Perinatal biochemistry and physiology of long-chain polyunsaturated fatty acids

Long chain fatty acids and dietary fats in fetal nutrition

Long chain polyunsaturated fatty acids are essential nutrients for a healthy diet. The different kinds consumed by the mother during gestation and lactation may influence pregnancy, fetal and also neonatal outcome. The amount of fatty acids transferred from mother to fetus depends not only on maternal metabolism but also on placental function, i.e. by the uptake, metabolism and then transfer of fatty acids to the fetus. The third trimester of gestation is characterized by an increase of long chain polyunsaturated fatty acids in the fetal circulation, in particular docosahexaenoic acid, especially to support brain growth and visual development. These mechanisms may be altered in pathological conditions, such as intrauterine growth restriction and diabetes, when maternal and fetal plasma levels of long chain polyunsaturated fatty acids undergo significant changes. The aim of this review is to describe the maternal and placental factors involved in determining fetal fatty acid availability and metabolism, focusing on the specific role of long chain polyunsaturated fatty acids in normal and pathological pregnancies.

Fatty acid patterns early after premature birth, simultaneously analysed in mothers' food, breast milk and serum phospholipids of mothers and infants

Background

The supply of long-chain polyunsaturated fatty acids via the placenta is interrupted in premature infants, making them exclusively dependent on breast milk, which varies in fatty acid (FA) concentrations depending on the mother's diet.

Objective

To in a longitudinal study explore the relation between FA status in mothers and infants from an unselected cohort of prematures, not requiring intensive care.

Design

Breast milk and mothers' and infants' plasma phospholipid FA concentrations from birth to 44 weeks of gestational age were analysed and compared with mothers' food intake, assessed using a 3-day diary. Fatty acids were analysed by capillary gas-liquid chromatography.

Results

The energy intake was low in 75% of mothers, and 90% had low intake of essential FAs (EFAs). Dietary linoleic acid (LA, 18:2w6), but not w3 FAs, correlated to concentrations in breast milk. Infants' plasma and breast milk correlated for arachidonic (AA, 20:4w6), eicosapentaenoic (EPA, 20:5w3) and docosahexaenoic (DHA, 22:6w3) acids. A high concentration of mead acid (20:3w9) in the infants at birth correlated negatively to the concentrations of LA, AA and w3 FAs. Infants of mothers who stopped breastfeeding during the study period showed decreased DHA concentrations and increased w6/w3 ratios, with the opposite FA pattern seen in the mothers' plasma.

Conclusion

Although dietary w3 FAs were insufficient in an unselected cohort of mothers of premature infants, breastfeeding resulted in increased levels of DHA in the premature infants at the expense of the mothers, suggesting a general need to increase dietary w3 FAs during pregnancy and lactation.

n-3 Fatty acid intake from marine food products among Quebecers: comparison to worldwide recommendations

Objective

To quantify marine food product consumption and EPA + DHA intake among Quebecers, and to compare the results with the most recent recommendations.

Design

Data were obtained from a representative cross-sectional telephone survey (June 2006). Intakes of marine food product species and EPA + DHA were estimated from a validated FFQ on the consumption of marine food products during the previous month. Prevalence of fish oil consumption in the last 6 months was also assessed.

Setting

Province of Quebec (Canada).

Subjects

A representative sample (n 1001) of adults in the province of Quebec. Of these, eight were excluded from the present analysis (n 993).

Results

Mean and median EPA + DHA intakes for all participants were estimated to be 291 mg/d (sem 11) and 207 mg/d, respectively. 85·0 % (95 % CI 82·7, 87·3) of Quebecers had an EPA + DHA intake lower than 500 mg/d, which is the amount internationally recommended for the prevention of CVD. Mean and median DHA intakes among women of childbearing age (n 128, 18–34 years) were estimated to be 169 mg/d (sem 17) and 126 mg/d, respectively. Of these women, 27·7 % had a daily intake >200 mg DHA and 15·9 % had an intake >300 mg DHA. We noted that 13 % of Quebecers take ≥1 capsule of fish oil/d.

Conclusions

Consumption of marine food products and EPA + DHA among Quebecers clearly appears to be lower than international recommendations. Since EPA + DHA confer health benefits and may reduce health costs, strategies to increase their consumption should be implemented to improve public health in Quebec.

Early determinants of development: a lipid perspective

This article results from an International Life Sciences Institute workshop on early nutritional determinants of health and development. The presentation on lipids focused mainly on the longer-chain products of the essential fatty acids, particularly docosahexaenoic acid (22:6n-3), and cognitive development as among the most studied lipids and outcomes, respectively, in early human nutrition. Because there have been several recent reviews on this topic, the present review takes a broader perspective with respect to both early development and lipids: an expanded research agenda is plausible on the basis of observations from some human studies and from animal studies. Other lipids known to be provided in variable amounts to infants through human milk are cholesterol and gangliosides. Short sections address the current state of knowledge and some questions that could be pursued.

Driving research in infant and children's nutrition: a perspective on industry

As part of the workshop entitled "Early Risk Determinants and Later Health Outcomes: Implications for Research Prioritization and the Food Supply" (8-9 July 2008, Washington, DC), which was cosponsored by the International Life Sciences Institute of North America and the International Life Sciences Institute Research Foundation, representatives of the food industry discussed the practical application of nutrition science. Nutrition plays a key role in guiding health outcomes throughout the life cycle. In particular, the prenatal, postnatal, and early childhood periods are extremely sensitive to the presence of appropriate nutrition. A growing body of evidence shows that early nutrition may program the unborn and the infant's key physiologic systems, including the endocrine, cardiovascular, and central nervous systems, to influence later life outcomes. While scientists in academia continue to explore the multifactorial nature of early risk determinants and later life outcomes at a mechanistic and basic science level, it is important to understand the potential of the infant and child food industries to address questions such as what factors have been noted to drive research in these sectors of the food industry. How can scientists in these industries work alongside the scientists in academia and in government to set priorities, make decisions around these health issues, and translate academic insights into innovative nutritional solutions for the benefit of public health? Given the commitment of the infant and child food industries to deliver scientifically supported early life nutrition, it is easy to understand why this industry would work in partnership with both the scientists in academia and the government to identify a means of addressing the fundamental questions of this workshop.

Omega-3 deficiency associated with perinatal depression: case control study

Women are depleted of omega-3 polyunsaturated fatty acids (n-3 PUFAs) during the perinatal period due to fetal diversion. An association has been shown between lowered n-3 PUFAs and depression in general. We therefore hypothesise that women with lower n-3 PUFA levels are at greater risk of depression during pregnancy. Sixteen depressed and 22 non-depressed women were recruited during the third trimester and fasting bloods were taken for plasma fatty acid analysis. High docosahexaenoic acid (DHA), high total n-3 and a low n-6:n-3 ratio were associated with significantly lower odds of depression. After adjustment for parity, age and education level, those with high DHA still had significantly lower odds of being depressed. Those with high total n-3 and a low n-6:n-3 ratio were also at significantly reduced risk of depression, although the magnitude of the difference was reduced. Study results quantified women with lower omega-3 PUFA levels as being six times more likely to be depressed antenatally, compared to women who had higher omega-3 PUFA levels. The prophylactic benefits of supplementation either prenatally or during pregnancy require close study to assess whether omega-3 PUFAs play a role in the prevention of perinatal depression.

A systemic review of the roles of n-3 fatty acids in health and disease

Attention to the role of n-3 long-chain fatty acids in human health and disease has been continuously increased during recent decades. Many clinical and epidemiologic studies have shown positive roles for n-3 fatty acids in infant development; cancer; cardiovascular diseases; and more recently, in various mental illnesses, including depression, attention-deficit hyperactivity disorder, and dementia. These fatty acids are known to have pleiotropic effects, including effects against inflammation, platelet aggregation, hypertension, and hyperlipidemia. These beneficial effects may be mediated through several distinct mechanisms, including alterations in cell membrane composition and function, gene expression, or eicosanoid production. A number of authorities have recently recommended increases in intakes of n-3 fatty acids by the general population. To comply with this recommendation a variety of food products, most notably eggs, yogurt, milk, and spreads have been enriched with these fatty acids. Ongoing research will further determine the tissue distribution, biological effects, cost-effectiveness, and consumer acceptability of such enriched products. Furthermore, additional controlled clinical trials are needed to document whether long-term consumption or supplementation with eicosapentaenoic acid/docosahexaenoic acid or the plant-derived counterpart (alpha-linolenic acid) results in better quality of life.

Human milk arachidonic acid and docosahexaenoic acid contents increase following supplementation during pregnancy and lactation

INTRODUCTION

Docosahexaenoic acid (DHA) and arachidonic acid (AA) are important for neurodevelopment. Maternal diet influences milk DHA, whereas milk AA seems rather constant. We investigated milk AA, DHA and DHA/AA after supplementation of AA plus DHA, or DHA alone during pregnancy and lactation.

SUBJECTS AND METHODS

Women were supplemented with AA+DHA (220mg each/day), DHA (220mg/day) or placebo during pregnancy and lactation. Milk samples were collected at 2 (n=86) and 12 weeks (n=69) postpartum.

RESULTS

Supplementation of AA+DHA elevated milk AA (week 2, 14%; week 12, 23%) and DHA (43% and 52%) as compared to placebo. DHA tended to decrease milk AA and vice versa. Milk AA, DHA and DHA/AA decreased from 2 to 12 weeks postpartum.

CONCLUSIONS

Milk AA and in particular DHA are sensitive to maternal supplementation. It seems that maternal AA and notably DHA status decline with advancing lactation.

Composition of the milk of the quokka (Setonix brachyurus)

We investigated the composition of the milk of the quokka between 70 and 300 days post partum. From 70 to 180 days, the mean concentration of protein in the milk was 63.5 ± 6.50 g L−1. The protein levels then began to increase, peaking at 120 g L−1 towards the end of lactation. The mean lipid and total solids content were 45.0 ± 6.50 and 175.0 ± 11.77 g L−1 from 70–180 days, increasing to 150 and 250 g L−1 after permanent pouch exit. In contrast, the total carbohydrate concentration of the milk decreased from 80 to 20 g L−1 at 150 days. The concentration of lactose started to decrease at 180 days from 30 to 10 g L−1, and galactose and glucose began to rise from 1 to 9 g L−1 and 0.5 to 4.0 g L−1, respectively. The milk lipid consisted mainly of long- and medium-chain fatty acids, with no short-chain fatty acids detected. The major fatty acids present were palmitic and oleic acids, followed by linoleic, trans-vaccenic and stearic acids. The percentage composition of oleic and stearic acids varied significantly during lactation. The composition of the milk of the quokka changed during lactation, coincident with the young reaching critical milestones in its development. This finding supports the hypothesis that the composition of the milk changes to meet the nutritional needs of the developing young.

Maternal DHA levels and toddler free-play attention

We investigated the relationship between maternal docosahexaenoic acid (DHA) levels at birth and toddler free-play attention in the second year. Toddler free-play attention was assessed at 12 and 18 months, and maternal erythrocyte (red-blood cell; RBC) phospholipid DHA (percentage of total fatty acids) was measured from mothers at delivery. Overall, higher maternal DHA status at birth was associated with enhanced attentional functioning during the second year. Toddlers whose mothers had high DHA at birth exhibited more total looking and fewer episodes of inattention during free-play than did toddlers whose mothers had low DHA at birth. Analyses also provided further information on changes in attention during toddlerhood. These findings are consistent with evidence suggesting a link between DHA and cognitive development in infancy and early childhood.

Effect of dietary Lorenzo's oil and docosahexaenoic acid treatment for Zellweger syndrome

We investigated the possible therapeutic effect of decreasing plasma levels of very-long-chain fatty acids (C26:0) with a synthetic oil containing trioleate and trielucate (Lorenzo's oil) as well as increasing docosahexaenoic acid (DHA) in red blood cells (RBC) with DHA ethyl ester in four patients with Zellweger syndrome. We investigated serial changes of plasma C26:0 levels and DHA levels in RBC membranes by gas-liquid chromatography/mass spectrometry (GC/MS). After death, the fatty acid composition of each patient's cerebrum and liver was studied. Dietary administration of Lorenzo's oil diminished plasma C26:0 levels. Earlier administration of Lorenzo's oil was more effective and the response did not depend on the duration of administration. DHA was incorporated into RBC membrane lipids when administrated orally, and its level increased for several months. The final DHA level was correlated with the duration of administration and was not related to the timing of initiation of treatment. DHA levels in the brains and livers of treated patients were higher than in untreated patients. Early initiation of Lorenzo's oil and the long-term administration of DHA may be useful for patients with Zellweger syndrome.

Ethnic differences in early pregnancy maternal n-3 and n-6 fatty acid concentrations: an explorative analysis

Ethnicity-related differences in maternal n-3 and n-6 fatty acid status may be relevant to ethnic disparities in birth outcomes observed worldwide. The present study explored differences in early pregnancy n-3 and n-6 fatty acid composition of maternal plasma phospholipids between Dutch and ethnic minority pregnant women in Amsterdam, the Netherlands, with a focus on the major functional fatty acids EPA (20 : 5n-3), DHA (22 : 6n-3), dihomo-gamma-linolenic acid (DGLA; 20 : 3n-6) and arachidonic acid (AA; 20 : 4n-6). Data were derived from the Amsterdam Born Children and their Development (ABCD) cohort (inclusion January 2003 to March 2004). Compared with Dutch women (n 2443), Surinamese (n 286), Antillean (n 63), Turkish (n 167) and Moroccan (n 241) women had generally lower proportions of n-3 fatty acids (expressed as percentage of total fatty acids) but higher proportions of n-6 fatty acids (general linear model; P < 0.001). Ghanaian women (n 54) had higher proportions of EPA and DHA, but generally lower proportions of n-6 fatty acids (P < 0.001). Differences were most pronounced in Turkish and Ghanaian women, who, by means of a simple questionnaire, reported the lowest and highest fish consumption respectively. Adjustment for fish intake, however, hardly attenuated the differences in relative EPA, DHA, DGLA and AA concentrations between the various ethnic groups. Given the limitations of this observational study, further research into the ethnicity-related differences in maternal n-3 and n-6 fatty acid patterns is warranted, particularly to elucidate the explanatory role of fatty acid intake v. metabolic differences.

Effect of dietary levels of corn oil on maternal arachidonic acid synthesis and fatty acid composition in lactating rats

OBJECTIVE

We examined the effect of different amounts of dietary corn oil rich in linoleic acid (LA) on the endogenous synthesis of arachidonic acid (AA), uptake of its precursor LA, and fatty acid composition of tissues involved in the supply of long-chain polyunsaturated fatty acids for milk synthesis.

METHODS

Female Sprague Dawley rats received one of the following diets during pregnancy and lactation: a low-lipid diet (LLD; 2%), an adequate-lipid diet (ALD; 5%), or a high-lipid diet (HLD; 10%). Lipids were provided by corn oil. On day 12 of lactation we measured the endogenous synthesis of AA and quantified the conversion of (13)C-LA to (13)C-AA and the metabolic fate of (13)C-LA from all dietary groups.

RESULTS

The LLD rats demonstrated larger amounts of endogenous synthesis of (13)C-AA and more dietary (13)C-LA transferred to the mammary gland (MG) than HLD rats during lactation. The proportion of medium-chain fatty acids was higher in the MG, milk clot, and liver of LLD than of HLD rats. Daily volume and 24-h yield of lipids and energy were lower in LLD rats than in HLD rats. Measurements of milk composition demonstrated that fat concentration significantly increased as lipid concentration increased in the diet.

CONCLUSION

These results suggest that maternal adaptations used to compensate for diets deficient in long-chain polyunsaturated fatty acids include increased endogenous synthesis of AA and elevated uptake of LA in the MG and increased synthesis of medium-chain polyunsaturated fatty acids. It appears that the MG and liver participate together for AA synthesis for milk when this fatty acid is not provided in the diet.

Maternal di-(2-ethylhexyl)-phthalate exposure influences essential fatty acid homeostasis in rat placenta

Maintaining essential fatty acid (EFA) homeostasis during pregnancy is critical for fetal development. As the organ that controls the maternal-to-fetal supply of nutrients, the placenta plays a significant role in guiding EFA transfer to the fetus. Many EFA homeostasis proteins are regulated by peroxisome proliferator-activated receptors (PPARs). The metabolites of di-(2-ethylhexyl)-phthalate (DEHP), a ubiquitous environmental contaminant, might influence EFA homeostasis via trans-activation of PPARs with subsequent downstream effects on EFA transporters and enzymes. To investigate DEHP's effect on placental/fetal EFA homeostasis, female Sprague-Dawley rats were orally gavaged with either vehicle or DEHP at 750 or 1500 mg/kg/day from gestational day (GD) 0 to GD 19. Changes in the expression of several EFA homeostasis regulating proteins were determined in the junctional (JXN) and labyrinthine (LAB) zones of the placenta, including PPAR isoforms (alpha, beta and gamma), fatty acid translocase (FAT/CD36), fatty acid transport protein 1 (FATP1), plasma membrane fatty acid binding protein (FABPpm), heart cytoplasmic fatty acid binding protein (HFABP), cytochrome P450 (CYP) 4A1, and cyclooxygenase (COX)-1 and -2. Additionally, effects of DEHP maternal exposure on the placental transfer and fetal distribution of representative EFAs, arachidonic acid (AA) and docosahexaenoic acid (DHA), and the placental production of prostaglandins (PGs) were investigated. Expression of PPARalpha, PPARgamma, FAT/CD36, FATP1, HFABP and CYP4A1 was up-regulated in JXN and/or LAB while COX-2 was down-regulated in JXN. PPARbeta, FABPpm, and COX-1 demonstrated variable expression. Reduced directional maternal-to-fetal placental transfer and altered fetal distribution of AA and DHA were observed in concordance with a decreased total placental PG production. These results correlate with previous in vitro data, suggesting that DEHP could influence placental EFA homeostasis with potential downstream effects in the developing fetus.

Dietary omega 3 fatty acids and the developing brain

The omega-3 fatty acids are essential dietary nutrients and one of their important roles is providing the fatty acid with 22 carbons and 6 double bonds known as docosahexaenoic acid (DHA) for nervous tissue growth and function. Inadequate intakes of omega-3 fatty acids decrease DHA and increase omega-6 fatty acids in the brain. Decreased DHA in the developing brain leads to deficits in neurogenesis, neurotransmitter metabolism, and altered learning and visual function in animals. Western diets are low in omega-3 fatty acids, including the 18 carbon omega-3 fatty acid alpha linolenic acid found mainly in plant oils, and DHA, which is found mainly in fish. The DHA status of the newborn and breast-fed infant depends on the maternal intake of DHA and varies widely. Epidemiological studies have linked low maternal DHA to increased risk of poor child neural development. Intervention studies have shown improving maternal DHA nutrition decreases the risk of poor infant and child visual and neural development. Thus, sufficient evidence is available to conclude that maternal fatty acid nutrition is important to DHA transfer to the infant before and after birth, with short and long-term implications for neural function. However, genetic variation in genes encoding fatty acid desaturases also influence essential fatty acid metabolism, and may increase requirements in some individuals. Consideration of omega-3 fatty acid to include brain development, optimizing omega-3 and omega-6 fatty acids in gestation and lactation, and in fatty acid nutrition support for intravenous and formula-fed neonates is important.

Associations of maternal long-chain polyunsaturated fatty acids, methyl mercury, and infant development in the Seychelles Child Development Nutrition Study

Fish consumption during gestation can provide the fetus with long-chain polyunsaturated fatty acids (LCPUFA) and other nutrients essential for growth and development of the brain. However, fish consumption also exposes the fetus to the neurotoxicant, methyl mercury (MeHg). We studied the association between these fetal exposures and early child development in the Seychelles Child Development Nutrition Study (SCDNS). Specifically, we examined a priori models of Omega-3 and Omega-6 LCPUFA measures in maternal serum to test the hypothesis that these LCPUFA families before or after adjusting for prenatal MeHg exposure would reveal associations with child development assessed by the BSID-II at ages 9 and 30 months. There were 229 children with complete outcome and covariate data available for analysis. At 9 months, the PDI was positively associated with total Omega-3 LCPUFA and negatively associated with the ratio of Omega-6/Omega-3 LCPUFA. These associations were stronger in models adjusted for prenatal MeHg exposure. Secondary models suggested that the MeHg effect at 9 months varied by the ratio of Omega-6/Omega-3 LCPUFA. There were no significant associations between LCPUFA measures and the PDI at 30 months. There were significant adverse associations, however, between prenatal MeHg and the 30-month PDI when the LCPUFA measures were included in the regression analysis. The BSID-II mental developmental index (MDI) was not associated with any exposure variable. These data support the potential importance to child development of prenatal availability of Omega-3 LCPUFA present in fish and of LCPUFA in the overall diet. Furthermore, they indicate that the beneficial effects of LCPUFA can obscure the determination of adverse effects of prenatal MeHg exposure in longitudinal observational studies.

[The treatment of Attention-Deficit/Hyperactivity Disorders with polyunsaturated fatty acids - an effective treatment alternative?]

OBJECTIVES

Both omega-3 and omega-6 long-chain polyunsaturated fatty acids (PUFA) have a substantial impact on human brain development and function. However, in western industrial countries omega-3 LC-PUFA in particular are often lacking in diets. Increasing evidence indicates that LC-PUFA imbalance or deficiencies may be associated with Attention Deficit/Hyperactivity Disorder (ADHD) through involvement in the dopaminergic corico-striatal metabolism. Preliminary study result suggest that dietary supplementation with LC-PUFA might be effective in the treatment of ADHD.

METHODS

This review summarizes the knowledge in terms of a hypothesized pathogenetic relationship between fatty acid metabolism and ADHD and discusses the possible clinical benefit of a primary or combined treatment with LC-PUFA.

RESULTS

Actually it is unclear whether a deficit in intake or metabolism of LC-PUFA may play a major role in the pathogenesis of ADHD. Moreover treatment studies yielded conflicting results. A combination of Omega-3 and Omega-6 - fatty acids might attenuate the symptoms of ADHD significantly, thus making this dietary intake useful.

CONCLUSIONS

Considerable research has to be done in the future to identify ideal therapeutic combinations and dosages of various fatty acids, and to develop reliable ways of defining those individuals to benefit from this treatment access.

High dietary omega-6 fatty acids contribute to reduced docosahexaenoic acid in the developing brain and inhibit secondary neurite growth

Docosahexaenoic acid (DHA, 22:6omega-3) is a major polyunsaturated fatty acid in the brain and is required in large amounts during development. Low levels of DHA in the brain are associated with functional deficits. The omega-3 fatty acids are essential nutrients and their metabolism and incorporation in developing brain depends on the composition of dietary fat. We assessed the importance of the intake of the omega-3 fatty acid, 18:3omega-3 and the balance with the omega-6 fatty acid, 18:2omega-6, and the effects of dietary arachidonic acid (20:4omega-6) and DHA in milk diets using the piglet as a model of early infant nutrition. Piglets were fed (% energy) 1.2% 18:2omega-6 and 0.05% 18:3omega-3 (deficient), 10.7% 18:2omega-6 and 1.1% 18:3omega-3 (contemporary), 1.2% 18:2omega-6 and 1.1% 18:3omega-3 (evolutionary), or the contemporary diet with 0.3% 20:4omega-6 and 0.3% DHA (supplemented) from birth to 30 days of age. Our results show that a contemporary diet, high in 18:2omega-6 compromises DHA accretion and leads to increased 22:4omega-6 and 22:5omega-6 in the brain. However, an evolutionary diet, low in 18:2omega-6, supports high brain DHA. DHA supplementation effectively increased DHA, but not the intermediate omega-3 fatty acids, 20:5omega-3 and 22:5omega-3. Using primary cultures of cortical neurons, we show that 22:5omega-6 is efficiently acylated and preferentially taken up over DHA. However, DHA, but not 22:5omega-6 supports growth of secondary neurites. Our results suggest the need to consider whether current high dietary omega-6 fatty acid intakes compromise brain DHA accretion and contribute to poor neurodevelopment.

Cystic Fibrosis and Nutrition: Linking Phospholipids and Essential Fatty Acids with Thiol Metabolism

Cystic fibrosis (CF) is the most common lethal inherited disorder among Caucasians and results from mutation in the gene encoding the CF transmembrane conductance regulator. In addition to its multisystem clinical effects, the disease is characterized by increased proinflammatory mediators and oxidant stress, and systemic redox imbalance with reduced glutathione (GSH), together with alterations in circulating and tissue (n-6) and (n-3) fatty acids, particularly a decrease in docosahexaenoic acid. The metabolism of phospholipids and fatty acids is closely related to GSH through the methionine-homocysteine cycle, in which choline via betaine provides methyl groups to regenerate S-adenosylmethionine, important in generating phosphatidylcholine and amino acid precursors for GSH. Current research focuses both on fatty acid supplementations to normalize altered (n-6) to (n-3) fatty acid balance and decrease generation of (n-6) fatty acid-derived inflammatory mediators, and strategies to improve oxidant defenses and redox balance. However, further research is needed before such strategies can be included in clinical care of individuals with CF.

Prenatal long-chain polyunsaturated fatty acid status: the importance of a balanced intake of docosahexaenoic acid and arachidonic acid

This review addresses the effect of prenatal long-chain polyunsaturated fatty acid (LCPUFA) status on neurodevelopmental outcome. It focuses on the major LPCUFA doxosahexaenoic acid (DHA; 22:6omega3) and arachidonic acid (AA; 20:4omega6). Due to enzymatic competition high DHA intake results in lower tissue levels of AA. LCPUFA accumulation in the brain starts early and increases during the third trimester. Initially brain AA-accretion exceeds DHA-accretion; after term age DHA-accretion surpasses AA-accretion. Animal studies indicated that early omega3-depletion results in poorer developmental outcome. They also showed that early omega3-supplementation had no effect on cognitive outcome, promotes visual development and impairs auditory and motor development. Only limited human data are available. Correlational studies suggest that neonatal AA status shows a positive relation with early neurodevelopmental outcome and that neonatal DHA status also might be correlated with improved outcome beyond infancy. Results of human intervention studies are equivocal: most studies were unable to demonstrate a positive effect of prenatal omega3-supplementation. It is concluded that only limited evidence exists to support the notion that prenatal omega3-supplementation favours developmental outcome. Caution is warranted for an unbalanced high DHA intake during the first two trimesters of pregnancy, i.e., DHA without additional AA supplementation.

Trans fatty acids in maternal milk lead to cardiac insulin resistance in adult offspring

OBJECTIVE

Trans fatty acids (TFAs) are derived from vegetable oil hydrogenation and can be found in most manufactured food products. Our main objective was to evaluate the effects of TFA consumption by lactating dams on cardiac glucose metabolism of adult offspring by analyzing glucose transporter-4 in the left ventricle. To investigate the energy homeostasis, insulin sensitivity and hepatic glycogen content were also measured.

METHODS

Lactating Wistar rats were divided into a control group or a TFA group. The control group received a diet containing soybean oil, and the TFA group received a diet containing partially hydrogenated vegetable oil (total trans concentration of about 10.58 mg/g, 11.75%, of total fat) throughout the lactation period. At weaning, pups from both groups received a standard chow until 60 d of age, at which time the quantity of glucose transporter-4 in the left ventricle and hepatic glycogen were measured. Moreover, insulin sensitivity was analyzed by assessing the insulin/glucose ratio and the homeostatic model assessment index.

RESULTS

TFA consumption by the pups during lactation led to a significant decrease in the cardiac content of glucose transporter-4 (P < 0.05) and in the hepatic content of glycogen (P < 0.05). Moreover, we observed impaired insulin sensitivity in the TFA group (insulin/glucose ratio and homeostatic model assessment index, P < 0.05) in adulthood.

CONCLUSION

Our data suggest that the consumption of hydrogenated fat, rich in TFAs, by the mothers during the lactation period caused cardiac insulin resistance in the adult progeny, thus reinforcing the hypothesis that early adaptations may cause deleterious consequences later in life.

Fish oil prevents essential fatty acid deficiency and enhances growth: clinical and biochemical implications

Fish oil, a rich source of omega-3 fatty acids, has never been used as the sole source of lipid in clinical practice for fear of development of essential fatty acid deficiency, as it lacks the believed requisite levels of linoleic acid, an omega-6 fatty acid. The objectives of this study were to establish biochemical standards for fish oil as the sole fat and to test the hypothesis that fish oil contains adequate amounts of omega-6 fatty acids to prevent essential fatty acid deficiency. Forty mice were divided into 2 groups that were either pair fed or allowed to eat ad libitum. In each group, 4 subgroups of 5 mice were fed 1%, 5%, and 10% fish oil diets by weight or a control soybean diet for 9 weeks. Blood was collected at 4 time points, and fatty acid analysis was performed. Food intake and weight status were monitored. All groups but the pair-fed 1% fish oil group gained weight, and the 5% fish oil group showed the highest caloric efficiency in both pair-fed and ad libitum groups. Fatty acid profiles for the 1% fish oil group displayed clear essential fatty acid deficiency, 5% fish oil appeared marginal, and 10% and soybean oil diets were found to prevent essential fatty acid deficiency. Fish oil enhances growth through higher caloric efficiency. We established a total omega-6 fatty acid requirement of between 0.30% and 0.56% of dietary energy, approximately half of the conventionally believed 1% as linoleic acid. This can presumably be attributed to the fact that fish oil contains not only a small amount of linoleic acid, but also arachidonic acid, which has greater efficiency to meet omega-6 fatty acid requirements.

The declaration of nutrition, health, and intelligence for the child-to-be

The Declaration of Nutrition, Health, and Intelligence for the Child-to-be is an urgent cry from the unborn child for a life-span of nutrients for physical and mental wellness. It is a proclamation of paramount importance for everyone involved in child development: parents, health professionals, teachers, government agencies, all producers of food--and children, so they may learn how to feed themselves well. The Declaration of Olympia on Nutrition and Fitness, 1996, came from a group pf nutritional scientists and medical doctors to commemorate the Olympic Games' 100th anniversary. They based it on the health principles of Hippocrates: genetics, the age of the individual, the powers of various foods, and exercise. Following today's vast wealth of nutritional research and expressing it with my teaching experience, I have revitalized the Declaration of Olympia by writing from the heart of the little learner and the hope of the child-to-be. The nutrients implicated in healthy reproduction and lifelong health include B vitamins, particularly B1, B6, folate, B1312 antioxidants, particularly vitamins C and E: minerals such as iron, zinc, magnesium, selenium, iodine, and copper; and essential fatty acids, particularly DHA. These nutrients also lower the risk of neural tube defects: autism, dyslexia, Down's syndrome: childhood cancers, obesity, and defective fetal cell membranes associated with maternal diabetes. Our metabolism is hugely influenced also by activity and by affection. Today's foods are often processed beyond the cells' recognition and can result in neurological and physical morbidity and mortality. A diet of unprocessed free-range animals and seafood: legumes, deep-colored vegetables and fruits: nuts, seeds, and whole grains, germ and bran, reinstates nutritional potency.

Maternal n-3, n-6, and trans fatty acid profile early in pregnancy and term birth weight: a prospective cohort study

BACKGROUND

Maternal n-3, n-6, and trans fatty acids are claimed to affect fetal growth, yet evidence is limited.

OBJECTIVE

We investigated the association between maternal n-3, n-6, and trans fatty acids measured early in pregnancy and fetal growth.

DESIGN

Amsterdam pregnant women (n = 12 373) were invited to complete a questionnaire (response 67%) and donate blood around the 12th pregnancy week for nutrient analysis. For 4336 women, fatty acid concentrations were measured in plasma phospholipids (gas-liquid chromatography). Associations of these concentrations with birth weight and small-for-gestational-age (SGA) risk were analyzed (liveborn singleton term deliveries, n = 3704).

RESULTS

Low concentrations of individual n-3 fatty acids and 20:3n-6, the precursor of arachidonic acid (20:4n-6), but high concentrations of the other n-6 fatty acids and the main dietary trans fatty acid (18:1n-9t) were associated with lower birth weight (estimated difference in univariate analysis -52 to -172 g for extreme quintile compared with middle quintile). In general, SGA risk increased accordingly. After adjustment for physiologic, lifestyle-related and sociodemographic factors, low concentrations of most n-3 fatty acids and 20:3n-6 and high concentrations of 20:4n-6 remained associated with lower birth weight (-52 to -57 g), higher SGA risk, or both (odds ratios: 1.38-1.50). Infants of the 7% of women with the most adverse fatty acid profile were on average 125 g lighter and twice as likely to be small for gestational age.

CONCLUSION

An adverse maternal fatty acid profile early in pregnancy is associated with reduced fetal growth, which, if confirmed, gives perspective for the dietary prevention of lower birth weight.

The antidepressant role of dietary long-chain polyunsaturated n-3 fatty acids in two phases in the developing brain

In this work we investigated the effect from fish oil (FO) supplementation, rich in n-3 fatty acids, on an antidepressant effect on adult rats in Phase A (supplementation during pregnancy and lactation) and phase B (supplementation during post-weaning until adulthood). During Phase A, female rats, used as matrix to obtain male rats, were divided in three groups: FO (daily supplemented), CF (coconut fat daily supplemented) and control (not supplemented). Our results showed that adult rats whose mothers were supplemented with FO during Phase A and rats supplemented during phase B demonstrated a significantly decreased immobility time when compared to control and CF groups. There was no difference in neither motor activity nor anxiety behavior in the three groups excluding false positive results. Our results suggest that n-3 fatty acids supplementation during Phases A and B had a beneficial effect on preventing the development of depression-like behavior in adult rats.

Essential n-3 fatty acids in pregnant women and early visual acuity maturation in term infants

BACKGROUND

Docosahexaenoic acid (DHA) is important to neural development. Whether DHA intakes are low enough in some pregnant women to impair infant development is uncertain.

OBJECTIVE

We sought to determine whether DHA deficiency occurs in pregnant women and contributes to poor infant development.

DESIGN

Biochemical cutoffs, dietary intakes, or developmental scores indicative of DHA deficiency are not defined. Infant development has a distribution in which an individual's potential development is unknown. This was a randomized intervention to establish a distribution of developmental scores for infants of women with DHA intakes considered to be above requirements against which to compare the development of infants of mothers consuming their usual diet. DHA (400 mg/d; n = 67) or a placebo (n = 68) was consumed by the women from 16 wk gestation until delivery. We determined maternal red blood cell ethanolamine phosphoglyceride fatty acids, dietary intakes at 16 and 36 wk gestation, and infant visual acuity at 60 d of age.

RESULTS

We described an approach to identify DHA deficiency when biochemical and functional markers of deficiency are unknown. In multivariate analyses, infant visual acuity was related to sex (beta = 0.660, SE = 0.93, and odds ratio = 1.93) and maternal DHA intervention (beta = 1.215, SE = 1.64, and odds ratio = 3.37). More infant girls in the placebo than in the DHA intervention group had a visual acuity below average (P = 0.048). Maternal red blood cell ethanolamine phosphoglyceride docosatetraenoic acid was inversely related to visual acuity in boys (rho = -0.37, P < 0.05) and girls (rho = -0.48, P < 0.01).

CONCLUSIONS

These studies suggest that some pregnant women in our study population were DHA-deficient.

Beneficial effects of a polyunsaturated fatty acid on infant development: evidence from the inuit of arctic Quebec

OBJECTIVES

To examine the relation of cord plasma docosahexaenoic acid (DHA) concentration to gestation length, birth size, growth, and infant visual acuity, cognitive, and motor development and the effects on growth and development associated with DHA intake from breast-feeding.

STUDY DESIGN

DHA, other polyunsaturated fatty acids, and 3 environmental contaminants (polychlorinated biphenyls, mercury, and lead) were assessed in cord plasma and maternal plasma and milk in 109 Inuit infants in Arctic Quebec. Multiple regression was used to examine the relation of cord DHA and DHA from breast-feeding on growth and development at 6 and 11 months, after controlling for contaminant exposure and other potential confounders.

RESULTS

Higher cord DHA concentration was associated with longer gestation, better visual acuity and novelty preference on the Fagan Test at 6 months, and better Bayley Scale mental and psychomotor performance at 11 months. By contrast, DHA from breast-feeding was not related to any indicator of cognitive or motor development in this full-term sample.

CONCLUSIONS

The association of higher cord DHA concentration with more optimal visual, cognitive, and motor development is consistent with the need for substantial increases in this critically important fatty acid during the third trimester spurt of synaptogenesis in brain and photoreceptor development.

Systematic review of fatty acid composition of human milk from mothers of preterm compared to full-term infants

BACKGROUND

Fatty acid composition of human milk serves as guidance for the composition of infant formulae. The aim of the study was to systematically review data on the fatty acid composition of human milk of mothers of preterm compared to full-term infants.

METHODS

An electronic literature search was performed in English (Medline and Medscape) and German (SpringerLink) databases and via the Google utility. Fatty acid compositional data for preterm and full-term human milk were converted to differences between means and 95% confidence intervals.

RESULTS

We identified five relevant studies publishing direct comparison of fatty acid composition of preterm versus full-term human milk. There were no significant differences between the values of the principal saturated and monounsaturated fatty acids. In three independent studies covering three different time points of lactation, however, docosahexaenoic acid (DHA) values were significantly higher in milk of mothers of preterm as compared to those of full-term infants, with an extent of difference considered nutritionally relevant.

CONCLUSION

Higher DHA values in preterm than in full-term human milk underlines the importance of using own mother's milk for feeding preterm babies and raises the question whether DHA contents in preterm formulae should be higher than in formulae for full-term infants.

Trans fatty acids from milk of Brazilian mothers of premature infants

AIM

The presence of trans fatty acids (TFA) in human milk may be a concern because of their possible adverse nutritional effects on the infant development. TFA may interfere with the metabolism of long-chain polyunsaturated fatty acids (LC-PUFA). Marked variation in TFA of milk appears in different populations. No data have yet been reported in Brazil, particularly as regards the milk of mothers of premature infants. Because of the importance of LC-PUFA in infant growth and development, we investigated the fatty acids composition of the milk of Brazilian mothers of premature infants.

METHODS

We analysed, through gas-liquid chromatography, the content of fatty acids of 37 milk samples obtained from mothers delivering prematurely. Samples were collected from colostrum and mature milk of exclusive breastfeeding.

RESULTS

All samples contained trans isomers of C18:1 acid with trans isomers of PUFA in lower proportion. The percentage of TFA (mean +/- SD) in the colostrum was 2.34 +/- 0.75, and 2.19 +/- 0.47 in the mature milk. For the LC-PUFA these values were 0.97 +/- 0.34 in the colostrum and 0.66 +/- 0.25 in the mature milk. The contents of total essential fatty acids and PUFA n-6 were inversely correlated with TFA in colostrum and mature milk. We found a positive correlation between levels of arachidonic acid in mature milk and change in the children's height.

CONCLUSIONS

The study showed that the intake of TFA occupies an intermediate position between the values of North America and European countries, reflecting the ongoing transition to industrialised foods in Brazil.

Maternal dietary omega fatty acid intake and auditory brainstem-evoked potentials in Mexican infants born at term: cluster analysis

OBJECTIVE

To identify biological and socioeconomic factors associated with the neurological development of Mexican infants born at term, as measured by brainstem auditory-evoked potentials (BAEPs).

SUBJECTS AND METHODS

We conducted a cohort study among 76 women with low risk pregnancies recruited in their third trimester of pregnancy and followed their infants until 12 months of age. BAEP tests were conducted on the infants before 3 months of age during physiologic sleep, using 100 msec bipolar clicks. Maternal dietary intake was evaluated by food frequency questionnaire. Two BAEP groups (short latency, long latency) were identified by cluster analysis. The association between BAEP group and maternal PUFAs was estimated using logistic regression models adjusted for socioeconomic and biological factors.

RESULTS

Short latency BAEPs were associated with a maternal diet rich in arachidonic acid (OR=3.63, 95% CI 1.23-10.67) after adjusting for age (in days) sex, head circumference and gestational age but was not significantly associated to a maternal diet rich in docosahexaenoic acid (DHA).

CONCLUSIONS

Our results suggest the importance of arachidonic acid intake during pregnancy for short latency BAEPs and adequate fetal myelination.

Soy-based infant formula supplemented with DHA and ARA supports growth and increases circulating levels of these fatty acids in infants

Healthy term infants (n = 244) were randomized to receive: (1) control, soy-based formula without supplementation or (2) docosahexaenoic acid-arachidonic acid (DHA + ARA), soy-based formula supplemented with at least 17 mg DHA/100 kcal (from algal oil) and 34 mg ARA/100 kcal (from fungal oil) in a double-blind, parallel group trial to evaluate safety, benefits, and growth from 14 to 120 days of age. Anthropometric measurements were taken at 14, 30, 60, 90, and 120 days of age and 24-h dietary and tolerance recall were recorded at 30, 60, 90, and 120 days of age. Adverse events were recorded throughout the study. Blood samples were drawn from subsets of 25 infants in each group. Capillary column gas chromatography was used to analyze the percentages of fatty acids in red blood cell (RBC) lipids and plasma phospholipids. Compared with the control group, percentages of fatty acids such as DHA and ARA in total RBC and plasma phospholipids were significantly higher in infants in the DHA + ARA group at 120 days of age (P < 0.001). Growth rates did not differ significantly between feeding groups at any assessed time point. Supplementation did not affect the tolerance of formula or the incidence of adverse events. Feeding healthy term infants soy-based formula supplemented with DHA and ARA from single cell oil sources at concentrations similar to human milk significantly increased circulating levels of DHA and ARA when compared with the control group. Both formulas supported normal growth and were well tolerated.

Fatty acids and early human development

Fatty acids play central roles in growth and development through their roles in membrane lipids, as ligands for receptors and transcription factors that regulate gene expression, precursor for eicosanoids, in cellular communication, and through direct interactions with proteins. Adverse fatty acid supplies during fetal and child development alter the fatty acid composition of membrane phospholipids and storage triglycerides with the potential to disrupt cellular environments, and program structure and function. Maternal fatty acid nutrition during pregnancy and lactation determines the transfer of essential n-6 and n-3, and non-essential trans fatty acids via the placenta and through human milk. Poor maternal docosahexaenoic acid (DHA) status increases risk of inadequate DHA to support brain and retinal development, delaying or limiting neural and visual system development. The implications of recent changes in the dietary fatty acids on maternal to infant fatty acid transfer, including the composition of human milk has been insufficiently studied.

A putative link of PUFA, GPR40 and adult-born hippocampal neurons for memory

Long chain polyunsaturated fatty acids (PUFA) such as docosahexaenoic and arachidonic acids, which are enriched in the brain, are important for multiple aspects of neuronal development and function including neurite outgrowth, signal transduction and membrane fluidity. Recent studies show that PUFA are capable of improving hippocampal long-term potentiation, learning ability of aged rats, and cognitive function of humans with memory deficits, although the underlying mechanisms are unknown. There have been several reports studying physiological roles of G-protein coupled receptor 40 (GPR40) in the pancreas, but no studies have focused on the function of GPR40 in the brain. As GPR40 was recently identified in neurons throughout the brain, it is probable that certain PUFA may act, as endogenous ligands, on GPR40 at their cell surface. However, the effects of PUFA upon neuronal functions are still not clearly understood. Here, although circumferential, a combination of in vitro and in vivo data is introduced to consider the effects of docosahexaenoic and arachidonic acids on brain functions. GPR40 was found in the newborn neurons of the normal and postischemic hippocampi of adult macaque monkeys, while the positive effects of PUFA upon Ca(2+) mobilization and cognitive functions were demonstrated in both GPR40 gene-transfected PC12 cells and human subjects with memory deficits. The purpose of this review is to propose a putative link among PUFA, GPR40, and hippocampal newborn neurons by discussing whether PUFA can improve memory functions through GPR40 activation of adult-born neurons. At present, little is known about PUFA requirements that make possible neurogenesis in the adult hippocampus. However, the idea that 'PUFA-GPR40 interaction might be crucial for adult neurogenesis and/or memory' should be examined in detail using various experimental paradigms.

In utero and postnatal exposure to long chain (n-3) PUFA enhances intestinal glucose absorption and energy stores in weanling pigs

The aim of this research was to determine whether feeding gestating and lactating sows (n-3) PUFA [eicosapentaenoic acid (EPA) and/or docosahexenoic acid (DHA)] or coconut fat (saturated fat) influences ex vivo glucose absorption in the proximal jejunum and glucose and glycogen concentration of liver and muscle of their offspring at weaning. Sows were fed 1 of 4 diets for 150 d, which included the entire gestation and lactation periods. The diets consisted of basal corn/soybean meal (CONT), CONT + protected EPA and DHA-rich fish oil (PFO), CONT + DHA Gold fat (DHAGF), and CONT + coconut fat (COCO). All tissues were collected from piglets (n = 4 per treatment) following a 24-h period of food deprivation, which was initiated at weaning. Proximal jejunum samples were mounted in modified Ussing chambers for transport determinations. Relative to the CONT (7 muA/cm(2)), active glucose transport was greater (P = 0.013) in piglets from sows fed the PFO (30 microA/cm(2)) and DHAGF (40 microA/cm(2)) diets, but not the COCO diet (19 microA/cm(2); pooled SEM = 5). Likewise, jejunum expression of glucose transporter 2 and sodium glucose transporter 1 protein tended (P < 0.10) to be greater in piglets from dams fed the PFO and DHAGF diets, as did AMP-activated protein kinase activity. Piglets' muscle glycogen was greater than in CONT (34 +/- 5.2 mg/g wet tissue) only in piglets from dams fed the DHAGF (46 +/- 5.2 mg/g wet tissue; P < 0.05). These results indicate that (n-3) PUFA, particularly DHA, improves intestinal glucose absorption and muscle glycogen concentrations in newly weaned pigs. These findings may also have important implications for human mothers and infants.

Human milk: maternal dietary lipids and infant development

Human milk provides all the dietary essential fatty acids, linoleic acid (LA; 18:2n-6) and alpha-linolenic acid (18:3n-3), as well as their longer-chain more-unsaturated metabolites, including arachidonic acid (20:4n-6) and DHA (22:6n-3) to support the growth and development of the breast-fed infant. Human milk levels of LA have increased in Westernized nations from mean levels (g/100 g total fatty acids) of 6 to 12-16 over the last century, paralleling the increase in dietary intake of LA-rich vegetable oils. DHA levels (g/100 g total milk fatty acids) vary from 1% and are lowest in countries in which the intake of DHA from fish and other animal tissue lipids is low. The role of DHA in infant nutrition is of particular importance because DHA is accumulated specifically in the membrane lipids of the brain and retina, where it is important to visual and neural function. An important question is the extent to which many human diets that contain low amounts of n-3 fatty acids may compromise human development. The present paper reviews current knowledge on maternal diet and human milk fatty acids, the implications of maternal diet as the only source of essential fatty acids for infant development both before and after birth, and recent studies addressing the maternal intakes and milk DHA levels associated with risk of low infant neural system maturation.

Dietary lipids in early development: relevance to obesity, immune and inflammatory disorders

PURPOSE OF REVIEW

Regardless of social, cultural and behavioural environments, obesity is usually caused by an energy intake above requirements, which is accommodated by the accumulation of triacylglycerols. The composition of dietary fat impacts tissue fatty acids, which are important modulators of multiple cell functions, including differentiation, lipogenesis, lipolysis and the generation of inflammatory mediators. This review focuses on the possible contribution of fatty acids to the link between obesity and inflammation in young children.

RECENT FINDINGS

Adipose tissue is a complex organ that functions to regulate fatty acid balance, clearing and releasing fatty acids, and synthesizing protein and signaling molecules that act as local and distant inflammatory mediators. Obesity, even in young children, is associated with increased circulating inflammatory mediators. As a result of changes in dietary fat compositions, infants are exposed to high n-6, saturated and trans fatty acids and low n-3 fatty acids. Saturated and trans fatty acids increase and n-3 fatty acids decrease many metabolic and inflammatory changes that accompany diet-induced triacylglycerol storage. High linoleic acid is associated with increased oxidative stress.

SUMMARY

There is a biological reason to consider that dietary fatty acids may contribute to oxidative stress and heightened inflammatory responses in young children.

Dietary polyunsaturated fat that is low in (n-3) and high in (n-6) fatty acids alters the SNARE protein complex and nitrosylation in rat hippocampus

Docosahexaenoic acid [DHA, 22:6(n-3)] is enriched in brain membrane phospholipids and is important to brain development and function through its influence on neurite outgrowth and neurotransmitter secretion. Fusion of intracellular vesicles with the plasma membrane involving SNARE [soluble N-ethylmaleimide-sensitive fusion (NSF) protein attachment protein receptor] protein assembly, membrane fusion, and then disassembly are events common in membrane extension and neurotransmitter release. We determined whether feeding an (n-3) fatty acid-deficient diet, known to reduce brain phospholipid DHA, alters SNARE protein and SNARE complex expression or protein nitrosylation in the hippocampus of rats. Female rats were fed diets with 1.3 or 0.02% energy (n-3) alpha-linolenic acid from 2 wk before gestation then throughout gestation and lactation (n = 8/diet), and the male offspring were weaned to the maternal diet. Hippocampus phospholipid fatty acids and SNARE proteins were determined in male offspring at 90 d of age. Hippocampus phospholipid DHA was lower and (n-6) docosapentaenoic acid [DPA, 22:5(n-6)] was higher in the (n-3) fatty acid-deficient rats compared with the control group (P < 0.05). Multiplex Western blots using antibodies to syntaxin, synaptosome-associated protein of 25kDa (SNAP-25), and complexin II, showed higher ternary SNARE complexes but no differences in syntaxin, SNAP-25, or complex II expression in hippocampus of the (n-3) fatty acid-deficient rats compared with the control group (P < 0.05). S-nitrosylation of syntaxin was also significantly lower in the (n-3) fatty acid-deficient rats than in the control group. These studies suggest that altered SNARE complex binding or disassembly could be important in explaining the diverse cellular events associated with altered tissue DHA.

Enhancing parenteral nutrition therapy for the neonate

The neonate receiving parenteral nutrition (PN) therapy requires a physiologically appropriate solution in quantity and quality given according to a timely, cost-effective strategy. Maintaining tissue integrity, metabolism, and growth in a neonate is challenging. To support infant growth and influence subsequent development requires critical timing for nutrition assessment and intervention. Providing amino acids to neonates has been shown to improve nitrogen balance, glucose metabolism, and amino acid profiles. In contrast, supplying the lipid emulsions (currently available in the United States) to provide essential fatty acids is not the optimal composition to help attenuate inflammation. Recent investigations with an omega-3 fish oil IV emulsion are promising, but there is need for further research and development. Complications from PN, however, remain problematic and include infection, hepatic dysfunction, and cholestasis. These complications in the neonate can affect morbidity and mortality, thus emphasizing the preference to provide early enteral feedings, as well as medication therapy to improve liver health and outcome. Potential strategies aimed at enhancing PN therapy in the neonate are highlighted in this review, and a summary of guidelines for practical management is included.

Evidence for the effect of omega-3 fatty acids on progression of age-related macular degeneration: a systematic review

BACKGROUND

As part of a larger systematic review on the effect of omega-3 fatty acids on eye health, the aim of this report was to appraise and synthesize the evidence for the effects of omega-3 fatty acids in slowing down the progression of age-related macular degeneration (AMD) and/or decreasing the rate of progression to advanced forms of AMD.

METHODS

A comprehensive search was undertaken in six databases (MEDLINE, PreMEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, CAB Health, and Dissertation Abstracts).

RESULTS

Two unique studies, one randomized clinical trial (RCT) and one prospective cohort study, satisfied the eligibility criteria and were included in the review. The RCT reported evidence on the effect of omega-3 fatty acids in slowing down the progression of AMD. The prospective cohort study addressed the question: what is the evidence that omega-3 fatty acids decrease the rate of progression to advanced forms of AMD?

CONCLUSIONS

Clinical research on this topic is scarce. Only two studies were eligible to be included in this review. Although one study result indicated efficacy of preventing AMD progression to its advanced form, this result needs to be duplicated and supported by future research.