, as well as the setting of specific intake recommendations for these fatty acids for the French elderly population.

International audience; DHA, an omega-3 fatty acid, is an important constituent of brain membranes and has a key role in brain development and function. This review aims to highlight recent research on DHA's role during age-related cognitive decline and Alzheimer's disease. Animal and in vitro studies have provided some interesting mechanistic leads, especially on brain glucose metabolism, that may be involved in neuroprotection by DHA. However, results from human studies are more mitigated, perhaps due to changing DHA metabolism during aging. Recent innovative tools such as C-13-DHA for metabolic studies and C-11-DHA for PET provide interesting opportunities to study factors that affect DHA homeostasis during aging and to better understand whether and how to use DHA to delay or treat Alzheimer's disease.

Epidemiological observations report an increase in fat consumption associated with low intake of n-3 relative to n-6 polyunsaturated fatty acids (PUFAs) in women of childbearing age. However, the impact of these maternal feeding habits on cognitive function in the offspring is unknown. This study aims to investigate the impact of early exposure to a high-fat diet (HFD) with an unbalanced n-6/n-3 PUFAs ratio on hippocampal function in adult rats. Furthermore, we explored the effects of perinatal HFD combined with exposure to HFD after weaning. Dams were fed a control diet (C, 12% of energy from lipids, n-6/n-3 PUFAs ratio: 5) or HFD (HF, 39% of energy from lipids, n-6/n-3 PUFAs ratio: 39) throughout gestation and lactation. At weaning, offspring were placed either on control (C-C, HF-C) or high-fat (HF-HF) diets. In adulthood, hippocampus-dependent memory was assessed using the water-maze task and potential hippocampal alterations were determined by studying PUFA levels, gene expression, neurogenesis and astrocyte morphology. Perinatal HFD induced long-lasting metabolic alterations and some changes in gene expression in the hippocampus, but had no effect on memory. In contrast, spatial memory was impaired in animals exposed to HFD during the perinatal period and maintained on this diet. HF-HF rats also exhibited low n-3 and high n-6 PUFA levels, decreased neurogenesis and downregulated expression of several plasticity-related genes in the hippocampus. To determine the contribution of the perinatal diet to the memory deficits reported in HF-HF animals, an additional experiment was conducted in which rats were only exposed to HFD starting at weaning (C-HF). Interestingly, memory performance in this group was similar to controls. Overall, our results suggest that perinatal exposure to HFD with an unbalanced n-6/n-3 ratio sensitizes the offspring to the adverse effects of subsequent high-fat intake on hippocampal function.

Specific mechanisms for maintaining docosahexaenoic acid (DHA) concentration in brain cells but also transporting DHA from the blood across the blood-brain barrier (BBB) are not agreed upon. Our main objective was therefore to evaluate the level of gene expression of fatty acid transport and fatty acid binding proteins in the cerebral cortex and at the BBB level during the perinatal period of active brain DHA accretion, at weaning, and until the adult age. We measured by real time RT-PCR the mRNA expression of different isoforms of fatty acid transport proteins (FATPs), long-chain acyl-CoA synthetases (ACSLs), fatty acid binding proteins (FABPs) and the fatty acid transporter (FAT)/CD36 in cerebral cortex and isolated microvessels at embryonic day 18 (E18) and postnatal days 14, 21 and 60 (P14, P21 and P60, respectively) in rats receiving different n-3 PUPA dietary supplies (control, totally deficient or DHA-supplemented). In control rats, all the genes were expressed at the BBB level (P14 to P60), the mRNA levels of FABP5 and ACSL3 having the highest values. Age-dependent differences included a systematic decrease in the mRNA expressions between P14-P21 and P60 (2 to 3-fold), with FABP7 mRNA abundance being the most affected (10-fold). In the cerebral cortex, mRNA levels varied differently since FATP4, ACSL3 and ACSL6 and the three FABPs genes were highly expressed. There were no significant differences in the expression of the 10 genes studied in n-3 deficient or DHA-supplemented rats despite significant differences in their brain DHA content, suggesting that brain DHA uptake from the blood does not necessarily require specific transporters within cerebral endothelial cells and could, under these experimental conditions, be a simple passive diffusion process.

Optimal levels of unsaturated fatty acids have positive impacts on the use of prolonged bouts of hypothermia in mammalian hibernators, which generally have to face low winter ambient temperatures. Unsaturated fatty acids can maintain the fluidity of fat and membrane phospholipids at low body temperatures. However, less attention has been paid to their role in the regulation of shallow hypothermia, and in tropical species, which may be challenged more by seasonal energetic and/or water shortages than by low temperatures. The present study assessed the relationship between the fatty acids content of white adipose and liver tissues and the expression of shallow hypothermia in a tropical heterothermic primate, the gray mouse lemur (Microcebus murinus). The adipose tissue is the main tissue for fat storage and the liver is involved in lipid metabolism, so both tissues were expected to influence hypothermia dependence on fatty acids. As mouse lemurs largely avoid deep hypothermia (i.e. torpor) use under standard captive conditions, the expression of hypothermia was triggered by food-restricting experimental animals. Hypothermia depth increased with time, with a stronger increase for individuals that exhibited higher contents of unsaturated fatty acids suggesting that they were more flexible in their use of hypothermia. However these same animals delayed the use of long hypothermia bouts relative to individuals with a higher level of saturated fatty acids. This study evidences for the first time that body fatty acids unsaturation levels influence the regulation of body temperature not only in cold-exposed hibernators but also in tropical, facultative heterotherms.