n-3 fatty acids in the brain and retina: evidence for their essentiality

Neurodevelopment Is Dependent on Maternal Diet: Placenta and Brain Glucose Transporters GLUT1 and GLUT3

Glucose is the primary energy source for most mammalian cells and its transport is affected by a family of facilitative glucose transporters (GLUTs) encoded by the SLC2 gene. GLUT1 and GLUT3, highly expressed isoforms in the blood-brain barrier and neuronal membranes, respectively, are associated with multiple neurodevelopmental disorders including epilepsy, dyslexia, ADHD, and autism spectrum disorder (ASD). Dietary therapies, such as the ketogenic diet, are widely accepted treatments for patients with the GLUT1 deficiency syndrome, while ameliorating certain symptoms associated with GLUT3 deficiency in animal models. A ketogenic diet, high-fat diet, and calorie/energy restriction during prenatal and postnatal stages can also alter the placental and brain GLUTs expression with long-term consequences on neurobehavior. This review focuses primarily on the role of diet/energy perturbations upon GLUT isoform-mediated emergence of neurodevelopmental and neurodegenerative disorders.

N-3 PUFA Deficiency from Early Life to Adulthood Exacerbated Susceptibility to Reactive Oxygen Species-Induced Testicular Dysfunction in Adult Mice

Homeostasis of reactive oxygen species is required to maintain sperm maturation and capacitation. Docosahexaenoic acid (DHA) is accumulated in testicles and spermatozoa and has the ability to manipulate the redox status. The effects of dietary n-3 polyunsaturated fatty acid (n-3 PUFA) deficiency from early life to adulthood on the physiological and functional properties of males under the redox imbalance of testicular tissue deserve attention. The consecutive injection of hydrogen peroxide (H₂O₂) and tert-butyl hydroperoxide (t-BHP) for 15 days to induce oxidative stress in testicular tissue was used to elucidate the consequences of testicular n-3 PUFA deficiency. The results indicated that reactive oxygen species treatment in adult male mice with DHA deficiency in the testis could reduce spermatogenesis and disrupt sex hormone production, as well as trigger testicular lipid peroxidation and tissue damage. N-3 PUFA deficiency from early life to adulthood resulted in higher susceptibility to testicular dysfunction in the germinal function of supplying germ cells and the endocrine role of secreting hormones through the mechanism of aggravating mitochondria-mediated apoptosis and destruction of blood testicular barrier under oxidative stress, which might provide a basis for humans to reduce susceptibility to chronic disease and maintain reproductive health in adulthood through dietary interventions of n-3 PUFAs.

Methods to capture proteomic and metabolomic signatures from cerebrospinal fluid and serum of healthy individuals

Discovery of reliable signatures for the empirical diagnosis of neurological diseases-both infectious and non-infectious-remains unrealized. One of the primary challenges encountered in such studies is the lack of a comprehensive database representative of a signature background that exists in healthy individuals, and against which an aberrant event can be assessed. For neurological insults and injuries, it is important to understand the normal profile in the neuronal (cerebrospinal fluid) and systemic fluids (e.g., blood). Here, we present the first comparative multi-omic human database of signatures derived from a population of 30 individuals (15 males, 15 females, 23-74 years) of serum and cerebrospinal fluid. In addition to empirical signatures, we also assigned common pathways between serum and CSF. Together, our findings provide a cohort against which aberrant signature profiles in individuals with neurological injuries/disease can be assessed-providing a pathway for comprehensive diagnostics and therapeutics discovery.

Effect of long-chain polyunsaturated fatty acids in infant formula on long-term cognitive function in childhood: A systematic review and meta-analysis of randomised controlled trials

STUDY REGISTRATION

PROSPERO registration numbers CRD42018105196 and CRD42018088868.

Comparative Effect of Feeding Human Milk as Opposed to Formula on Visual Function and Ocular Anatomy

Background/Objective: Performance of ocular examinations on children who were breastfed, fed with formula, and combination of the two for the first 6 months of age. Subsequently, refractive errors, allergic conjunctivitis, and retinal nerve fiber layer (RNFL) thickness were evaluated. Materials and Methods: The present study included a total of 242 eyes of 121 children (aged 60-84 months, 65 males, 56 females) admitted to the outpatient clinic of our institution. The patients were divided into three groups according to their feeding pattern during their first 6 months postdelivery: breastfed children (Group 1, n = 40), children fed with a combination of breast and formula milk (Group 2, n = 41), and children exclusively fed with formula-milk (Group 3, n = 40). All patients underwent detailed ophthalmologic examinations, and measurements of the RNFLs were recorded. Results: No significant difference was observed between the groups in terms of refractive error. In Group 3, we found that allergic conjunctivitis was significantly higher than in the other groups. In addition, in Group 3, the thickness of the RNFL was found to be significantly higher in the superior quadrants of both the eyes of children than in Groups 1 and 2 (p < 0.05). Conclusions: We found that the type of feeding experienced by infants in their first 6 months has no effect on refractive error but has significant effects on both allergic conjunctivitis and RNFL. To determine the cause of this difference in the RNFL and to further validate the present study, future studies with larger patient groups and animal experiments are needed.

The effects of breastfeeding versus formula-feeding on cerebral cortex maturation in infant rhesus macaques

Breastfeeding is positively associated with several outcomes reflecting early brain development and cognitive functioning. Brain neuroimaging studies have shown that exclusively breastfed children have increased white matter and subcortical gray matter volume compared to formula-fed children. However, it is difficult to disentangle the effects of nutrition in breast milk from other confounding factors that affect brain development, particularly in studies of human subjects. Among the nutrients provided by human breast milk are the carotenoid lutein and the natural form of tocopherol, both of which are selectively deposited in brain. Lutein is the predominant carotenoid in breast milk but not in most infant formulas, whereas infant formulas are supplemented with the synthetic form of tocopherol. In this study, a non-human primate model was used to investigate the effects of breastfeeding versus formula-feeding, as well as lutein and natural RRR-α-tocopherol supplementation of infant formula, on brain maturation under controlled experimental conditions. Infant rhesus macaques (Macaca mulatta) were exclusively breastfed, or were fed infant formulas with different levels and sources of lutein and α-tocopherol. Of note, the breastfed group were mother-reared whereas the formula-fed infants were nursery-reared. Brain structural and diffusion MR images were collected, and brain T₂ was measured, at two, four and six months of age. The mother-reared breastfed group was observed to differ from the formula-fed groups by possessing higher diffusion fractional anisotropy (FA) in the corpus callosum, and lower FA in the cerebral cortex at four and six months of age. Cortical regions exhibiting the largest differences include primary motor, premotor, lateral prefrontal, and inferior temporal cortices. No differences were found between the formula groups. Although this study did not identify a nutritional component of breast milk that could be provided to infant formula to facilitate brain maturation consistent with that observed in breastfed animals, our findings indicate that breastfeeding promoted maturation of the corpus callosum and cerebral cortical gray matter in the absence of several confounding factors that affect studies in human infants. However, differences in rearing experience remain as a potential contributor to brain structural differences between breastfed and formula fed infants.

Effects of early-life malnutrition on neurodevelopment and neuropsychiatric disorders and the potential mechanisms

Lines of evidence have demonstrated that early-life malnutrition is highly correlated with neurodevelopment and adulthood neuropsychiatric disorders, while some findings are conflicting with each other. In addition, the biological mechanisms are less investigated. We systematically reviewed the evidence linking early-life nutrition status with neurodevelopment and clinical observations in human and animal models. We summarized the effects of special nutritious on neuropsychiatric disorders and explored the underlying potential mechanisms. The further understanding of the biological regulation of early-life nutritional status on neurodevelopment might shed light on precision nutrition at an integrative systems biology framework.

Chemical Characterization and Oxidative Stability of Medium- and Long-Chain Fatty Acid Profiles in Tree-Borne Seed Oils

This study was undertaken to evaluate chemical characteristics and oxidative stability of tree-borne seed oils. A total of 15 different fatty acids were identified in six tree-borne seed oils, which included seven types of saturated fatty acids, four types of monounsaturated fatty acids, and four types of polyunsaturated fatty acids. Japanese camphor tree (JCT) had a high content of medium-chain fatty acids (97.94 ± 0.04%), in which fatty acid composition was distinct from those of the other five plant seed oils. Overall, contents of tocopherols, a type of fat-soluble vitamin, ranged between 3.82 ± 0.04 mg/100 g and 101.98 ± 1.34 mg/100 g, respectively. Phytosterol contents ranged from 117.77 ± 1.32 mg/100 g to 479.45 ± 4.27 mg/100 g, respectively. Of all tree-borne seed oils, β-sitosterol was the phytosterol at the highest concentration. Contents of unsaponifiables were between 0.13 ± 0.08 and 2.01 ± 0.02, and values of acid, peroxide, and p-anisidine were between 0.79 ± 0.01 and 38.94 ± 0.24 mg KOH/g, 3.53 ± 0.21 and 127.67 ± 1.79 meq/kg, and 2.07 ± 0.51 and 9.67 ± 0.25, respectively. Oxidative stability of tree-borne seed oils was assessed through measurement of oxidation-induction periods. These results should serve as a foundation to identify the potential of tree-borne seed oils in industrial application as well as in providing fundamental data.

Omega-3 Fatty Acid Plasma Levels Before and After Supplementation: Correlations with Mood and Clinical Outcomes in the Omega-3 and Therapy Studies

OBJECTIVE

To examine fatty acid profiles, their response to omega-3 fatty acid (Ω3) supplementation, and associations with clinical status and treatment response in youth with mood disorders.

METHODS

In a placebo-controlled 2X2 design, 7-14 year-olds (N = 95) in parallel pilot trials (depression N = 72; bipolar N = 23) were randomly assigned to 12 weeks of Ω3 supplementation (1.4 g eicosapentaenoic acid [EPA], 0.2 g docosahexaenoic acid [DHA], and 0.27 g other Ω3 per day); psychoeducational psychotherapy (PEP); their combination; or placebo (mainly oleic and linoleic acid) alone. Blood was drawn at baseline (N = 90) and endpoint (n = 65). Fatty acid levels were expressed as percent of total plasma fatty acids. Correlational and moderator/mediator analyses were done with SPSS Statistics 23.

RESULTS

At baseline: (1) DHA correlated negatively with alpha-linolenic acid (ALA) (r = -0.23, p = 0.029); (2) Arachidonic acid (AA, Ω6) correlated negatively with global functioning (r = -0.24, p = 0.022); (3) Total Ω3 correlated negatively with age (r = -0.22, p = 0.036) and diastolic blood pressure (r = -0.31, p = 0.006). Moderation: Baseline ALA moderated response to Ω3 supplementation: ALA levels above the sample mean (lower DHA) predicted significantly better placebo-controlled response (p = 0.04). Supplementation effects: Compared to placebo, 2 g Ω3 per day increased EPA blood levels sevenfold and DHA levels by half (both p < 0.001). Body weight correlated inversely with increased EPA (r = -0.52, p = 0.004) and DHA (r = -0.54, p = 0.003) and positively with clinical mood response. Mediation: EPA increase baseline-to-endpoint mediated placebo-controlled global function and depression improvement: the greater the EPA increase, the less the placebo-controlled Ω3 improvement.

CONCLUSION

Ω3 supplementation at 2 g/day increases blood levels substantially, more so in smaller children. A possible U-shaped response curve should be explored.

The Effect of Supplementation of Long-Chain Polyunsaturated Fatty Acids During Lactation on Neurodevelopmental Outcomes of Preterm Infant From Infancy to School Age: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE

Long-chain polyunsaturated fatty acids, especially docosahexaenoic acid, have been suggested as a nutrition factor affecting visual and neurobehavioral development of preterm infants. Several randomized controlled trials (RCTs) have investigated the effect of supplementation of long-chain polyunsaturated fatty acids on preterm infants. We conducted a systematic review and meta-analysis to examine the efficacy of long-chain polyunsaturated fatty acid supplementation of formula or breast milk on the neurodevelopment outcomes of preterm infants.

METHODS

Two authors searched PubMed and Cochrane Library (CENTRAL) for RCTs assessing efficacy of long-chain polyunsaturated fatty acids supplementation on the neurobehavioral and development outcomes of preterm infant. Human RCTs which supplemented long-chain polyunsaturated fatty acids during lactation and assessed neurodevelopment were included. The quality of each RCT was assessed, and the results of eligible trials were included in the systematic review and meta-analysis.

RESULTS

We included 11 RCTs with 2272 total participants. Methodologic limitations existed to some extent in most RCTs that were included. Because the age of the participants from different trails was not the same, different scales and indexes had been assessed from different RCTs. Our meta-analysis indicated a significant effect of long-chain polyunsaturated fatty acids supplementation on the neurodevelopment of preterm infants assessed by the Mental Development Index of the Bayley Scales at one to three years of age versus the control groups.

CONCLUSION

Analysis of our consolidated data indicates that long-chain fatty acid supplementation results in a significant improvement in the neurodevelopment of preterm infants as assessed by the Mental Development Index at one to three years of age. The available evidence suggests that long-chain polyunsaturated fatty acid supplementation during lactation may accelerate the pace of neurodevelopment in preterm infants, although their final developmental outcome may be unchanged.

Effects of prenatal and/or postnatal supplementation with iron, PUFA or folic acid on neurodevelopment: update

Neurodevelopment has been linked, among other factors, to maternal and early infant diets. The objective of this review, which is part of the NUTRIMENTHE research project ‘The effect of diet on the mental performance of children’ (www.nutrimenthe.com), was to update current evidence on the effects of nutritional interventions such as iron, folic acid or n-3 long-chain polyunsaturated fatty acid (LCPUFA) supplementation during pregnancy and/or in early life on the mental performance and psychomotor development of children. In May 2014, we searched MEDLINE and The Cochrane Database of Systematic Reviews for relevant studies published since 2009. The limited updated evidence suggests that iron supplementation of infants may positively influence the psychomotor development of children, although it does not seem to alter their mental development or behaviour. The use of multivitamin-containing folic acid supplements during pregnancy did not benefit the mental performance of the offspring. Evidence from randomised controlled trials (RCT) did not show a clear and consistent benefit of n-3 LCPUFA supplementation during pregnancy and/or lactation on childhood cognitive and visual development. Caution is needed when interpreting current evidence, as many of the included trials had methodological limitations such as small sample sizes, high attrition rates, and no intention-to-treat analyses. Taken together, the evidence is still inconclusive. Large, high-quality RCT to assess the effects of supplementation with iron, LCPUFA or folic acid are still needed to further clarify the effects of these, and other nutrients, on neurodevelopment. Recent recommendations from scientific societies are briefly presented.

Active Lactobacillus rhamnosus LA68 or Lactobacillus plantarum WCFS1 administration positively influences liver fatty acid composition in mice on a HFD regime

Active administration of Lactobacilli positively influences liver fatty acid composition in mice on a HFD regime.

Fish oil diet in pregnancy and lactation reduces pup weight and modifies newborn hepatic metabolic adaptations in rats

PURPOSE

To determine the effects of a diet containing fish oil (FD) during pregnancy and lactation in rats on the metabolic adaptations made by the offspring during early extrauterine life and to compare it to an olive oil diet (OD).

METHODS

Rats were mated and randomly allocated to OD or FD containing 10 % of the corresponding oil. During lactation, litters were adjusted to eight pups per dam. Fetuses of 20 days and pups of 0, 1, 10, 20 and 30 days of age were studied.

RESULTS

Body weight and length were lower in pups of the FD group from birth. The diet, milk, pups' plasma and liver of FD group had higher proportions of n-3 LCPUFA, but the content of arachidonic acid (ARA) was lower. Plasma glucose was higher, but unesterified fatty acids, triacylglycerols (TAG), 3-hydroxybutyrate and liver TAG in 1-day-old pups were lower in the FD group, and differences in some of these variables were also found in pups up to 30 days old. Liver lipoprotein lipase activity and mRNA expression, and the expression of carnitine palmitoyl transferase I, acyl-CoA oxidase and 3-hydroxy 3-methyl glutaryl-CoA synthase increased more at birth in pups of the FD group, but the expression of sterol regulatory element binding protein-1c and Δ6-desaturase mRNA was lower in the FD group.

CONCLUSIONS

Maternal intake of high n-3 LCPUFA retards postnatal development, which could be the result of impaired ARA synthesis, and affects hepatic metabolic adaptations to extrauterine life.

Light, lipids and photoreceptor survival: live or let die?

Due to its constant exposure to light and its high oxygen consumption the retina is highly sensitive to oxidative damage, which is a common factor in inducing the death of photoreceptors after light damage or in inherited retinal degenerations. The high content of docosahexaenoic acid (DHA), the major polyunsaturated fatty acid in the retina, has been suggested to contribute to this sensitivity. DHA is crucial for developing and preserving normal visual function. However, further roles of DHA in the retina are still controversial. Current data support that it can tilt the scale either towards degeneration or survival of retinal cells. DHA peroxidation products can be deleterious to the retina and might lead to retinal degeneration. However, DHA has also been shown to act as, or to be the source of, a survival molecule that protects photoreceptors and retinal pigment epithelium cells from oxidative damage. We have established that DHA protects photoreceptors from oxidative stress-induced apoptosis and promotes their differentiation in vitro. DHA activates the retinoid X receptor (RXR) and the ERK/MAPK pathway, thus regulating the expression of anti and pro-apoptotic proteins. It also orchestrates a diversity of signaling pathways, modulating enzymatic pathways that control the sphingolipid metabolism and activate antioxidant defense mechanisms to promote photoreceptor survival and development. A deeper comprehension of DHA signaling pathways and context-dependent behavior is required to understand its dual functions in retinal physiology.

Prenatal exposure to polycyclic aromatic hydrocarbons and cognitive dysfunction in children

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants produced by combustion of fossil fuel and other organic materials. Both experimental animal and human studies have reported the harmful impacts of PAH compounds on fetal growth and neurodevelopment, including verbal IQ of children. Here, we have assessed the association between cognitive function of children and prenatal PAH exposures. The study is part of an ongoing, longitudinal investigation of the health effects of prenatal exposure to air pollution on infants and children in Krakow, Poland. The subjects in this report included 170 children whose mothers were enrolled to the study in the first or second trimester of pregnancy whose cord blood were tested for PAH-DNA adducts and who were assessed at age 7 using the Wechsler Intelligence Scale for Children-Revised (WISC-R). The outcome of a priori interest was depressed verbal IQ index (DepVIQ), which is the difference between WISC-R performance and verbal IQ scores. Prenatal PAH exposure was measured by cord blood PAH-DNA adducts, an individual dosimeter, integrating exposure from various sources of exposure over the gestational period. The estimated effect of prenatal PAH exposure on cognitive function was adjusted in multivariable regression for a set of potential confounders (child's gender, parity, maternal education, breastfeeding practice, environmental tobacco smoke (ETS), and postnatal PAH exposure). The prevalence of DepVIQ was significantly higher in children with detectable PAH-DNA adducts compared to those with undetectable adducts (13.7 vs. 4.4 %,). Binary multivariable regression documented that the relative risk of DepVIQ increased threefold with a ln-unit increase in cord blood adducts (relative risk (RR) = 3.0, 95 % confidence interval (CI) 1.3-6.8). Postnatal PAH exposure also increased the risk of DepVIQ (RR = 1.6, 95 % CI 1.1-2.5). Long-term exclusive breastfeeding (at least 6 months) showed a protective effect (RR = 0.3, 95 % CI 0.1-0.9). In conclusion, these results provide further evidence that PAHs are harmful to the developing fetal brain with effects extending through childhood, with implications for the academic success of the children.

Dietary approaches for management of cardio-vascular health- a review

Dietary patterns of consumers have changed and the importance of diet as a therapeutic adjunct in the form of nutraceuticals has become the trend of the millennium. Major contributory factor behind this trend is the idea of improving health by modifying the diet that is more attractive to the health conscious consumer as compared to drugs. According to a recent report of WHO, prevalence of cardio vascular disease has increased progressively in the past few years. It has been estimated that one-fifth of deaths in India are due to coronary heart disease that is inflicting at a much younger age in Indians than in the West. Such an insight suggests that cardiac health needs protection. Food products containing functional ingredients that are useful in controlling various different diseases are expected to provide health benefits. Recent research indicates that foods rich in omega-3 fatty acids, antioxidant vitamins and fibres may be beneficial for cardio-vascular health.

Omega-3 supplementation improves cognition and modifies brain activation in young adults

OBJECTIVE

The current study aimed to investigate the effects of eicosapentaenoic acid (EPA)-rich and docosahexaenoic acid (DHA)-rich supplementations on cognitive performance and functional brain activation.

DESIGN

A double-blind, counterbalanced, crossover design, with a 30-day washout period between two supplementation periods (EPA-rich and DHA-rich) was employed. Functional magnetic resonance imaging scans were obtained during performance of Stroop and Spatial Working Memory tasks prior to supplementation and after each 30-day supplementation period.

RESULTS

Both supplementations resulted in reduced ratio of arachidonic acid to EPA levels. Following the EPA-rich supplementation, there was a reduction in functional activation in the left anterior cingulate cortex and an increase in activation in the right precentral gyrus coupled with a reduction in reaction times on the colour-word Stroop task. By contrast, the DHA-rich supplementation led to a significant increase in functional activation in the right precentral gyrus during the Stroop and Spatial Working Memory tasks, but there was no change in behavioural performance.

CONCLUSIONS

By extending the theory of neural efficiency to the within-subject neurocognitive effects of supplementation, we concluded that following the EPA-rich supplementation, participants' brains worked 'less hard' and achieved a better cognitive performance than prior to supplementation. Conversely, the increase in functional activation and lack of improvement in time or accuracy of cognitive performance following DHA-rich supplementation may indicate that DHA-rich supplementation is less effective than EPA-rich supplementation in enhancing neurocognitive functioning after a 30-day supplementation period in the same group of individuals.

Selective blubber fatty acid mobilization in lactating gray seals (Halichoerus grypus)

During negative energy balance periods, fatty acids (FAs) are mobilized to cover the metabolic demands of the body. FAs from adipose tissue are selectively mobilized according to their carbon length (CL) and number of double bonds (DBs); however, studies in vivo have focused only on fasting and nonlactating animals. During lactation, UK gray seals fast for 18 d, mobilizing a large amount of lipid from blubber to sustain their own metabolic demands and the nutritional requirements of pups. We investigated FA mobilization in individual gray seal mothers from two UK colonies sampled in 2005 and 2006. Linear mixed-effects models were used to examine to what extent the mobilization observed from FAs in blubber can be explained as a function of FAs' CL and number of DBs. FAs were mobilized according to their structure, such that for a given CL, mobilization increased with the number of DBs, and for a given number of DBs, mobilization decreased as CL increased. This pattern of selective mobilization was very similar between colonies, although the relative amounts of component FAs in blubber at early lactation were different between them. FAs, which are considered crucial to pup development, were mobilized more than predicted by the model. This suggests that selective mobilization of FAs is not related solely to the physicochemical characteristics of the FAs but also to the needs of a growing pup.

Meta-analysis of LCPUFA supplementation of infant formula and visual acuity

BACKGROUND AND OBJECTIVE

Long-chain polyunsaturated fatty acids (LCPUFAs) are hypothesized to affect visual acuity development in infants. Randomized controlled trials (RCTs) have been conducted to assess whether supplementation of LCPUFAs of infant formulas affects infant visual acuity. This meta-analysis was conducted to evaluate whether LCPUFA supplementation of infant formulas improves infants' visual acuity.

METHODS

PubMed and PsycInfo were searched for RCTs assessing the efficacy of LCPUFA supplementation of infant formulas on infant visual acuity. RCTs assessing the effects of LCPUFA supplementation on visual acuity (by using either visual evoked potential or behavioral methods) in the first year of life were included in this meta-analysis. Our primary outcome was the mean difference in visual resolution acuity (measured in logarithm of minimum angle of resolution [logMAR]) between supplemented and unsupplemented infants. We also conducted secondary subgroup analyses and meta-regression examining the effects of LCPUFA dose and timing, preterm versus term birth status, and trial methodologic quality.

RESULTS

Nineteen studies involving 1949 infants were included. We demonstrated a significant benefit of LCPUFA supplementation on infants' visual acuity at 2, 4, and 12 months of age when visual acuity was assessed by using visual evoked potential and at 2 months of age by using behavioral methods. There was significant heterogeneity between trials but no evidence of publication bias. Secondary analysis failed to show any moderating effects on the association between LCPUFA supplementation and visual acuity.

CONCLUSIONS

Current evidence suggests that LCPUFA supplementation of infant formulas improves infants' visual acuity up to 12 months of age.

Drug Screening to Treat Early-Onset Eye Diseases: Can Zebrafish Expedite the Discovery?

The molecular basis of many early-onset eye diseases has been uncovered, but the number of available drug treatments for improving deteriorated vision is still scarce. Consequently, there is a high demand for new drugs to treat these diseases. This review first provides a brief synopsis of the use of zebrafish model for screening drugs with vision benefits. In particular, visual-motor response, the activity response of larvae to a change in light stimuli, is proposed to serve as a simple and efficient tool for screening drugs that may improve vision in various zebrafish visual mutants. The second part of the review discusses the identification of novel drug candidates, with particular emphasis on naturally derived chemicals including traditional Chinese medicines and nutritional therapies on retinal degenerative diseases. Many of these chemicals have been used in neuroprotection and/or have been consumed by many populations for good health and vision; thus, the screening of these chemicals with various zebrafish visual mutants would expedite the development of novel drugs for treating early-onset eye diseases.

The effects of maternal supplementation of polyunsaturated Fatty acids on visual, neurobehavioural, and developmental outcomes of the child: a systematic review of the randomized trials

Polyunsaturated fatty acid (PUFA) use in pregnancy has been promoted as beneficial for visual and neurobehavioural development in the fetus. However, no systematic review of the randomized trials has been conducted. The objective of this review was to evaluate potential advantages of this regiment by reviewing all randomized trials in pregnancy. Methods. Systematic review of randomized controlled studies comparing cognitive and visual achievements among infants whose mothers were treated and untreated with PUFA during gestation. Results. Nine studies met the inclusion criteria, three focusing on visual and six on neurobehavioural development. Due to differing outcome measurements in the infants, the studies could not be combined into a formal meta-analysis. Synthesizing the existing data, for both visual and neurobehavioural development, most studies could not show sustained benefits to infant cognition or visual development. Conclusion. At the present time a recommendation to change practice and supplement all expecting mothers with PUFA to improve offspring vision or neurobehavioural function is not supported by existing evidence.

Effect of exclusive breastfeeding on the development of children's cognitive function in the Krakow prospective birth cohort study

The main goal of the study was to assess the effect of exclusive breastfeeding on the neurodevelopment of children over a 7-year follow-up period and to test the hypothesis that the observed cognitive gain in breastfed children in the first years of life is a strong predictor of their cognitive development trajectory, which may be continued in later life. The analysis is based on data from the 7-year follow-up of 468 term babies (>36 weeks of gestation) born to non-smoking mothers participating in an ongoing prospective cohort study. The cognitive function of children was assessed by psychometric tests performed five times at regular intervals from infancy through the preschool age. The study included valid neurodevelopmental assessment of the children-443 participants were evaluated least twice; 425, three times; and 307, five times in the follow-up period. The association between the cognitive achievements of preschool age children and exclusive breastfeeding of various durations was performed using the generalized estimating equation longitudinal model, adjusted for major confounders such as maternal education, gender, parity, and weight gain in pregnancy. Children breastfed exclusively for up to 3 months had intelligence quotients (IQs) that were on average 2.1 points higher compared to the others (95% confidence interval (CI), 0.24-3.9); children breastfed for 4-6 months scored higher by 2.6 points (95% CI, 0.87-4.27); and the benefit for children breastfed even longer (>6 months) increased by 3.8 points (95% CI, 2.11-5.45). Other predictors were maternal education, gender of the child, having an older sibling, and weight gain during pregnancy. The results of the study support the WHO expert recommendations on exclusive breastfeeding for 6 months; moreover, they provide evidence that even a shorter duration of exclusive breastfeeding in early infancy produces beneficial effects on the cognitive development of children. The breastfeeding-related IQ gain observed already at the age of 1 was sustained through preschool age, and the difference in terms of IQ score between breastfed children and the reference group (mixed breastfeeding) held constant over the whole preschool period.

Cognitive function in 18-month-old term infants of the DIAMOND study: a randomized, controlled clinical trial with multiple dietary levels of docosahexaenoic acid

BACKGROUND

Studies investigating cognitive outcomes following docosahexaenoic acid (DHA) supplementation of infant formula yield conflicting results, perhaps due to inadequate dietary concentrations.

AIM

To determine the optimal DHA concentration in term formula to support cognitive maturation.

DESIGN

This was a double-masked, randomized, controlled, prospective trial. A total of 181 infants were enrolled at 1-9 days of age and assigned randomly to receive one of four term infant formulas with one of four levels of docosahexaenoic acid: Control (0% DHA), 0.32% DHA, 0.64% DHA, or 0.96% DHA. All DHA-supplemented formulas contained 0.64% arachidonic acid (ARA). Infants were fed the assigned formulas until 12 months of age. One hundred forty-one children completed the 12-month feeding trial and were eligible for this study. Cognitive function was assessed in 131 children at 18 months of age using the Bayley Scales of Infant Development II (BSID II).

RESULTS

There were no diet group differences on the Mental Development Index (MDI), the Psychomotor Development Index (PDI), or the Behavior Rating Scale (BRS) of the BSID II. However, when the scores of children who received any of the three DHA-supplemented formulas were combined and compared to control children, a significant difference emerged: the MDI scores of DHA-supplemented children were higher (104.1 v. 98.4; p=0.02).

CONCLUSIONS

These results suggest that dietary supplementation of DHA during the first year of life leads to enhanced cognitive development at 18 months of age. DHA concentration of 0.32% is adequate to improve cognitive function; higher concentrations did not confer additional benefit.

Retinal very long-chain PUFAs: new insights from studies on ELOVL4 protein

Compared with other mammalian tissues, retina is highly enriched in PUFA. Long-chain PUFA (LC-PUFA; C18-C24) are essential FAs that are enriched in the retina and are necessary for maintenance of normal retinal development and function. The retina, brain, and sperm also contain very LC-PUFA (VLC-PUFA; >C24). Although VLC-PUFA were discovered more than two decades ago, very little is known about their biosynthesis and functional roles in the retina. This is due mainly to intrinsic difficulties associated with working on these unusually long polyunsaturated hydrocarbon chains and their existence in small amounts. Recent studies on the FA elongase elongation of very long chain fatty acids-4 (ELOVL4) protein, however, suggest that VLC-PUFA probably play some uniquely important roles in the retina as well as the other tissues. Mutations in the ELOVL4 gene are found in patients with autosomal dominant Stargardt disease. Here, we review the recent literature on VLC-PUFA with special emphasis on the elongases responsible for their synthesis. We focus on a novel elongase, ELOVL4, involved in the synthesis of VLC-PUFA, and the importance of these FAs in maintaining the structural and functional integrity of retinal photoreceptors.

Protein restriction during pregnancy affects maternal liver lipid metabolism and fetal brain lipid composition in the rat

Suboptimal developmental environments program offspring to lifelong metabolic problems. The aim of this study was to determine the impact of protein restriction in pregnancy on maternal liver lipid metabolism at 19 days of gestation (dG) and its effect on fetal brain development. Control (C) and restricted (R) mothers were fed with isocaloric diets containing 20 and 10% of casein. At 19 dG, maternal blood and livers and fetal livers and brains were collected. Serum insulin and leptin levels were determinate in mothers. Maternal and fetal liver lipid and fetal brain lipid quantification were performed. Maternal liver and fetal brain fatty acids were quantified by gas chromatography. In mothers, liver desaturase and elongase mRNAs were measured by RT-PCR. Maternal body and liver weights were similar in both groups. However, fat body composition, including liver lipids, was lower in R mothers. A higher fasting insulin at 19 dG in the R group was observed (C = 0.2 +/- 0.04 vs. R = 0.9 +/- 0.16 ng/ml, P < 0.01) and was inversely related to early growth retardation. Serum leptin in R mothers was significantly higher than that observed in C rats (C = 5 +/- 0.1 vs. R = 7 +/- 0.7 ng/ml, P < 0.05). In addition, protein restriction significantly reduced gene expression in maternal liver of desaturases and elongases and the concentration of arachidonic (AA) and docosahexanoic (DHA) acids. In fetus from R mothers, a low body weight (C = 3 +/- 0.3 vs. R = 2 +/- 0.1 g, P < 0.05), as well as liver and brain lipids, including the content of DHA in the brain, was reduced. This study showed that protein restriction during pregnancy may negatively impact normal fetal brain development by changes in maternal lipid metabolism.

Three randomized controlled trials of early long-chain polyunsaturated Fatty Acid supplementation on means-end problem solving in 9-month-olds

This study examines whether feeding infants formula supplemented with long-chain polyunsaturated fatty acids (LCPUFA) improves cognitive function of 9-month-olds. Participants included 229 infants from 3 randomized controlled trials. Children received either formula supplemented with docosahexaenoic acid and arachidonic acid, or a control formula beginning at 1-5 days (12-month feeding study), or following 6 weeks (6-week-weaning study) or 4-6 months of breastfeeding (4-to 6-month weaning study). Infants were assessed with a 2-step problem solving task. In the 12-month feeding and 6-week weaning studies, supplemented children had more intentional solutions (successful task completions) and higher intention scores (goal-directed behaviors) than controls. These results suggest that LCPUFA supplementation improves means-end problem solving.

Schoolchildren, maternal nutrition and generating healthy brains: the importance of lifecycle education for fertility, health and peace

In order to generate healthy brains, the earlier in life that children develop a healthy lifestyle the better. At home and at school, with a good diet and physical activity, children need to experience and to understand the value of healthy metabolism. Continuous education is needed in lifecycle health, with awareness that the most vulnerable phase relates to reproduction. This is the way that most people can become parents of healthy children. Nutrient deficits, toxins, or uro-genital disease, often unnoticed, affect quality of sperm or ovum, and subsequent development. Early errors can have the most pronounced effect. Gene-switches are being set early in life. Any early flaw can be magnified by growth. Moreover children's habits become set and young couples are too busy to learn and adapt. Many are liable to unintended pregnancy. Adoption of a healthy lifestyle at a young age is the most reliable route to producing healthy babies. The mother's state throughout pregnancy, emotions/hormones included, naturally continues to powerfully affect her child's development, therefore future physical and mental health, behaviour and ability. There has recently been a serious increase in babies conceived by schoolchildren, as well as a shift by working women towards childbearing in their late thirties or more. A return towards childbearing in the twenties and early thirties can reduce risks for the child. The mother needs to build her appropriate body-stores--vitamins and minerals, proteins, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and other essential polyunsaturated fatty acids (PUFA)--to ensure optimal development of her child. Replenishment of reserves is important for maternal health and before bearing another child. A restorative time of three years is desirable. Governments and school teachers need to guide and encourage parents in this health education and practice, and to use their authority to achieve it in schools. Empowerment with knowledge is the one way to fend off the growing pandemic of mental ill health and related disorders, and to make the most of a nation's genetic potential. There could be no better investment financially, let alone in enhancing people's lives.

Nurturing the brain nutritionally and emotionally from before conception to late adolescence

Sound nurture requires skills concerning nutrition and emotions, skills that are particularly important in key stages relating to brain development. We are recognizing more clearly the way that serious changes from our hunter-gatherer waterside lifestyle are affecting both our diet and our emotional relationships: first the changes a few hundred generations ago in the agricultural revolution: and more recently in the industrial revolution. These effects have been aggravated in the last century by excessively profit-driven intensive farming, and recently by intensive food-marketing--particularly to children. People are gradually becoming aware how very susceptible is the most vulnerable stage of the lifecycle, the reproductive phase. From long before fertilization and conception, parental nutrition affects a person's development and health for life. Controlled trials show marked effects of nurture on the brain's subsequent acuity. Brain structure throughout development has become visible through modern scans, and also brain activity and mental response. The neural tube, forming at around 3 weeks, if undernourished may be inadequately sealed and demarcated, leading to incomplete interconnection between brain regions. Results vary, but can emanate as: autism or attention-deficit/hyperactivity-disorder (AD/HD); difficulty with relationships and social sense; poor self-control, with risk of violence. Evidence indicates that over 80% of current reproductive hazards, including infertility and malformations, might be prevented purely by sound all-round nurture. Between the embryonic stage and adulthood the brain makes several developmental spurts. Particularly during these spurts, sound nutrition and activity help the brain reach its full genetic potential for capacity, acuity, and connections between regions. From the beginning, hormones and nutrients, or their deficits, are setting gene-switches for life. Good bonding and feeding sets gene-switches positively; shock, stress or poor nutrition, negatively. Forceps delivery combined with serious early separation, correlates with over 4 times the risk of criminal violence by the age of 18. So disruptions of nurture set at risk not only body and brain but a person's very spirituality. Understanding of the biochemistry and epigenetics highlights our urgent need to learn from our evolutionary ways, not only of childbearing, but of a physically active life nourished by foods from the water and the wild.

Sensitive and vulnerable periods in the development of the visual system

In advanced mammals the visual system consists of a number of parallel channels for the efficient processing of different aspects of the visual scene. Much of the basic anatomical structure of the visual pathway is constructed before birth. A wave of maturation sweeps through the system, from the eye to the visual cortex, the correct formation of connections depending on precisely timed interactions between axons and their targets. Competition between growing axons (apparently dependent on spontaneous impulse activity in those axons), cell death (partly influenced by competition between those cells' axons), axon withdrawal, trophic interactions--these and other mechanisms play a part in constructing the visual pathway and laying down basic 'maps' of the visual field before birth. Disturbances in such processes might underlie disorders of the genesis of the nervous system. At the level of the visual cortex, synaptic plasticity continues after birth and may permit cortical neurons to refine their processing capacities on the basis of information provided by the visual environment. This makes the young animal vulnerable to disturbances of visual experience early in life, which can cause virtually irreversible deficits in stereoscopic vision, visual resolution and sensitivity to contrast (amblyopia) in adult life.

Sustained elevation of intracellular cGMP causes oxidative stress triggering calpain-mediated apoptosis in photoreceptor degeneration

Sustained elevation in cGMP and a concomitant increase in intracellular Ca(2+) levels in the rd1 photoreceptors are followed by a rapid loss of photoreceptors. In a murine-derived photoreceptor cell line, 661W, treated with the phosphodiesterase inhibitor IBMX or the cyclic GMP-gated channel agonist 8-bromo-cGMP, it was previously found that the induced cell death was mediated by calpain and caspase-3. Because oxidative stress is a common product of ionic imbalance or elevated Ca(2+), we tested the role of oxidative stress in cGMP-induced photoreceptor cell death. In the rd1 mouse retina, oxidative stress was found to precede calpain and caspase-3 activation. In 661W cells, the increase in intracellular cGMP and Ca(2+) resulted in the generation of reactive oxygen species (ROS), the activation of oxidative stress enzymes, and the activation of calpain, followed by apoptosis mediated by the effector caspase-3. All these events, including calpain activation, were ameliorated by docosahexanoic acid (DHA). The cell-permeable inhibitor of calpain, SJA6017, while inhibiting cell death, had no effect on the generation of oxidative stress. These results establish a central role for oxidative stress in cGMP-induced cell death and suggest a ROS-mediated sequential activation of signal transduction events, which provide targets for future treatment strategies.

Effect of thyme oil and thymol dietary supplementation on the antioxidant status and fatty acid composition of the ageing rat brain

The present study measured changes in antioxidant enzyme activity in, and the phospholipid fatty acid composition of the ageing rat brain and tested whether dietary supplementation with thyme oil or thymol could provide beneficial effects. There were significant declines in superoxide dismutase (EC 1.15.1.1) and glutathione peroxidase (EC 1.11.1.9) activities and the total antioxidant status in the untreated rats with age, while thyme-oil- and thymol-fed rats maintained significantly higher antioxidant enzyme activities and total antioxidant status. The proportions of 18: 2n−6, 20: 1n−9, 22: 4n−6 and 22: 5n−3 in the brain phospholipids resulting from all three dietary treatments were significantly higher in 28-month-old rats than in 7-month-old rats. Only 20: 1n−9 levels in 28-month-old thyme-oil- and thymol-treated rats were significantly higher than in the age-matched control. The proportion of 22: 6n−3 in brain phospholipids, which declined with age in control rats, was also significantly higher in rats given either supplement. This latter finding is particularly important as optimum levels of 22: 6n−3 are required for normal brain function. These results highlight the potential benefit of thyme oil as a dietary antioxidant.

Effect of docosahexaenoic acid intake on lipid peroxidation in diabetic rat retina under oxidative stress

Docosahexaenoic acid (DHA) plays an important role in visual function but has a highly oxidation-prone chemical structure. Therefore, we investigated how dietary DHA affects the generation of lipid peroxides in rat retina under oxidative stress in diabetes with/without vitamin E (VE) deficiency. Streptozotocin-induced (50 mg i.p./kg B.W.) diabetic Sprague-Dawley (SD) rats were assigned to four groups: (i) control/VE(+), (ii) DHA/VE(+), (iii) control/VE( - ) and (iv) DHA/VE( - ), and raised for 28 days. We then measured lipid peroxide levels in the retina, serum and liver. With a normal intake of VE, dietary DHA increased only the retinal level of thiobarbituric acid-reactive substances (TBARS) slightly. In contrast, in rats with VE deficiency, dietary DHA increased serum and liver lipid peroxide levels but not in the retina. These results suggest that dietary DHA does not necessarily promote lipid peroxidation in the retina even under high oxidative stress.

Fish oil and mental health: the role of n-3 long-chain polyunsaturated fatty acids in cognitive development and neurological disorders

Epidemiological and experimental studies have indicated that consumption of more n-3 long-chain polyunsaturated fatty acids may reduce the risk for a variety of diseases, including cardiovascular, neurological and immunological disorders, diabetes and cancer. This article focuses on the role of marine n-3 long-chain polyunsaturated fatty acids in brain functions, including the development of the central nervous system and neurological disorders. An overview of the major animal studies and clinical trials is provided here, focusing on fatty acid supplementation during pregnancy and infancy, and prevention and management of Alzheimer's disease, schizophrenia, depression and attention deficit hyperactive disorder. Although an optimal balance in n-3/n-6 long-chain polyunsaturated fatty acid ratio is important for proper neurodevelopment and cognitive functions, results from randomized controlled trials are controversial and do not confirm any useful effect of supplementation on development of preterm and term infants. The relationship between fatty acid status and mental disorders is confirmed by reduced levels of n-3 long-chain polyunsaturated fatty acids in erythrocyte membranes of patients with central nervous system disorders. Nevertheless, there are very little data supporting the use of fish oil in those patients. The only way to verify whether n-3 long-chain polyunsaturated fatty acids are a potential therapeutic option in the management and prevention of mental disorders is to conduct a large definitive randomized controlled trials similar to those required for the licensing of any new pharmacological treatment.

G protein-coupled receptor systems and their lipid environment in health disorders during aging

Cells, tissues and organs undergo phenotypic changes and deteriorate as they age. Cell growth arrest and hyporesponsiveness to extrinsic stimuli are all hallmarks of senescent cells. Most such external stimuli received by a cell are processed by two different cell membrane systems: receptor tyrosine kinases (RTKs) and G protein-coupled receptors (GPCRs). GPCRs form the largest gene family in the human genome and they are involved in most relevant physiological functions. Given the changes observed in the expression and activity of GPCRs during aging, it is possible that these receptors are directly involved in aging and certain age-related pathologies. On the other hand, both GPCRs and G proteins are associated with the plasma membrane and since lipid-protein interactions regulate their activity, they can both be considered to be sensitive to the lipid environment. Changes in membrane lipid composition and structure have been described in aged cells and furthermore, these membrane changes have been associated with alterations in GPCR mediated signaling in some of the main health disorders in elderly subjects. Although senescence could be considered a physiologic process, not all aging humans develop the same health disorders. Here, we review the involvement of GPCRs and their lipid environment in the development of the major human pathologies associated with aging such as cancer, neurodegenerative disorders and cardiovascular pathologies.

The influence of long chain polyunsaturate supplementation on docosahexaenoic acid and arachidonic acid in baboon neonate central nervous system

BACKGROUND

Docosahexaenoic acid (DHA) and arachidonic acid (ARA) are major components of the cerebral cortex and visual system, where they play a critical role in neural development. We quantitatively mapped fatty acids in 26 regions of the four-week-old breastfed baboon CNS, and studied the influence of dietary DHA and ARA supplementation and prematurity on CNS DHA and ARA concentrations.

METHODS

Baboons were randomized into a breastfed (B) and four formula-fed groups: term, no DHA/ARA (T-); term, DHA/ARA supplemented (T+); preterm, no DHA/ARA (P-); preterm and DHA/ARA supplemented (P+). At four weeks adjusted age, brains were dissected and total fatty acids analyzed by gas chromatography and mass spectrometry.

RESULTS

DHA and ARA are rich in many more structures than previously reported. They are most concentrated in structures local to the brain stem and diencephalon, particularly the basal ganglia, limbic regions, thalamus and midbrain, and comparatively lower in white matter. Dietary supplementation increased DHA in all structures but had little influence on ARA concentrations. Supplementation restored DHA concentrations to levels of breastfed neonates in all regions except the cerebral cortex and cerebellum. Prematurity per se did not exert a strong influence on DHA or ARA concentrations.

CONCLUSION

1) DHA and ARA are found in high concentration throughout the primate CNS, particularly in gray matter such as basal ganglia; 2) DHA concentrations drop across most CNS structures in neonates consuming formulas with no DHA, but ARA levels are relatively immune to ARA in the diet; 3) supplementation of infant formula is effective at restoring DHA concentration in structures other than the cerebral cortex. These results will be useful as a guide to future investigations of CNS function in the absence of dietary DHA and ARA.

A randomized controlled trial of the effect of fish oil supplementation in late pregnancy and early lactation on the n-3 fatty acid content in human breast milk

The aim of this research was to investigate the effect of fish oil supplementation, in the third trimester of pregnancy and early lactation period of healthy pregnant Danish women. Forty-four pregnant women were randomly allocated to fish oil supplementation (1.3 g EPA and 0.9 g DHA per day) from week 30 of gestation (FO-group) or to a control regimen (olive oil or no oil; controls). The FO-group was randomly subdivided into women stopping fish oil supplementation at delivery IFO(pregn)], and women continuing supplementation for an additional 30 d [FO(pregn/lact)]. Thirty-six women agreed to collect milk samples at days 4, 16, and 30 postpartum. The FA composition of the milk samples was determined by GLC. At days 4, 16, and 30 in lactation, FO(pregn/lact) women (n = 12) had, respectively 2.3 (P = 0.001), 4.1 (P = 0.001), and 3.3 (P = 0.001) times higher mean contents of LCPUFA(n-3) in their breast milk compared with controls (n = 13), and 1.7 (P = 0.005), 2.8 (P = 0.001), and 2.8 (P = 0.001) times higher LCPUFA(n-3) contents, respectively, at these days compared with FO(pregn) women (n = 11). The latter group did not differ significantly from controls with regard to LCPUFA(n-3) content in the breast milk. Similar results were obtained when analyzing separately for effects on the milk content of DHA. Dietary supplementation with 2.7 g LCPUFA(n-3) per day from week 30 of gestation and onward more than tripled the LCPUFA(n-3) content in early breast milk; supplementation limited to pregnancy only was much less effective.

Environmental light and heredity are associated with adaptive changes in retinal DHA levels that affect retinal function

Retinas of rats and mice react to environmental and genetic stimuli by altering the level of DHA in their rod outer segment membranes. We propose that this adaptation is a neuroprotective response to control the number of photons captured by rhodopsin and the efficiency of visual transduction, under conditions where excessive activation of the transduction cascade could lead to cell death.

EFA supplementation in children with inattention, hyperactivity, and other disruptive behaviors

This pilot study evaluated the effects of supplementation with PUFA on blood FA composition and behavior in children with Attention-Deficit/Hyperactivity Disorder (AD/HD)-like symptoms also reporting thirst and skin problems. Fifty children were randomized to treatment groups receiving either a PUFA supplement providing a daily dose of 480 mg DHA, 80 mg EPA, 40 mg arachidonic acid (AA), 96 mg GLA, and 24 mg alpha-tocopheryl acetate, or an olive oil placebo for 4 mon of double-blind parallel treatment. Supplementation with the PUFA led to a substantial increase in the proportions of EPA, DHA, and alpha-tocopherol in the plasma phospholipids and red blood cell (RBC) total lipids, but an increase was noted in the plasma phospholipid proportions of 18:3n-3 with olive oil as well. Significant improvements in multiple outcomes (as rated by parents) were noted in both groups, but a clear benefit from PUFA supplementation for all behaviors characteristic of AD/HD was not observed. For most outcomes, improvement of the PUFA group was consistently nominally better than that of the olive oil group; but the treatment difference was significant, by secondary intent-to-treat analysis, on only 2 out of 16 outcome measures: conduct problems rated by parents (-42.7 vs. -9.9%, n = 47, P = 0.05), and attention symptoms rated by teachers (-14.8 vs. +3.4%, n = 47, P = 0.03). PUFA supplementation led to a greater number of participants showing improvement in oppositional defiant behavior from a clinical to a nonclinical range compared with olive oil supplementation (8 out of 12 vs. 3 out of 11, n = 33, P = 0.02). Also, significant correlations were observed when comparing the magnitude of change between increasing proportions of EPA in the RBC and decreasing disruptive behavior as assessed by the Abbreviated Symptom Questionnaire (ASQ) for parents (r = -0.38, n = 31, P < 0.05), and for EPA and DHA in the RBC and the teachers' Disruptive Behavior Disorders (DBD) Rating Scale for Attention (r = -0.49, n = 24, P < 0.05). Interestingly, significant correlations were observed between the magnitude of increase in alpha-tocopherol concentrations in the RBC and a decrease in scores for all four subscales of the teachers' DBD (Hyperactivity, r = -0.45; Attention, r= -0.60; Conduct, r = -0.41; Oppositional/Defiant Disorder, r = -0.54; n = 24, P < 0.05) as well as the ASQ for teachers (r = -0.51, n = 24, P < 0.05). Thus, the results of this pilot study suggest the need for further research with both n-3 FA and vitamin E in children with behavioral disorders.

Docosahexaenoic acid in the diet: its importance in maintenance and restoration of neural membrane function

The central nervous system has the second highest concentration of lipids after adipose tissue. Long chain fatty acids, particularly arachidonic acid and docosahexaenoic acid, are integral components of neural membrane phospholipids. Alterations in neural membrane phospholipid components cannot only influence crucial intracellular and intercellular signaling but also alter many membrane physical properties such as fluidity, phase transition temperature, bilayer thickness, and lateral domains. A deficiency of docosahexaenoic acid markedly affects neurotransmission, membrane-bound enzyme and ion channel activities, gene expression, intensity of inflammation, and immunity and synaptic plasticity. Docosahexaenoic acid deficiency is associated with normal aging, Alzheimer disease, hyperactivity, schizophrenia, and peroxisomal disorders. Although the molecular mechanism of docosahexaenoic acid involvement in the disorders remains unknown, the supplementation of docosahexaenoic acid in the diet restores gene expression and modulates neurotransmission. Also, improvements are seen in signal transduction processes associated with behavioral deficits, learning activity, peroxisomal disorders, and psychotic changes in schizophrenia, depression, hyperactivity, stroke, and Alzheimer disease.

An investigation into the role of calcium in the modulation of rat synaptosomal D-[3H]aspartate transport by docosahexaenoic acid

The effect of the polyunsaturated fatty acid cis-4,7,10,13,16,19-docosahexaenoic acid (DHA) on the high-affinity, sodium-dependent uptake of D-[3H]aspartate into purified rat brain synaptosomes was examined. Incubation of the synaptosomes with 20 microM DHA caused over 50% inhibition of the maximum velocity (V(max)) of D-[3H]aspartate transport. This inhibition was significantly potentiated by pre-exposure of the synaptosomes to the fatty acid for 10 min prior to the start of the transport assay. Less highly unsaturated fatty acids such as arachidonic acid (cis-5,8,11,14-eicosatetraenoic acid), linolenic acid (cis-9,12,15-octadecatrienoic acid) and oleic acid (cis-9-octadecenoic acid) were significantly less potent than DHA. Removal of extracellular calcium, or reduction of the intracellular calcium concentration using the intracellular calcium chelator BAPTA/AM (10 microM), did not reduce the inhibition caused by DHA. On the other hand, an increase in the concentration of intracellular calcium mediated by thapsigargin (25 microM) or the calcium ionophore A23187 (10 or 100 nM) led to a reduction in the rate of D-[3H]aspartate transport in the absence of DHA. The CaM kinase II inhibitor, KN-93, reduced D-[3H]aspartate uptake independently of whether DHA was also present, but had no effect on the inhibition of D-[3H]aspartate uptake by either A23187 or thapsigargin. We conclude that whereas DHA inhibits synaptosomal D-[3H]aspartate uptake in a calcium-independent manner, a calcium-based mechanism exists that can also modulate glutamate transporter activity.

Low serum cholesteryl ester-docosahexaenoic acid levels in Alzheimer's disease: a case-control study

Low n-3 polyunsaturated fatty acid (PUFA) status may be associated with neuro-degenerative disorders, in particular Alzheimer's disease, which has been associated with poor dietary fish or n-3 PUFA intake, and low docosahexaenoic acid (DHA) status. The present case-control study used an established biomarker of n-3 PUFA intake (serum cholesteryl ester-fatty acid composition) to determine n-3 PUFA status in patients with Alzheimer's disease, who were free-living in the community. All cases fulfilled the National Institute of Neurological and Communicative Disorders and Stroke and Alzheimer's Disease and Related Disorders Association criteria for Alzheimer's disease. Detailed neuropsychological testing and neuroimaging established the diagnosis in all cases. The subjects (119 females and twenty-nine males) aged 76.5 (SD 6.6) years had a clinical dementia rating (CDR) of 1 (SD 0.62) and a mini mental state examination (MMSE) score of 19.5 (SD 4.8). The control subjects (thirty-six females and nine males) aged 70 (SD 6.0) years were not cognitively impaired (defined as MMSE score <24): they had a mean MMSE score of 28.9 (SD 1.1). Serum cholesteryl ester-eicosapentaenoic acid and DHA levels were significantly lower (P<0.05 and P<0.001 respectively) in all MMSE score quartiles of patients with Alzheimer's disease compared with control values. Serum cholesteryl ester-DHA levels were progressively reduced with severity of clinical dementia. DHA levels did not differ in patients with Alzheimer's disease across age quartiles: all were consistently lower than in control subjects. Step-wise multiple regression analysis showed that cholesteryl ester-DHA and total saturated fatty acid levels were the important determinants of MMSE score and CDR. It remains to be determined whether low DHA status in Alzheimer's disease is a casual factor in the pathogenesis and progression of Alzheimer's disease.

Effects of human milk fortification on morbidity factors in very low birth weight infants

BACKGROUND

The use of human milk as a sole source of nutrients for preterm infants has been the subject of debate in recent years. We studied the morbidity factors associated with hospitalization of very low birth weight (VLBW) infants fed human milk with and without fortification.

PATIENTS AND METHODS

One hundred VLBW infants were randomly assigned to two groups with stratification for gestation and weight. The control group (n-50; mean birth weight 1239+/-186 g and mean gestation 29.3+/-2.1 wks) was fed human milk only, and in the fortifier group (n=50; mean birth weight 1245+/-191 g and mean gestation 29.5+/-2.1 wks), human milk was enriched with a fortifier after the babies reached a volume of 140 mL/kg/day by the enteral route. Weight was measured twice weekly, biochemical indices of nutritional and bone status and serum electrolytes were obtained weekly, and clinical evidence for sepsis, necrotizing enterocolitis and feeding intolerance was assessed regularly until infants were discharged.

RESULTS

Hospital stay was less than 45 days in the majority (94%) of the babies in the fortifier group, whereas the majority (66%) of the babies in the control group stayed for more than 45 days (P<0.01). Low serum phosphorus and raised alkaline phosphate levels were seen more frequently in the control group without fortification (p<0.01), as weel as hyponatremia (P<0.01), late metabolic acidosis of prematurity (P<0.01) and culture-proven sepsis (p<0.05). There was no significant difference in the occurrence of necrotizing enterocolitis between the two groups (P>0.05).

CONCLUSION

Human milk fortification has beneficial effects on the growth of VLBW infants and decreases hospital stay and morbidity associated with prematurity and very low birth weight, with economic and psychological benefits for the parents.

Lipid metabolism in pregnancy and its consequences in the fetus and newborn

During early pregnancy there is an increase in body fat accumulation, associated with both hyperphagia and increased lipogenesis. During late pregnancy there is an accelerated breakdown of fat depots, which plays a key role in fetal development. Besides using placental transferred fatty acids, the fetus benefits from two other products: glycerol and ketone bodies. Although glycerol crosses the placenta in small proportions, it is a preferential substrate for maternal gluconeogenesis, and maternal glucose is quantitatively the main substrate crossing the placenta. Enhanced ketogenesis under fasting conditions and the easy transfer of ketones to the fetus allow maternal ketone bodies to reach the fetus, where they can be used as fuels for oxidative metabolism as well as lipogenic substrates. Although maternal cholesterol is an important source of cholesterol for the fetus during early gestation, its importance becomes minimal during late pregnancy, owing to the high capacity of fetal tissues to synthesize cholesterol. Maternal hypertriglyceridemia is a characteristic feature during pregnancy and corresponds to an accumulation of triglycerides not only in very low-density lipoprotein but also in low- and high-density lipoprotein. Although triglycerides do not cross the placental barrier, the presence of lipoprotein receptors in the placenta, together with lipoprotein lipase, phospholipase A2, and intracellular lipase activities, allows the release to the fetus of polyunsaturated fatty acids transported as triglycerides in maternal plasma lipoproteins. Normal fetal development needs the availability of both essential fatty acids and long chain polyunsaturated fatty acids, and the nutritional status of the mother during gestation has been related to fetal growth. However, excessive intake of certain long chain fatty acids may cause both declines in arachidonic acid and enhanced lipid peroxidation, reducing antioxidant capacity.

Implications of dietary fatty acids during pregnancy on placental, fetal and postnatal development--a review

During pregnancy, the mother adapts her metabolism to support the continuous draining of substrates by the fetus. Her increase in net body weight (free of the conceptus) corresponds to the accumulation of fat depots during the first two-thirds of gestation, switching to an accelerated breakdown of these during the last trimester. Under fasting conditions, adipose tissue lipolytic activity is highly enhanced, and its products, free fatty acids (FFA) and glycerol, are mainly driven to maternal liver, where FFA are converted to ketone bodies and glycerol to glucose, which easily cross the placenta and sustain fetal metabolism. Lipolytic products reaching maternal liver are also used for triglyceride synthesis that are released in turn to the circulation, where together with an enhanced transfer of triglycerides among the different lipoprotein fractions, and a decrease in extrahepatic lipoprotein lipase activity, increase the content of triglycerides in all the lipoprotein fractions. Long chain polyunsaturated fatty acids (LCPUFA) circulate in maternal plasma associated to lipoprotein triglycerides, and in a minor proportion in the form of FFA. Despite the lack of a direct placental transfer of triglycerides, diffusion of their fatty acids to the fetus is ensured by means of lipoprotein receptors, lipoprotein lipase activity and intracellular lipase activities in the placenta. Maternal plasma FFA are also an important source of LCPUFA to the fetus, and their placental uptake occurs via a selective process of facilitated membrane translocation involving a plasma membrane fatty acid-binding protein. This mechanism together with a selective cellular metabolism determine the actual rate of placental transfer and its selectivity, resulting even in an enrichment of certain LCPUFA in fetal circulation as compared to maternal. The degree to which the fetus is capable of fatty acid desaturation and elongation is not clear, although both term and preterm infants can synthesize LCPUFA from parental essential fatty acids. Nutritional status of the mother during gestation is related to fetal growth, and excessive dietary intake of certain LCPUFA has inhibitory effects on Delta-5- and Delta-6-desaturases. This inhibition causes major declines in arachidonic acid levels, as directly found in pregnant and lactating rats fed a fish oil-rich diet as compared to olive oil. An excess in dietary PUFA may also enhance peroxidation and reduce antioxidant capacity. Thus, since benefit to risks of modifying maternal fat intake in pregnancy and lactation are not yet completely established, additional studies are needed before recommendations to increase LCPUFA intake in pregnancy are made.