Very low inadequate dietary intakes of essential n-3 polyunsaturated fatty acids (PUFA) in pregnant and lactating French women: The INCA2 survey.

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.

Inhibitory effects of omega-3 fatty acids on injury-induced epidermal growth factor receptor transactivation contribute to delayed wound healing.

Epidermal growth factor receptor (EGFR)-mediated signaling is required for optimal intestinal wound healing. Since n-3 polyunsaturated fatty acids (PUFA), specifically docosahexaenoic acid (DHA), alter EGFR signaling and suppress downstream activation of key signaling pathways, we hypothesized that DHA would be detrimental to the process of intestinal wound healing. Using a mouse immortalized colonocyte model, DHA uniquely reduced EGFR ligand-induced receptor activation, whereas DHA and its metabolic precursor eicosapentaenoic acid (EPA) reduced wound-induced EGFR transactivation compared with control (no fatty acid or linoleic acid). Under wounding conditions, the suppression of EGFR activation was associated with a reduction in downstream activation of cytoskeletal remodeling proteins (PLCγ1, Rac1, and Cdc42). Subsequently, DHA and EPA reduced cell migration in response to wounding. Mice were fed a corn oil-, DHA-, or EPA-enriched diet prior to intestinal wounding (2.5% dextran sodium sulfate for 5 days followed by termination after 0, 3, or 6 days of recovery). Mortality was increased in EPA-fed mice and colonic histological injury scores were increased in EPA- and DHA-fed mice compared with corn oil-fed (control) mice. Although kinetics of colonic EGFR activation and downstream signaling (PLCγ1, Rac1, and Cdc42) were delayed by both n-3 PUFA, colonic repair was increased in EPA- relative to DHA-fed mice. These results indicate that, during the early response to intestinal wounding, DHA and EPA uniquely delay the activation of key wound-healing processes in the colon. This effect is mediated, at least in part, via suppression of EGFR-mediated signaling and downstream cytoskeletal remodeling.

Healing fats of the skin: the structural and immunologic roles of the omega-6 and omega-3 fatty acids.

Linoleic acid (18:2omega6) and alpha-linolenic acid (18:3omega3) represent the parent fats of the two main classes of polyunsaturated fatty acids: the omega-6 (n-6) and the omega-3 (n-3) fatty acids, respectively. Linoleic acid and alpha-linolenic acid both give rise to other long-chain fatty acid derivatives, including gamma-linolenic acid and arachidonic acid (omega-6 fatty acids) and docosahexaenoic acid and eicosapentaenoic acid (omega-3 fatty acids). These fatty acids are showing promise as safe adjunctive treatments for many skin disorders, including atopic dermatitis, psoriasis, acne vulgaris, systemic lupus erythematosus, nonmelanoma skin cancer, and melanoma. Their roles are diverse and include maintenance of the stratum corneum permeability barrier, maturation and differentiation of the stratum corneum, formation and secretion of lamellar bodies, inhibition of proinflammatory eicosanoids, elevation of the sunburn threshold, inhibition of proinflammatory cytokines (tumor necrosis factor-alpha, interferon-gamma, and interleukin-12), inhibition of lipoxygenase, promotion of wound healing, and promotion of apoptosis in malignant cells, including melanoma. They fulfill these functions independently and through the modulation of peroxisome proliferator-activated receptors and Toll-like receptors.

Effects of alpha-linolenic acid on colonic secretion in rats with experimental colitis.

BACKGROUND: Few studies have specifically examined the effects of n-3 polyunsaturated fatty acids (PUFAs) on intestinal water and ion secretion in ulcerative colitis (UC). The aim of this study was to examine the contribution of prostaglandins (PGs) and leukotrienes (LTs) to mucosal secretion in intestines with UC and to evaluate the effect of dietary n-3 PUFAs on diarrhea in UC. METHODS: We measured the short-circuit current (Isc), using the Ussing chamber method, and fatty acid composition in the colonic mucosa of rats with dextran sulfate sodium (DSS)-induced experimental colitis. The DSS-treated rats were fed either a perilla oil-enriched diet (perilla group) or a soybean oil-enriched diet (soybean group); a control group did not undergo DSS administration. RESULTS: The bradykinin-stimulated DeltaIsc in the soybean and perilla groups was significantly higher than that in the control group. The mucosal level of arachidonic acid in the perilla group was significantly lower than that in the soybean group. The mucosal levels of alpha-linolenic acid and EPA in the perilla group were significantly higher than those in the soybean group. The bradykinin-stimulated DeltaIsc was significantly suppressed after pretreatment with indomethacin in both the soybean and perilla groups, and was also significantly reduced in both groups after pretreatment with AA861. The suppression of bradykinin-stimulated DeltaIsc by the addition of AA861 was significantly higher in the perilla group than in the soybean group. CONCLUSIONS: Our results suggest that supplementation with alpha-linolenic acid, in combination with a lipoxygenase inhibitor, could suppress the increase in Cl- secretion in patients with UC.

Effects of menhaden oil and flaxseed in broiler diets on sensory quality and lipid composition of poultry meat.

1. Three hundred and thirty 1-d-old male broiler chicks from a commercial strain were allocated to 11 dietary treatments comprising combinations of flaxseed at 100 g/kg and menhaden oil (MO) at 7.5 or 15 g/kg. Birds were given the experimental diets 7 or 14 d prior to slaughter. Carcase omega-3 fatty acid profiles and sensory evaluations of different cooked meat portions were carried out. 2. Linolenic acid was preferentially deposited in dark meat and long chain omega-3 fatty acids in white meat. Breast meat sensory quality was not affected in birds given 100 g/kg flaxseed for 14 d (treatment 3), 7.5 g/kg MO for 14 d (treatment 5) or 100 g/kg flaxseed +0.75 g/kg MO for 7 d (treatment 6). In contrast, thigh meat sensory quality decreased in treatments 5 and 6. 3. Feeding flaxseed and MO to birds for just 7 d prior to slaughter resulted in significant omega-3 meat enrichment depending on their dietary concentrations. The linolenic acid and long chain omega-3 fatty acids showed preferential deposition in dark and white meat, respectively, which may affect the sensory quality of various portions differently.

Importance of n-3 fatty acids in health and disease.

In the past 2 decades, views about dietary n-3 fatty acids have moved from speculation about their functions to solid evidence that they are not only essential nutrients but also may favorably modulate many diseases. Docosahexaenoic acid (22:6n-3), which is a vital component of the phospholipids of cellular membranes, especially in the brain and retina, is necessary for their proper functioning. n-3 Fatty acids favorably affect atherosclerosis, coronary heart disease, inflammatory disease, and perhaps even behavioral disorders. The 38 articles in this supplement document the importance of n-3 fatty acids in both health and disease.

Placental delivery of arachidonic and docosahexaenoic acids: implications for the lipid nutrition of preterm infants.

Arachidonic (AA) and docosahexaenoic (DHA) acids are major components of cell membranes and are of special importance to the brain and blood vessels. In utero, the placenta selectively and substantially extracts AA and DHA from the mother and enriches the fetal circulation. Studies indicate that there is little placental conversion of the parent essential fatty acids to AA and DHA. Similarly, analyses of desaturation and reductase activity have shown the placenta to be less functional than the maternal or fetal livers. There appears to be a correlation with placental size and plasma AA and DHA proportions in cord blood; therefore, placental development may be an important variable in determining nutrient transfer to the fetus and, hence, fetal growth itself. In preterm infants, both parenteral and enteral feeding methods are modeled on term breast milk. Consequently, there is a rapid decline of the plasma proportions of AA and DHA to one quarter or one third of the intrauterine amounts that would have been delivered by the placenta. Simultaneously, the proportion of linoleic acid, the precursor for AA, rises in the plasma phosphoglycerides 3-fold. An inadequate supply of AA and DHA during the period of high demand from rapid vascular and brain growth could lead to fragility, leakage, and membrane breakdown. Such breakdown would predictably be followed by peroxidation of free AA, vasoconstriction, inflammation, and ischemia with its biological sequelae. In the brain, cell death would be an extreme consequence.

[Pathology of placenta of rats induced by fatty acid deficiency]. / Patología de la placenta de rata inducida por la deficiencia de ácidos grasos.

Lipids are important cell components, both from the structural and the functional point of view. Besides, they intervene in transporting functions, cell recognition and immunity. Essential Fatty Acids (EFA) are important for the functional and structural maintenance of animal organisms. In our laboratory, it was demonstrated that one group of pregnant rats fed on an EFA deficient diet, and other group of rats fed on the same diet but with 5% of corn oil (rich in linoleic acid) showed alterations on the development of the metrial gland. In the present work, 57 female rats of a Wistar strain were fed since weaning with one of the following diets: EFAD: deficient in essential fatty acids, COD: EFAD + 5% corn oil (linoleic acid sufficient but alpha-linoleic acid deficient); SAD: EFAD + 5% soy oil (both EFA sufficient) and CD: commercial diet. After 3 months the animals were sacrificed on the 13 th. day of gestation. Uteru's horns were dissected and the implantation sities were fixed on formol and embebbed in parafin. The observations were carried out with H/E coloured cross-sections and the corialantoidea placenta, the cities of implantations and the sitios of reabsortions were studied. The metrial gland of DAGE and DAM rats presented structural modifications compared to DC rats. The most relevant findings were: indifferentiation of the granulated metrial gland cells and an increase in the amount of connective tissue. In DAS rats, on the contrary, the aspect of the metrial gland was similar to the observed in the DC group. In the DAGE and the DAM groups Labyrinthium was enlarged with vascular septum group. Mean while DAS was similar to group DC (thin and vascular). Differences in the cities of implantations and reabsortions were not detected. The present results suggest that alpha-linolenico acid is essential for the rat placenta to reach normal development.

Role of plant-derived omega-3 fatty acids in human nutrition.

An international workshop on the role of plant-derived omega-3 fatty acids in human nutrition took place in Milan on February 9, 2000. The meeting was sponsored by the Nutrition Foundation of Italy and was organized by its Scientific Director, Dr. Andrea Poli. It was attended by experts in polyunsaturated fatty acids and human lipid nutrition. This is the first meeting devoted to the health aspects of alpha-linolenic acid, the omega-3 fatty acid contained in plant-derived edible products, as distinct from the more widely studied long-chain omega-3 products typically present in fish and fish-derived products. This report, which is based on updated scientific evidence presented and discussed at the workshop, was prepared by the international expert panel.

Patología de la placenta de rata inducida por la deficiencia de ácidos grasos / Pathology of placenta of rats induced by fatty acid deficiency

Los lípidos son componentes importantes de las células, tanto desde el punto de vista estructural como funcional. Además de intervenir en funciones de transporte, reconocimiento celular e inmunidad, los Acidos Grasos Esenciales (AGE) , son importantes para el mantenimiento funcional y estructural de los organismos animales. En nuestro laboratorio se demostró que ratas preñadas alimentadas con dietas deficientes en ácidos grasos esenciales (DAGE ) y otras con las mismas dietas pero suplementadas con 5 por ciento de aceite de maíz, ( rico en ácido linoleico ) mostraron alteraciones en el desarrollo placentario. En el presente trabajo, 57 ratas hembras de una cepa Wistar fueron alimentadas desde el destete con una de las siguientes dietas: 1: DAGE; 2 :DAM (dieta DAGE más aceite de maíz , alta proporción de ácido linoléico); 3: DAS (dieta DAGE más aceite de soja, alta proporción de ácidos linoleico y a-linolénico) y 4 :DC (dieta comercial). Después de los 3 meses de edad los animales fueron preñados y se sacrificaron al 13 día de la gestación. Los cuernos uterinos fueron disecados y los sitios de implantación se fijaron en formol y se incluyeron en parafina. Las observaciones se realizaron sobre cortes coloreados con H/E , y se estudió la placenta corioalantoidea , el número de implantaciones y el de reabsorciones . La glándula metrial de ratas DAGE y DAM presentaron modificaciones estructurales en relación a las DC. Los hallazgos más notables fueron : Indiferenciación de las células granulares metriales y aumento de la cantidad de tejido conectivo. En las ratas DAS ,en cambio,el aspecto de la glándula metrial era similar a lo observado en el grupo DC. En los grupos DAGE y DAM el laberinto estaba ensanchado, con septos vasculares pero en el grupo DAS eran similares al DC, delgados y vasculares. No se detectaron diferencias en el número de implantaciones y reabsorciones. Los presentes resultados sugieren que el ácido a-linolénico dietético es esencial para que la placenta de rata alcance su desarrollo normal. (Au)

Effects of dietary n-3 fatty acid deficiency and repletion in the guinea pig retina.

PURPOSE: To investigate the nature and reversibility of biochemical and functional changes in the retina encountered over a single generation of dietary n-3 polyunsaturated fatty acid deficiency in guinea pigs. METHODS: Dunkin-Hartley guinea pigs were fed for 16 weeks after weaning with diets supplemented with safflower seed oil (n-3 deficient) or canola oil (n-3 sufficient, control). A number of deficient animals were repleted at 6 weeks with canola oil for 5 or 10 weeks, or at 11 weeks for 5 weeks. Electroretinograms (0.8 and 4.3 log scot td x sec) were collected at 6, 11, and 16 weeks after weaning. Conventional waveforms (a- and b-waves), oscillatory potentials, and receptoral and postreceptoral subcomponents (PIII and PII, respectively) were evaluated. Cone pathway function was assessed with 30-Hz flicker at the brighter intensity. Retinal phospholipid fatty acids were measured by capillary gas-liquid chromatography. RESULTS: Electroretinographic amplitudes showed statistically significant losses in b- and a-waves after 6 and 16 weeks of dietary n-3 deficiency, respectively. The response amplitude to 30-Hz flicker was reduced 42% after 16 weeks. Retinal docosahexaenoic acid (DHA) levels of animals maintained on the safflower oil diet for 16 weeks were 42% of levels in age-matched control subjects. There were significant losses in maximum response amplitudes (R(mPIII) and R(mPII)), although the major effect was a reduction in sensitivity of the receptoral response. Complete functional recovery was observed only in animals repleted for 10 weeks. CONCLUSIONS: Functional deficits in PIII and PII of the electroretinogram were apparent in first-generation guinea pigs fed an n-3 deficient diet. These losses showed a correlation with age and retinal DHA level, although varying degrees of dependence on the DHA level were found. All functional deficits were reversed after 10 weeks of dietary n-3 repletion. The results suggest that DHA may serve several functional and structural roles in the retina and further emphasize the requirement for DHA in the normal development of vision.