Effects of n-3 long chain polyunsaturated fatty acid supplementation on visual and cognitive development throughout childhood: a review of human studies

Omega-3 fatty acids and health of auditory and vestibular systems: a comprehensive review

PURPOSE

The purpose of this study was to comprehensively review animal and human studies that explore the role of omega-3 PUFAs in maintaining the health of the auditory organ across all life stages.

METHODS

This narrative review involved searching Scopus, PubMed, Google Scholar, and Cochrane Library databases for relevant articles from December 1980 to July 2023.

RESULTS

some animal and human studies suggest that both deficiency and excessive intake of long-chain omega-3 PUFAs, particularly docosahexaenoic acid (DHA), can lead to auditory neural conduction impairment and reduced hearing acuity from fetal development to old age (presbycusis). These effects are likely to be dependent on the dosage. Some research indicates that an excessive intake of omega-3, rather than a deficiency, can result in nutritional toxicity and hearing impairments. Animal studies highlight the positive impact of omega-3 supplements with high DHA content in addressing hearing damage, but human research on this subject is limited. Furthermore, certain studies propose that omega-3 PUFAs may prevent or delay age-related hearing loss, with high plasma omega-3 concentration, particularly long-chain omega-3 PUFA, linked to reduced hearing loss. Additionally, consuming fish more than twice a week may be associated with a lower risk of hearing loss in adulthood, with these effects potentially influenced by age and gender. However, the majority of studies have been conducted on animals, and clinical trials are scarce. Research on the influence of omega-3 PUFAs on the peripheral and central vestibular systems remains limited.

CONCLUSION

This article delves into the impact of omega-3 on the auditory-vestibular system, exploring its influence on neurodevelopment, protection, and treatment. It not only highlights specific research gaps but also offers valuable insights for potential future studies.

Maternal choline supplementation protects against age-associated cholinergic and GABAergic basal forebrain neuron degeneration in the Ts65Dn mouse model of Down syndrome and Alzheimer's disease

Down syndrome (DS) is a genetic disorder caused by triplication of human chromosome 21. In addition to intellectual disability, DS is defined by a premature aging phenotype and Alzheimer's disease (AD) neuropathology, including septohippocampal circuit vulnerability and degeneration of basal forebrain cholinergic neurons (BFCNs). The Ts65Dn mouse model recapitulates key aspects of DS/AD pathology, namely age-associated atrophy of BFCNs and cognitive decline in septohippocampal-dependent behavioral tasks. We investigated whether maternal choline supplementation (MCS), a well-tolerated treatment modality, protects vulnerable BFCNs from age- and genotype-associated degeneration in trisomic offspring. We also examined the effect of trisomy, and MCS, on GABAergic basal forebrain parvalbumin neurons (BFPNs), an unexplored neuronal population in this DS model. Unbiased stereological analyses of choline acetyltransferase (ChAT)-immunoreactive BFCNs and parvalbumin-immunoreactive BFPNs were conducted using confocal z-stacks of the medial septal nucleus and the vertical limb of the diagonal band (MSN/VDB) in Ts65Dn mice and disomic (2N) littermates at 3-4 and 10-12 months of age. MCS trisomic offspring displayed significant increases in ChAT-immunoreactive neuron number and density compared to unsupplemented counterparts, as well as increases in the area of the MSN/VDB occupied by ChAT-immunoreactive neuropil. MCS also rescued BFPN number and density in Ts65Dn offspring, a novel rescue of a non-cholinergic cell population. Furthermore, MCS prevented age-associated loss of BFCNs and MSN/VDB regional area in 2N offspring, indicating genotype-independent neuroprotective benefits. These findings demonstrate MCS provides neuroprotection of vulnerable BFCNs and non-cholinergic septohippocampal BFPNs, indicating this modality has translational value as an early life therapy for DS, as well as extending benefits to the aging population at large.

Antarctic krill (Euphausia superba) oil high internal phase emulsions improved the lipid quality and gel properties of surimi gel

In the study, high internal phase emulsions (HIPEs) prepared from Antarctic krill oil (AKO) were added into surimi and the effects on gel properties, lipid quality and stability were investigated. It is found that HIPEs-added groups exhibited higher gel strength and lower cooking loss than Oil-added counterparts. HIPEs-added groups had higher proportion of capillary water, and microstructure of HIPEs-added gels showed fewer large voids and small size droplets. HIPEs-added groups also showed less pronounced myosin heavy chain band. HIPEs- and Oil-added gels showed > 3500 mg/kg EPA + DHA and 0.4-0.8 mg/kg astaxanthin, and most HIPEs-added groups had higher levels of them but lower TBARS values. Results suggest AKO-HIPEs could reduce the intervention by lipids on myosin crosslinking during gelation, and protect fatty acids and asxtanthin from oxidation due to oxygen-isolation led by their high accumulation. Thus, AKO-HIPEs can be applied to fortify ω-3 PUFA and maintain good gel properties in surimi product.

Raman spectroscopy and NIR hyperspectral imaging for in-line estimation of fatty acid features in salmon fillets

Raman spectroscopy was compared with near infrared (NIR) hyperspectral imaging for determination of fat composition (%EPA + DHA) in salmon fillets at short exposure times. Fillets were measured in movement for both methods. Salmon were acquired from several different farming locations in Norway with different feeding regimes, representing a realistic variation of salmon in the market. For Raman, we investigated three manual scanning strategies; i) line scan of loin, ii) line scan of belly and iii) sinusoidal scan of belly at exposure times of 2s and 4s. NIR images were acquired while the fillets moved on a conveyor belt at 40 cm/s, which corresponds to an acquisition time of 1s for a 40 cm long fillet. For NIR images, three different regions of interest (ROI) were investigated including the i) whole fillet, ii) belly segment, and iii) loin segment. For both Raman and NIR measurements, we investigated an untrimmed and trimmed version of the fillets, both relevant for industrial in-line evaluation. For the trimmed fillets, a fat rich deposition layer in the belly was removed. The %EPA + DHA models were validated by cross validation (N = 51) and using an independent test set (N = 20) which was acquired in a different season. Both Raman and NIR showed promising results and high performances in the cross validation, with R2_CV = 0.96 for Raman at 2s exposure and R2_CV = 0.97 for NIR. High performances were obtained also for the test set, but while Raman had low and stable biases for the test set, the biases were high and varied for the NIR measurements. Analysis of variance on the squared test set residuals showed that performance for Raman measurements were significantly higher than NIR at 1% significance level (p = 0.000013) when slope-and-bias errors were not corrected, but not significant when residuals were slope-and-bias corrected (p = 0.28). This indicated that NIR was more sensitive to matrix effects. For Raman, signal-to-noise ratio was the main limitation and there were indications that Raman was close to a critical sample exposure time at the 2s signal accumulation.

Associations between Dietary Intake, Blood Levels of Omega-3 and Omega-6 Fatty Acids and Reading Abilities in Children

Lower levels of omega-3 polyunsaturated fatty acids (PUFAs) have been described in individuals with reading difficulties, but the degree and the nature of such deficiencies as well as the role of nutrition are a matter of debate. The aim of the present study was to investigate the associations between PUFA blood levels, nutritional status, and reading/writing/phonological awareness performances in 42 school-age children with varying levels of reading ability. Significant correlations were found between PUFA levels (specific omega-6/omega-3 ratios), the ratio of omega-6-derived calories to the total amount of calories and reading scores. Mediation analysis showed a mediating effect of fatty acids on the association between reading speed scores and nutritional status. Moderation analysis, moreover, showed that the associations of omega-6/omega-3 ratios in the blood and Kcal omega-6/Kcal total in dietary intake were moderated by reading speed performances. Results of the mediation and moderation models confirm that the associations of dietary intake with PUFA levels in the blood vary depending on learning abilities. Reading skills appear to be sensitive to the effects of a complex set of favorable conditions related to the presence of higher omega-3 blood levels. These conditions may reflect the action of dietary as well as genetic and epigenetic mechanisms.

Nutritional value of the marine fish in Bangladesh and their potential to address malnutrition: A review

Marine fish are good source of essential macro- and micronutrients and major food items in coastal areas in Bangladesh. However, there is no review that details the nutritional value of marine fish in Bangladesh. Therefore, this review focuses on the nutrient composition of marine fish in Bangladesh and how the marine fish can address common nutrient deficiencies among women and children. Nutrient composition data was collected through literature searching in databases and source, including PubMed, Web of Science, Google Scholar, ScienceDirect, WorldFish, and Bangladesh-based database Banglajol. Calculation was carried out to present how one serving marine fish could potentially meet the daily requirement of protein, iron, zinc, calcium, vitamin A, and docosahexaenoic acid (DHA) for pregnant and lactating women and children aged 6-23 months. A total of 97 entries covering nutrient composition analysis of 67 individual fish species were extracted from 12 articles published between 1993 and 2020. Included articles contained analysis of proximate composition, vitamins, minerals, fatty acids, and amino acid. Twelve minerals and nine vitamins were analyzed and reported. The average energy, protein, fat, and ash content per 100 g edible raw marine fish was 343.58 kJ, 16.76 g, 4.16 g, and 2.22 g, respectively. According to available data, marine fish are good sources of protein, zinc, calcium, and DHA. Pelagic small fish, which are mainly captured by artisanal small-scale fishers, had more nutritional value than other categories of fish. Furthermore, marine small fish were found more nutritious than commonly consumed freshwater fish types in Bangladesh, including major carps, introduced carps, and tilapia. Therefore, the study concludes that marine fish have high potential to address malnutrition in Bangladesh. There was scarcity of literature regarding the nutrient composition of marine fish in Bangladesh and in South Asia as a whole, so more comprehensive quality research in this area is recommended.

Regulation of Δ6Fads2 Gene Involved in LC-PUFA Biosynthesis Subjected to Fatty Acid in Large Yellow Croaker (Larimichthys crocea) and Rainbow Trout (Oncorhynchus mykiss)

Δ6 fatty acyl desaturase (Δ6Fads2) is regarded as the first rate-limiting desaturase that catalyzes the biosynthesis of long-chain polyunsaturated fatty acids (LC-PUFA) from 18-carbon fatty acid in vertebrates, but the underlying regulatory mechanism of fads2 has not been comprehensively understood. This study aimed to investigate the regulation role of fads2 subjected to fatty acid in large yellow croaker and rainbow trout. In vivo, large yellow croaker and rainbow trout were fed a fish oil (FO) diet, a soybean oil (SO) diet or a linseed oil (LO) diet for 10 weeks. The results show that LO and SO can significantly increase fads2 expression (p < 0.05). In vitro experiments were conducted in HEK293T cells or primary hepatocytes to determine the transcriptional regulation of fads2. The results show that CCAAT/enhancer-binding protein α (C/EBPα) can up-regulate fads2 expression. GATA binding protein 3 (GATA3) can up-regulate fads2 expression in rainbow trout but showed opposite effect in large yellow croaker. Furthermore, C/EBPα protein levels were significantly increased by LO and SO (p < 0.05), gata3 expression was increased in rainbow trout by LO but decreased in large yellow croaker by LO and SO. In conclusion, we revealed that FO replaced by LO and SO increased fads2 expression through a C/EBPα and GATA3 dependent mechanism in large yellow croaker and rainbow trout. This study might provide critical insights into the regulatory mechanisms of fads2 expression and LC-PUFA biosynthesis.

Small-Quantity Lipid-Based Nutrient Supplements Increase Infants' Plasma Essential Fatty Acid Levels in Ghana and Malawi: A Secondary Outcome Analysis of the iLiNS-DYAD Randomized Trials

INTRODUCTION

Small-quantity (SQ) lipid-based nutrient supplements (LNSs) may influence infants' plasma fatty acid (FA) profiles, which could be associated with short- and long-term outcomes.

OBJECTIVES

We aimed to determine the impact of SQ-LNS consumption on infants' plasma FA profiles in Ghana and Malawi.

METHODS

Ghanaian (n = 1320) and Malawian (n = 1391) women ≤20 weeks pregnant were assigned to consume 60 mg iron and 400 μg folic acid daily until delivery [iron and folic acid (IFA) group], multiple-micronutrient supplements (MMNs) until 6 months postpartum (MMN group), or SQ-LNSs (∼7.8 linoleic acid:α-linolenic acid ratio) until 6 months postpartum (LNS group). LNS group infants received SQ-LNS from 6 to 18 months of age. We compared infant plasma FAs by intervention group in subsamples (n = 379 in Ghana; n = 442 in Malawi) at 6 and 18 months using ANOVA and Poisson regression models. Main outcomes were mean percentage compositions (%Cs; percentage of FAs by weight) of α-linolenic acid (ALA), linoleic acid (LA), EPA, DHA, and arachidonic acid (AA).

RESULTS

At 6 months, LNS infants had greater mean ± SD ALA %Cs in Ghana (0.23 ± 0.08; IFA, 0.21 ± 0.06; MMN, 0.21 ± 0.07; P = 0.034) and Malawi (0.42 ± 0.16; IFA, 0.38 ± 0.15; MMN, 0.38 ± 0.14; P = 0.034) and greater AA values in Ghana (6.25 ± 1.24; IFA, 6.12 ± 1.13; MMN, 5.89 ± 1.24; P = 0.049). At 18 months, LNS infants had a tendency towards greater ALA (0.32 ± 0.16; IFA, 0.24 ± 0.08; MMN, 0.24 ± 0.10; P = 0.06) and LA (27.8 ± 3.6; IFA, 26.9 ± 2.9; MMN, 27.0 ± 3.1; P = 0.06) in Ghana, and greater ALA (0.45 ± 0.18; IFA, 0.39 ± 0.18; MMN, 0.39 ± 0.18; P < 0.001) and LA (29.7 ± 3.5; IFA, 28.7 ± 3.3; MMN, 28.6 ± 3.4; P = 0.011) in Malawi. The prevalence of ALA below the population-specific 10th percentile was lower in the LNS group compared to the MMN group, but not the IFA group. Groups did not differ significantly in plasma EPA or DHA levels.

CONCLUSIONS

SQ-LNS increased infants' plasma essential FA levels in Ghana and Malawi, which may have implications for health and developmental outcomes. These trials were registered at clinicaltrials.gov as NCT00970866 and NCT01239693.

A Mixed-Lipid Emulsion Containing Fish Oil for the Parenteral Nutrition of Preterm Infants: No Impact on Visual Neuronal Conduction

Fish oil is rich in omega-3 fatty acids and essential for neuronal myelination and maturation. The aim of this study was to investigate whether the use of a mixed-lipid emulsion composed of soybean oil, medium-chain triglycerides, olive oil, and fish oil (SMOF-LE) compared to a pure soybean oil-based lipid emulsion (S-LE) for parenteral nutrition had an impact on neuronal conduction in preterm infants. This study is a retrospective matched cohort study comparing preterm infants <1000 g who received SMOF-LE in comparison to S-LE for parenteral nutrition. Visual evoked potentials (VEPs) were assessed longitudinally from birth until discharge. The latencies of the evoked peaks N2 and P2 were analyzed. The analysis included 76 infants (SMOF-LE: n = 41 and S-LE: n = 35) with 344 VEP measurements (SMOF-LE: n= 191 and S-LE n = 153). Values of N2 and P2 were not significantly different between the SMOF-LE and S-LE groups. A possible better treatment effect in the SMOF-LE group was seen as a trend toward a shorter latency, indicating faster neural conduction at around term-equivalent age. Prospective trials and follow-up studies are necessary in order to evaluate the potential positive effect of SMOF-LE on neuronal conduction and visual pathway maturation.

Maternal Supply of Both Arachidonic and Docosahexaenoic Acids Is Required for Optimal Neurodevelopment

During the last trimester of gestation and for the first 18 months after birth, both docosahexaenoic acid,22:6n-3 (DHA) and arachidonic acid,20:4n-6 (ARA) are preferentially deposited within the cerebral cortex at a rapid rate. Although the structural and functional roles of DHA in brain development are well investigated, similar roles of ARA are not well documented. The mode of action of these two fatty acids and their derivatives at different structural-functional roles and their levels in the gene expression and signaling pathways of the brain have been continuously emanating. In addition to DHA, the importance of ARA has been much discussed in recent years for fetal and postnatal brain development and the maternal supply of ARA and DHA. These fatty acids are also involved in various brain developmental processes; however, their mechanistic cross talks are not clearly known yet. This review describes the importance of ARA, in addition to DHA, in supporting the optimal brain development and growth and functional roles in the brain.

Maternal Docosahexaenoic Acid Status during Pregnancy and Its Impact on Infant Neurodevelopment

Dietary components are essential for the structural and functional development of the brain. Among these, docosahexaenoic acid, 22:6n-3 (DHA), is critically necessary for the structure and development of the growing fetal brain in utero. DHA is the major n-3 long-chain polyunsaturated fatty acid in brain gray matter representing about 15% of all fatty acids in the human frontal cortex. DHA affects neurogenesis, neurotransmitter, synaptic plasticity and transmission, and signal transduction in the brain. Data from human and animal studies suggest that adequate levels of DHA in neural membranes are required for maturation of cortical astrocyte, neurovascular coupling, and glucose uptake and metabolism. Besides, some metabolites of DHA protect from oxidative tissue injury and stress in the brain. A low DHA level in the brain results in behavioral changes and is associated with learning difficulties and dementia. In humans, the third trimester-placental supply of maternal DHA to the growing fetus is critically important as the growing brain obligatory requires DHA during this window period. Besides, DHA is also involved in the early placentation process, essential for placental development. This underscores the importance of maternal intake of DHA for the structural and functional development of the brain. This review describes DHA’s multiple roles during gestation, lactation, and the consequences of its lower intake during pregnancy and postnatally on the 2019 brain development and function.

Effect of Omega-3 Long Chain Polyunsaturated Fatty Acids (n-3 LCPUFA) Supplementation on Cognition in Children and Adolescents: A Systematic Literature Review with a Focus on n-3 LCPUFA Blood Values and Dose of DHA and EPA

Omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA) supplementation in the cardiovascular field is effective if a certain Omega-3 index (O3I) is achieved or the daily n-3 LCPUFA dose is high enough. Whether this applies to studies on cognition in children and adolescents is unclear. The aims of the current review were to investigate whether: (1) a certain O3I level and (2) a minimum daily n-3 LCPUFA dose are required to improve cognition in 4-25 year olds. Web of Science and PubMed were searched. Inclusion criteria: placebo controlled randomized controlled trial; participants 4-25 years; supplementation with docosahexaenoic acid (DHA) and/or eicosapentaenoic acid (EPA); assessing cognition; in English and ≥10 participants per treatment arm. Thirty-three studies were included, 21 in typically developing participants, 12 in those with a disorder. A positive effect on cognitive measures was more likely in studies with an increase in O3I to >6%. Half of the studies in typically developing children with daily supplementation dose ≥450 mg DHA + EPA showed improved cognition. For children with a disorder no cut-off value was found. In conclusion, daily supplementation of ≥450 mg DHA + EPA per day and an increase in the O3I to >6% makes it more likely to show efficacy on cognition in children and adolescents.

Fatty Acid Reference Intervals in Red Blood Cells among Pregnant Women in Norway-Cross Sectional Data from the 'Little in Norway' Cohort

There is a growing interest in determining fatty acid reference intervals from pregnancy cohort, especially considering the lack of reference values for pregnant women in the literature and the generalized misconception of equating reference intervals for nonpregnant women as equivalent to pregnant women. Seafood and supplements are important dietary sources for the omega-3 long-chain polyunsaturated fatty acids (ω-3 LCPUFA), such as eicosapentaenoic acid (EPA, 20:5ω-3), docosapentaenoic acid (DPA, 22:55ω-3), and docosahexaenoic acid (DHA, 22:6ω-3). Sufficient intake of EPA and DHA is vital during pregnancy for the development of the fetus, as well as for maintaining adequate levels for the mother. This study describes the fatty acid status and suggests reference values and cut-offs for fatty acids in red blood cells (RBC) from pregnant women (n = 247). An electronic food frequency questionnaire (e-FFQ) mapped the dietary habits of the participants, and gas chromatography was used to determine the fatty acid levels in RBC. The association between e-FFQ variables and fatty acid concentrations was established using a principal component analysis (PCA). Twenty-nine-point-one percent (29.1%) of the participants reported eating seafood as dinner according to the Norwegian recommendations, and they added in their diet as well a high percentage (76.9%) intake of ω-3 supplements. The concentration levels of fatty acids in RBC were in agreement with those reported in similar populations from different countries. The reference interval 2.5/97.5 percentiles for EPA, DPA, DHA were 0.23/2.12, 0.56/2.80, 3.76/10.12 in relative concentration units (%), and 5.99/51.25, 11.08/61.97, 64.25/218.08 in absolute concentration units (µg/g), respectively. The number of participants and their selection from all over Norway vouch for the representativeness of the study and the validity of the proposed reference values, and therefore, the study may be a useful tool when studying associations between fatty acid status and health outcome in future studies. To the best of our knowledge, this is the first PCA study reporting a direct association between ω-3 LCPUFA and intake of seafood and ω-3 supplements in a pregnancy cohort.

Exclusive Breastfeeding Predicts Higher Hearing-Language Development in Girls of Preschool Age

Cognitive disorders are increasing in prevalence. Nutritional or metabolic stressors during early life, and female sex, are predisposing conditions towards the development of cognitive diseases, including Alzheimer’s disease. Though there is evidence that breastfeeding may play a beneficial role in children’s neurocognitive development, the literature remains controversial. In this study we aimed at assessing the association between exclusive breastfeeding and children’s cognitive development from six months to five years of age, addressing sex differences. In 80 mother-child pairs from the Pisa birth cohort (PISAC), we measured cognitive development in groups of children of 6, 12, 18, 24, 36, and 60 months by Griffiths Mental Development Scales, parents’ intelligence quotient (IQ) by Raven’s progressive matrices, and maternal and infants’ anthropometric parameters. We found that exclusive breastfeeding was associated with higher hearing-language development in five years old girls, independent of maternal IQ, age and BMI (body mass index). Exclusive breastfeeding in the first three months of life seemed sufficient to establish this positive relationship. In conclusion, our data indicate that exclusive breastfeeding is a positive predictor of cognitive development in preschool-age girls, paving the way for the implementation of sex-specific cognitive disease risk detection and prevention strategies from early life. Further studies are warranted to explore causality and longer term effects.

Dietary diversity and food intake of urban preschool children in North-Western Sri Lanka

Childhood malnutrition, associated with poor diet, is a clear public health threat in Sri Lanka, with high rates of under‐nutrition and micronutrient deficiencies coupled with the growing risk of overweight/obesity in urban locations. This study explored the dietary diversity and food intake of urban living Sri Lankan preschool children. A cross‐sectional analysis of the baseline data from a cohort study was conducted with parents/caregivers of children aged 2–6 years, from 21 preschool centres in Kurunegala District, Sri Lanka. Demographic and socio‐economic factors, dietary diversity score (DDS) (n = 597) and food intake (n = 458) (using a food frequency questionnaire) were assessed. Children had a mean DDS of 4.56 ± 0·85 out of 9, with most (91.1%) in the medium DDS category (DDS of 3.1–6.0), consuming rice as most common food. Lentils were consumed more than any meat or alternative food groups at all DDS levels. Child DDS differs with parent/caregiver age and ethnicity. Mean daily intakes of fruit (1.02) and vegetables (0.84) servings align with approximately half of national recommendations, with less than 20% of children meeting daily recommendations. More than one‐third consumed sugary snacks and confectionaries daily and 1 in 10 had them twice a day. Around 40% reported watching television while eating the evening meal. Despite the majority having reasonable DDSs (medium category), findings highlighted inadequate intakes of fruits and vegetables, excessive intakes of sugary snacks and unhealthy dietary and social behaviours, suggests the need for population‐based interventions to promote healthier dietary habits.

The Furan Fatty Acid 9M5 Acts as a Partial Ligand to Peroxisome Proliferator-Activated Receptor gamma and Enhances Adipogenesis in 3T3-L1 Preadipocytes

A food that has been praised for its beneficial effects on overall health is fish, particularly its polyunsaturated n-3 fatty acids, including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). However, it has recently been suggested that minor fatty acids such as furan fatty acids are needed in combination with DHA and EPA to exert these positive effects of fish and fish oils. Only recently have furan fatty acids become available in quantities that allow the investigation of their biofunctional properties. In this study, the uptake and effect of the furan fatty acid 9-(3-methyl-5-pentylfuran-2-yl)-nonanoic acid (9M5) as a sole component and in combination with DHA and EPA on adipogenesis were analyzed using the 3T3-L1 cell model. 9M5 is taken up and metabolized into 7M5, 5M5, and 3M5 in 3T3-L1 adipocytes during a 24-h period as shown with gas chromatography with mass spectrometry (GC/MS). Furthermore, 9M5 significantly increased lipid accumulation during the differentiation process of 3T3-L1 preadipocytes into adipocytes. In addition, the combinations of DHA + 9M5 and EPA + DHA + 9M5 also exerted a significant increase compared to control adipocytes. 3T3-L1 cells incubated with 9M5 resulted in an increased protein expression of PPARγ, C/EBPα, FABP4, and adiponectin, although not to the extent that DHA as a sole component or DHA + 9M5 did. Earlier studies have shown that DHA is a natural ligand for PPARγ, thus being a potential alternative to the antidiabetic thiazolidinediones. We show that 9M5 activates a PPARγ-responsive reporter gene and could therefore be a natural ligand for PPARγ.

CRISPR/Cas9-mediated editing of Δ5 and Δ6 desaturases impairs Δ8-desaturation and docosahexaenoic acid synthesis in Atlantic salmon (Salmo salar L.)

The in vivo functions of Atlantic salmon fatty acyl desaturases (fads2), Δ6fads2-a, Δ6fads2-b, Δ6fads2-c and Δ5fads2 in long chain polyunsaturated fatty acid (LC-PUFA) synthesis in salmon and fish in general remains to be elucidated. Here, we investigate in vivo functions and in vivo functional redundancy of salmon fads2 using two CRISPR-mediated partial knockout salmon, Δ6abc/5^Mt with mutations in Δ6fads2-a, Δ6fads2-b, Δ6fads2-c and Δ5fads2, and Δ6bc^Mt with mutations in Δ6fads2-b and Δ6fads2-c. F0 fish displaying high degree of gene editing (50–100%) were fed low LC-PUFA and high LC-PUFA diets, the former containing reduced levels of eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) acids but higher content of linoleic (18:2n-6) and alpha-linolenic (18:3n-3) acids, and the latter containing high levels of 20:5n-3 and 22:6n-3 but reduced compositions of 18:2n-6 and 18:3n-3. The Δ6abc/5^Mt showed reduced 22:6n-3 levels and accumulated Δ6-desaturation substrates (18:2n-6, 18:3n-3) and Δ5-desaturation substrate (20:4n-3), demonstrating impaired 22:6n-3 synthesis compared to wildtypes (WT). Δ6bc^Mt showed no effect on Δ6-desaturation compared to WT, suggesting Δ6 Fads2-a as having the predominant Δ6-desaturation activity in salmon, at least in the tissues analyzed. Both Δ6abc/5^Mt and Δ6bc^Mt demonstrated significant accumulation of Δ8-desaturation substrates (20:2n-6, 20:3n-3) when fed low LC-PUFA diet. Additionally, Δ6abc/5^Mt demonstrated significant upregulation of the lipogenic transcription regulator, sterol regulatory element binding protein-1 (srebp-1) in liver and pyloric caeca under reduced dietary LC-PUFA. Our data suggest a combined effect of endogenous LC-PUFA synthesis and dietary LC-PUFA levels on srebp-1 expression which ultimately affects LC-PUFA synthesis in salmon. Our data also suggest Δ8-desaturation activities for salmon Δ6 Fads2 enzymes.

Dietary Fish Oil Alters DNA Methylation of Genes Involved in Polyunsaturated Fatty Acid Biosynthesis in Muscle and Liver of Atlantic Salmon (Salmo salar)

Adequate dietary supply of eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3) is required to maintain health and growth of Atlantic salmon (Salmo salar). However, salmon can also convert α-linolenic acid (18:3n-3) into eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3) by sequential desaturation and elongation reactions, which can be modified by 20:5n-3 and 22:6n-3 intake. In mammals, dietary 20:5n-3 + 22:6n-3 intake can modify Fads2 expression (Δ6 desaturase) via altered DNA methylation of its promoter. Decreasing dietary fish oil (FO) has been shown to increase Δ5fad expression in salmon liver. However, it is not known whether this is associated with changes in the DNA methylation of genes involved in polyunsaturated fatty acid synthesis. To address this, we investigated whether changing the proportions of dietary FO and vegetable oil altered the DNA methylation of Δ6fad_b, Δ5fad, Elovl2, and Elovl5_b promoters in liver and muscle from Atlantic salmon and whether any changes were associated with mRNA expression. Higher dietary FO content increased the proportions of 20:5n-3 and 22:6n-3 and decreased Δ6fad_b mRNA expression in liver, but there was no effect on Δ5fad, Elovl2, and Elovl5_b expression. There were significant differences between liver and skeletal muscle in the methylation of individual CpG loci in all four genes studied. Methylation of individual Δ6fad_b CpG loci was negatively related to its expression and to proportions of 20:5n-3 and 22:6n-3 in the liver. These findings suggest variations in dietary FO can induce gene-, CpG locus-, and tissue-related changes in DNA methylation in salmon.

Effect of omega-3 fatty acids on cognition: an updated systematic review of randomized clinical trials

Context

The increasing number of studies on the effects of n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) on health, particularly cognition, in the last 5 years reflects the growing interest in this area of research.

Objective

The aim for this systematic review was to evaluate the scientific evidence published in the last 5 years (2012-2017) on the effects of n-3 LC-PUFA intake on cognition, cognitive development, and cognitive decline to determine whether n-3 LC-PUFAs support cognitive development and prevent cognitive decline.

Data Sources

The PubMed database was searched.

Study Selection

The 51 articles included in this systematic review reported on healthy individuals with mild or moderate cognitive impairment and patients with Alzheimer's disease. Risk of bias was assessed using Cochrane methodology.

Data Extraction

The number of study participants, the type of study, the type and dose of n-3 LC-PUFAs, and the key results are reported here.

Results

Current evidence indicates that n-3 LC-PUFAs administered during pregnancy or breastfeeding have no effect on the skills or cognitive development of children in later stages of development. Evidence regarding the improvement of cognitive function during childhood and youth or in attention deficit/hyperactivity disorder is inconclusive. Moreover, it is still unclear if n-3 LC-PUFAs can improve cognitive development or prevent cognitive decline in young or older adults.

Effect of 1 Year Krill Oil Supplementation on Cognitive Achievement of Dutch Adolescents: A Double-Blind Randomized Controlled Trial

Long-chain polyunsaturated fatty acids (LCPUFA) are important for brain development and function, maybe especially during adolescence. Observational studies have demonstrated an association between fish consumption (a source of LCPUFA) and cognition in adolescents, but intervention trials are lacking. The goal of the current study was to investigate the effect of one year of krill oil (a source of LCPUFA) supplementation on the cognitive performance of adolescents with a low Omega-3 Index (O3I ≤ 5%). A double-blind, randomized, and placebo-controlled supplementation trial with repeated measurements (baseline (T0), three months (T1), six months (T2), and 12 months (T3)) in adolescents (267 randomized) was executed. Participants were randomized to 400 mg eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) per day in Cohort I or placebo and 800 mg EPA + DHA per day in Cohort II or placebo. O3I was monitored by a finger prick at all time points. At T0, T2, and T3, participants executed a neurocognitive test battery. Covariate corrected mixed models were run with either condition (krill or placebo) or O3I as predictors. Krill oil supplementation led to a small but significant increase in mean O3I, but few participants increased to the intended O3I range (8–11%). There was no significant effect of supplementation on the neurocognitive tests, nor a relationship between O3I and neurocognitive test scores. The increase in O3I was small in most participants, probably due to non-compliance. Possibly the increase in O3I was too small to demonstrate an effect. More research on the influence of LCPUFAs on cognition in adolescents is needed.

Exploring correlations between neuropsychological measures and domain-specific consistency in associations with n-3 LCPUFA status in 8-9 year-old boys and girls

Long-chain n-3 polyunsaturated fatty acids (n-3 LCPUFA) have in some studies been associated with cognitive and socioemotional outcomes in children, but results are inconsistent possibly due to the use of different tests and potential gender-specific effects. The objective of this cross-sectional study was to explore overall patterns in neuropsychological scores as well as correlations between scores within specific domains, and to examine potential gender differences and consistency in associations with n-3 LCPUFA status. In 199 Danish 8–9 year-old children, we performed a large battery of tests and questionnaires on attention, processing speed, executive functions, memory, and socioemotional traits, and measured erythrocyte fatty acid composition. Principal component analyses (PCA) showed that most of the variation in both cognitive performance and socioemotional traits was explained by overall performance, followed by speed-accuracy trade off and externalizing vs. internalizing problems, respectively. Boys had higher speed, lower attention and higher externalizing problem scores than girls. Measures of performance within both processing speed and attention domains correlated moderately, whereas no correlations were found for measures of executive functions apart from some weak correlations for impulsivity. Parent-rated scores for both externalizing and internalizing problems correlated strongly, whereas correlations with child-rated scores were weak. Scores within specific domains did not consistently associate with n-3 LCPUFA, except for processing speed measures which all pointed to faster processing with increased n-3 LCPUFA status. Gender differences in the associations were observed for attention and impulsivity. Child- but not parent-rated internalizing and social problems tended to associate directly with n-3 LCPUFA, supported by increased internalizing problems measured by the PCA component. In conclusion, measures of speed and attention seem to represent these domains in general, whereas single measures of more complex cognitive functions should be interpreted with caution. One approach could be to use multiple tests and create multivariate scores to guide interpretations. Furthermore, the results indicate a need to consider both parent- and child-rated socioemotional scores and gender differences in neuropsychological functions e.g. in investigations of n-3 LCPUFA effects.

Erythrocyte DHA and AA in infancy is not associated with developmental status and cognitive functioning five years later in Nepalese children

BACKGROUND

Long chain polyunsaturated fatty acids (LCPUFA) especially docosahexaenoic acid (DHA) and arachidonic acid (AA) are crucial for normal brain development in utero and in early infancy. Data on fatty acid status and cognitive development in infants and children from low-income countries are scarce.

METHODS

We examined the association between the DHA and AA status in infancy (n = 320) and developmental status and cognitive functioning five years later. At five years of age, we measured development by the Ages and Stages Questionnaire 3rd. ed. (ASQ-3) and cognitive functioning by subtests from the neuropsychological test battery NEPSY II. In addition, infant fatty acid composition in red blood cells (RBC) was analyzed. In multiple linear and logistic regression models, we estimated the associations between DHA and AA status in infancy and scores on the ASQ-3 and the NEPSY II subtests.

RESULTS

There were no notable associations between infant AA and DHA status, and the scores on the ASQ-3 and the NEPSY II subtests five years later. It should be noted that we found better than expected concentrations of erythrocyte DHA and AA among the infants, and the ASQ scores were left-skewed, which limited the ability to identify associations.

CONCLUSION

DHA and AA status in infancy is seemingly not related to neurodevelopment measured 5 years later in this peri-urban population from Nepal.

Association between fish consumption and risk of dementia: a new study from China and a systematic literature review and meta-analysis

Objective

To assess the association of fish consumption with risk of dementia and its dose–response relationship, and investigate variations in the association among low-, middle- and high-income countries.

Design

A new community-based cross-sectional study and a systematic literature review.

Settings

Urban and rural communities in China; population-based studies systematically searched from worldwide literature.

Subjects

Chinese adults aged ≥60 years in six provinces (n 6981) took part in a household health survey of dementia prevalence and risk factors. In addition, 33 964 participants from eleven published and eligible studies were included in the systematic review and meta-analysis.

Results

In the new study in China, 326 participants were diagnosed with dementia (4·7 %); those who consumed any amount of fish in the past two years v. those who consumed no fish had reduced risk of dementia (adjusted OR=0·73, 95 % CI 0·64, 0·99), but the dose–response relationship was not statistically significant. The meta-analysis of available data from the literature and the new study showed relative risk (RR) of dementia of 0·80 (95 % CI 0·74, 0·87) for people with fish consumption; the impact was similar among countries with different levels of income. Pooled dose–response data revealed RR (95 % CI) of 0·84 (0·72, 0·98), 0·78 (0·68, 0·90) and 0·77 (0·61, 0·98) in people with low, middle and high consumption of fish, respectively. Corresponding figures for Alzheimer’s disease were 0·88 (0·74, 1·04), 0·79 (0·65, 0·96) and 0·67 (0·58, 0·78), respectively.

Conclusions

Greater consumption of fish is associated with a lower risk of dementia. Increasing fish consumption may help prevent dementia worldwide regardless of income level.

The complete European guidelines on phenylketonuria: diagnosis and treatment

Phenylketonuria (PKU) is an autosomal recessive inborn error of phenylalanine metabolism caused by deficiency in the enzyme phenylalanine hydroxylase that converts phenylalanine into tyrosine. If left untreated, PKU results in increased phenylalanine concentrations in blood and brain, which cause severe intellectual disability, epilepsy and behavioural problems. PKU management differs widely across Europe and therefore these guidelines have been developed aiming to optimize and standardize PKU care. Professionals from 10 different European countries developed the guidelines according to the AGREE (Appraisal of Guidelines for Research and Evaluation) method. Literature search, critical appraisal and evidence grading were conducted according to the SIGN (Scottish Intercollegiate Guidelines Network) method. The Delphi-method was used when there was no or little evidence available. External consultants reviewed the guidelines. Using these methods 70 statements were formulated based on the highest quality evidence available. The level of evidence of most recommendations is C or D. Although study designs and patient numbers are sub-optimal, many statements are convincing, important and relevant. In addition, knowledge gaps are identified which require further research in order to direct better care for the future.

Combination of EPA with Carotenoids and Polyphenol Synergistically Attenuated the Transformation of Microglia to M1 Phenotype Via Inhibition of NF-κB

Microglia activation toward the M1 phenotype has been reported to contribute to the neurodegenerative processes and cognition alterations due to the release of pro-inflammatory mediators and cytokines. The aim of the present research was to assess the effectiveness of free fatty acids omega-3 preparations: eicosapentaenoic acid (EPA) or/and docosahexaenoic acid (DHA), carotenoids and phenolics combinations, in inhibiting the release of inflammatory mediators from activated microglia. Preincubation of BV-2 microglia cells with each of the FFAs omega-3 preparations in a range of 0.03-2 μM together with Lyc-O-mato^® (0.1 μM), Carnosic acid (0.2 μM) with or without Lutein (0.2 μM), 1 h before addition of lipopolysaccharide (LPS) for 16 h caused a synergistic inhibition of nitric oxide (NO) production with a rank order of EPA > Ropufa (EPA/DHA 2/1) > Krill (EPA/DHA 1.23/1). The optimal inhibitory combinations of EPA (0.125 μM) with the phytonutrients caused a synergistic inhibition of prostaglandin E₂ (PGE₂) release, IL-6 secretion, superoxide and NO production and prevention of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) upregulation and elevated CD40 expression in microglia exposed to LPS or interferon-γ (IFN-γ), representing infection or inflammation, respectively. The presence of the combination caused a synergistic increase in the release of the anti-inflammatory cytokine IL-10. The inhibitory effects by the combinations of EPA with the phytonutrients were mediated by the inhibition of the redox-sensitive NF-κB activation and detected by its phosphorylated p-65 on serine 536 in microglia stimulated by either LPS or IFN-γ. In addition, phosphorylated CREB on serine 133 which was shown to be involved in the induction of iNOS was inhibited by the combinations in stimulated cells. In conclusion, the results suggest that low concentrations of EPA with the phytonutrients are very efficient in inhibiting the transformation of microglia to M1 phenotype and may prevent cognition deficit.

A Review of Recruitment, Adherence and Drop-Out Rates in Omega-3 Polyunsaturated Fatty Acid Supplementation Trials in Children and Adolescents

INTRODUCTION

The influence of n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) supplementation on health outcomes has been studied extensively with randomized controlled trials (RCT). In many research fields, difficulties with recruitment, adherence and high drop-out rates have been reported. However, what is unknown is how common these problems are in n-3 LCPUFA supplementation studies in children and adolescents. Therefore, this paper will review n-3 LCPUFA supplementation studies in children and adolescents with regard to recruitment, adherence and drop-out rates.

METHODS

The Web of Science, PubMed and Ovid databases were searched for papers reporting on RCT supplementing children and adolescents (2-18 years) with a form of n-3 LCPUFA (or placebo) for at least four weeks. As a proxy for abiding to CONSORT guidelines, we noted whether manuscripts provided a flow-chart and provided dates defining the period of recruitment and follow-up.

RESULTS

Ninety manuscripts (reporting on 75 studies) met the inclusion criteria. The majority of the studies did not abide by the CONSORT guidelines: 55% did not provide a flow-chart, while 70% did not provide dates. The majority of studies provided minimal details about the recruitment process. Only 25 of the 75 studies reported an adherence rate which was on average 85%. Sixty-five of the 75 studies included drop-out rates which were on average 17%.

CONCLUSION

Less than half of the included studies abided by the CONSORT guidelines (45% included a flow chart, while 30% reported dates). Problems with recruitment and drop-out seem to be common in n-3 LCPUFA supplementation trials in children and adolescents. However, reporting about recruitment, adherence and dropout rates was very heterogeneous and minimal in the included studies. Some techniques to improve recruitment, adherence and dropout rates were identified from the literature, however these techniques may need to be tailored to n-3 LCPUFA supplementation studies in children and adolescents.

Long-chain omega-3 fatty acids and optimization of cognitive performance

Low consumption of the omega-3 fatty acids, eicosapentaenoic and docosahexaenonic acids, is linked to delayed brain development and, in late life, increased risk for Alzheimer's disease. The current review focuses on cognitive functioning during midlife and summarizes available scientific evidence relevant to the hypothesis that adequate dietary consumption of the long-chain omega-3 fatty acids is necessary for optimal cognitive performance. Taken together, the findings suggest that raising the currently low consumption among healthy adults may improve some aspects of cognitive performance. Nonetheless, evidence from randomized clinical trials is comparatively sparse and leaves unclear: (a) whether such effects are clinically significant, (b) whether effects of eicosapentaenoic acid and DHA differ, (c) which dimensions of cognitive function are affected, (d) the dose-response relationships, or (e) the time course of the response. Clarification of these issues through both laboratory and clinical investigations is a priority given the broad implications for public health, as well as for military personnel and other positions of high performance demand and responsibility.

Natural lecithin promotes neural network complexity and activity

Phospholipids in the brain cell membranes contain different polyunsaturated fatty acids (PUFAs), which are critical to nervous system function and structure. In particular, brain function critically depends on the uptake of the so-called "essential" fatty acids such as omega-3 (n-3) and omega-6 (n-6) PUFAs that cannot be readily synthesized by the human body. We extracted natural lecithin rich in various PUFAs from a marine source and transformed it into nanoliposomes. These nanoliposomes increased neurite outgrowth, network complexity and neural activity of cortical rat neurons in vitro. We also observed an upregulation of synapsin I (SYN1), which supports the positive role of lecithin in synaptogenesis, synaptic development and maturation. These findings suggest that lecithin nanoliposomes enhance neuronal development, which may have an impact on devising new lecithin delivery strategies for therapeutic applications.

Comparison of Formulas Based on Lipid Emulsions of Olive Oil, Soybean Oil, or Several Oils for Parenteral Nutrition: A Systematic Review and Meta-Analysis

Many studies have reported that olive oil-based lipid emulsion (LE) formulas of soybean oil, medium-chain triglycerides, olive oil, and fish oil (SMOF) may be a viable alternative for parenteral nutrition. However, some randomized controlled clinical trials (RCTs) have raised concerns regarding the nutritional benefits and safety of SMOFs. We searched principally the MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Scopus, EMBASE, and Cochrane Central Register of Controlled Trials databases from inception to March 2014 for the relevant literature and conducted a meta-analysis of 15 selected RCTs that 1) compared either olive oil- or SMOF-based LEs with soybean oil-based LEs and 2) reported plasma concentrations of α-tocopherol, oleic acid, and ω-6 (n-6) and ω-3 (n-3) long-chain polyunsaturated fatty acids (PUFAs) and liver concentrations of total bilirubin and the enzymes alanine transaminase, aspartate transaminase, alkaline phosphatase, and γ-glutamyl transferase. The meta-analysis suggested that SMOF-based LEs were associated with higher plasma concentrations of plasma α-tocopherol, oleic acid, and the ω-3 PUFAs eicosapentaenoic and docosahexaenoic acid. Olive oil- and SMOF-based LEs correlated with lower plasma concentrations of long-chain ω-6 PUFAs and were similar to soybean oil-based LEs with regard to their effects on liver function indicators. In summary, olive oil- and SMOF-based LEs have nutritional advantages over soybean oil-based LEs and are similarly safe. However, their performance in clinical settings requires further investigation.

Docosahexaenoic Acid and Cognition throughout the Lifespan

Docosahexaenoic acid (DHA) is the predominant omega-3 (n-3) polyunsaturated fatty acid (PUFA) found in the brain and can affect neurological function by modulating signal transduction pathways, neurotransmission, neurogenesis, myelination, membrane receptor function, synaptic plasticity, neuroinflammation, membrane integrity and membrane organization. DHA is rapidly accumulated in the brain during gestation and early infancy, and the availability of DHA via transfer from maternal stores impacts the degree of DHA incorporation into neural tissues. The consumption of DHA leads to many positive physiological and behavioral effects, including those on cognition. Advanced cognitive function is uniquely human, and the optimal development and aging of cognitive abilities has profound impacts on quality of life, productivity, and advancement of society in general. However, the modern diet typically lacks appreciable amounts of DHA. Therefore, in modern populations, maintaining optimal levels of DHA in the brain throughout the lifespan likely requires obtaining preformed DHA via dietary or supplemental sources. In this review, we examine the role of DHA in optimal cognition during development, adulthood, and aging with a focus on human evidence and putative mechanisms of action.

Docosahexaenoic Acid and Cognition throughout the Lifespan

Docosahexaenoic acid (DHA) is the predominant omega-3 (n-3) polyunsaturated fatty acid (PUFA) found in the brain and can affect neurological function by modulating signal transduction pathways, neurotransmission, neurogenesis, myelination, membrane receptor function, synaptic plasticity, neuroinflammation, membrane integrity and membrane organization. DHA is rapidly accumulated in the brain during gestation and early infancy, and the availability of DHA via transfer from maternal stores impacts the degree of DHA incorporation into neural tissues. The consumption of DHA leads to many positive physiological and behavioral effects, including those on cognition. Advanced cognitive function is uniquely human, and the optimal development and aging of cognitive abilities has profound impacts on quality of life, productivity, and advancement of society in general. However, the modern diet typically lacks appreciable amounts of DHA. Therefore, in modern populations, maintaining optimal levels of DHA in the brain throughout the lifespan likely requires obtaining preformed DHA via dietary or supplemental sources. In this review, we examine the role of DHA in optimal cognition during development, adulthood, and aging with a focus on human evidence and putative mechanisms of action.

DHA Effects in Brain Development and Function

Docosahexaenoic acid (DHA) is a structural constituent of membranes specifically in the central nervous system. Its accumulation in the fetal brain takes place mainly during the last trimester of pregnancy and continues at very high rates up to the end of the second year of life. Since the endogenous formation of DHA seems to be relatively low, DHA intake may contribute to optimal conditions for brain development. We performed a narrative review on research on the associations between DHA levels and brain development and function throughout the lifespan. Data from cell and animal studies justify the indication of DHA in relation to brain function for neuronal cell growth and differentiation as well as in relation to neuronal signaling. Most data from human studies concern the contribution of DHA to optimal visual acuity development. Accumulating data indicate that DHA may have effects on the brain in infancy, and recent studies indicate that the effect of DHA may depend on gender and genotype of genes involved in the endogenous synthesis of DHA. While DHA levels may affect early development, potential effects are also increasingly recognized during childhood and adult life, suggesting a role of DHA in cognitive decline and in relation to major psychiatric disorders.

Effect of Sardina pilchardus oil on alloxan-induced diabetic rats

The purpose of this study was to prevent or to delay the onset of diabetes-related complications, by using a natural marine resource, Sardina pilchardus oil, administrated to alloxan-induced diabetic rats showing hyperglycemia and hyperlipidemia. Gas chromatography-mass spectrometry analysis of the sardine oil detected 18 constituents. The major ones were n-3 highly unsaturated fatty acids among which are docosahexaenoic acid (25.09%) and eicosapentaenoic acid (19.61%). Sardine oil inhibited the α-amylase activity in rats' sera (26.82%) and thus improved glycemia (54%). The supplement of this oil protected the β-cells from death and damage, significantly decreased total triglycerides, total cholesterol and LDL-cholesterol concentrations in diabetic rats' sera and increased the HDL-cholesterol level. Gavage administration of this oil to rats protected the liver and kidney functions by reducing the aspartate transaminase, alanine transaminase and phosphatase alkaline activities, and by decreasing creatinine, urea and uric acid levels.

Omega-3 long-chain polyunsaturated fatty acids and fish oil supplementation during pregnancy: which evidence?

OBJECTIVE

The aim of this study was to provide evidence-based recommendations for omega-3 supplementation during pregnancy through a systematic review of level-1 data published on this topic.

METHODS

We reviewed all randomized-controlled trials (RCTs) including women who were randomized to treatment with either omega-3 supplementation or control (placebo or no treatment) during pregnancy and analyzed all the outcomes reported in the trials, separately. We planned to evaluate the effect of omega-3 on: preterm birth (PTB); pre-eclampsia (PE) and intrauterine growth restriction (IUGR); gestational diabetes; perinatal mortality; small for gestational age (SGA) and birth weight; infant eye and brain development; and postpartum depression.

RESULTS

We identified 34 RCTs including 14 106 singletons and 2578 twins. These level-1 data showed that omega-3 was not associated with prevention of PTB, PE, IUGR, gestational diabetes, SGA, post-partum depression or better children development. Data about birth weight, perinatal mortality and childhood cognitive outcome were limited. Women with gestational diabetes who received omega-3 had significantly lower serum C-reactive protein concentrations, low incidence of hyperbilirubinemia in newborns and decreased newborns' hospitalization rate.

CONCLUSIONS

There was not enough evidence to support the routine use of omega-3 supplementation during pregnancy. Given the 73% significant decrease in perinatal death in the singleton gestations who started omega-3 supplementation ≤ 20 weeks, further research is needed. Large RCTs in multiple gestations and longer follow-up are also required.

Reduced Symptoms of Inattention after Dietary Omega-3 Fatty Acid Supplementation in Boys with and without Attention Deficit/Hyperactivity Disorder

Attention deficit/hyperactivity disorder (ADHD) is one of the most common child psychiatric disorders, and is often treated with stimulant medication. Nonpharmacological treatments include dietary supplementation with omega-3 fatty acids, although their effectiveness remains to be shown conclusively. In this study, we investigated the effects of dietary omega-3 fatty acid supplementation on ADHD symptoms and cognitive control in young boys with and without ADHD. A total of 40 boys with ADHD, aged 8-14 years, and 39 matched, typically developing controls participated in a 16-week double-blind randomized placebo-controlled trial. Participants consumed 10 g of margarine daily, enriched with either 650 mg of eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) each or placebo. Baseline and follow-up assessments addressed ADHD symptoms, fMRI of cognitive control, urine homovanillic acid, and cheek cell phospholipid sampling. EPA/DHA supplementation improved parent-rated attention in both children with ADHD and typically developing children. Phospholipid DHA level at follow-up was higher for children receiving EPA/DHA supplements than placebo. There was no effect of EPA/DHA supplementation on cognitive control or on fMRI measures of brain activity. This study shows that dietary supplementation with omega-3 fatty acids reduces symptoms of ADHD, both for individuals with ADHD and typically developing children. This effect does not appear to be mediated by cognitive control systems in the brain, as no effect of supplementation was found here. Nonetheless, this study offers support that omega-3 supplementation may be an effective augmentation for pharmacological treatments of ADHD (NCT01554462: The Effects of EPA/DHA Supplementation on Cognitive Control in Children with ADHD; http://clinicaltrials.gov/show/NCT01554462).

Changes in the physiological parameters, fatty acid metabolism, and SCD activity and expression in juvenile GIFT tilapia (Oreochromis niloticus) reared at three different temperatures

We evaluated the effects of rearing temperature on the composition of fatty acids and stearoyl-CoA desaturase (SCD) activity and gene expression in GIFT (genetically improved farmed tilapia) tilapia. Three triplicate groups of fish were reared for 40 days at 22, 28, or 34 °C. At the end of the trial, the final body weight of juveniles reared at 28 °C was higher than that of fish reared at 22 or 34 °C. Feed intake, feed efficiency, and the protein efficiency ratio were also higher at 28 °C. The fatty acid composition of muscle tissue differed significantly (P < 0.05) among the treatment groups. The content of SFA decreased with decreasing temperature, whereas the UFA content increased. We observed high levels of PUFA, particularly n-3 PUFAs, in fish reared at the lower temperature. Rearing at low temperature significantly (P < 0.05) increased the expression and activity of the SCD gene. Increased SCD activity and gene expression can increase the biosynthesis of MUFAs in GIFT tilapia muscle. Additionally, cold acclimation can decrease the content of TC and TG in GIFT tilapia, which can help increase cold tolerance.

IV. The cognitive implications of obesity and nutrition in childhood

The prevalence of childhood obesity in the United States has tripled since the 1980s and is strongly linked to the early onset of several metabolic diseases. Recent studies indicate that lower cognitive function may be another complication of childhood obesity. This review considers the research to date on the role of obesity and nutrition on childhood cognition and brain health. Although a handful of studies point to a maladaptive relationship between obesity and aspects of cognitive control, remarkably little is known regarding the impact of fat mass on brain development and cognitive function. Further, missing from the literature is the role of nutrition in the obesity-cognition interaction. Nutrition may directly or indirectly influence cognitive performance via several pathways including provision of key substrates for optimal brain health, modulation of gut microbiota, and alterations in systemic energy balance. However, in the absence of malnutrition, the functional benefits of specific nutrient intake on particular cognitive domains are not well characterized. Here, we examine the literature linking childhood obesity and cognition while considering the effects of nutritional intake. Possible mechanisms for these relationships are discussed and suggestions are made for future study topics. Although childhood obesity prevalence rates in some developed countries have recently stabilized, significant disparities remain among groups based on sex and socioeconomic status. Given that the elevated prevalence of pediatric overweight and obesity may persist for the foreseeable future, it is crucial to develop a comprehensive understanding of the influence of obesity and nutrition on cognition and brain health in the pediatric population.

Maternal choline supplementation programs greater activity of the phosphatidylethanolamine N-methyltransferase (PEMT) pathway in adult Ts65Dn trisomic mice

Maternal choline supplementation (MCS) induces lifelong cognitive benefits in the Ts65Dn mouse, a trisomic mouse model of Down syndrome and Alzheimer's disease. To gain insight into the mechanisms underlying these beneficial effects, we conducted a study to test the hypothesis that MCS alters choline metabolism in adult Ts65Dn offspring. Deuterium-labeled methyl-d9-choline was administered to adult Ts65Dn and disomic (2N) female littermates born to choline-unsupplemented or choline-supplemented Ts65Dn dams. Enrichment of d9-choline metabolites (derived from intact choline) and d3 + d6-choline metabolites [produced when choline-derived methyl groups are used by phosphatidylethanolamine N-methyltransferase (PEMT)] was measured in harvested tissues. Adult offspring (both Ts65Dn and 2N) of choline-supplemented (vs. choline-unsupplemented) dams exhibited 60% greater (P≤0.007) activity of hepatic PEMT, which functions in de novo choline synthesis and produces phosphatidylcholine (PC) enriched in docosahexaenoic acid. Higher (P<0.001) enrichment of PEMT-derived d3 and d6 metabolites was detected in liver, plasma, and brain in both genotypes but to a greater extent in the Ts65Dn adult offspring. MCS also yielded higher (P<0.05) d9 metabolite enrichments in liver, plasma, and brain. These data demonstrate that MCS exerts lasting effects on offspring choline metabolism, including up-regulation of the hepatic PEMT pathway and enhanced provision of choline and PEMT-PC to the brain.

Cloning, functional characterization and nutritional regulation of Δ6 fatty acyl desaturase in the herbivorous euryhaline teleost Scatophagus argus

Marine fish are generally unable or have low ability for the biosynthesis of long-chain polyunsaturated fatty acids (LC-PUFA) from C18 PUFA precursors, with some notable exceptions including the herbivorous marine teleost Siganus canaliculatus in which such a capability was recently demonstrated. To determine whether this is a unique feature of S. canaliculatus or whether it is common to the herbivorous marine teleosts, LC-PUFA biosynthetic pathways were investigated in the herbivorous euryhaline Scatophagus argus. A putative desaturase gene was cloned and functionally characterized, and tissue expression and nutritional regulation were investigated. The full-length cDNA was 1972 bp, containing a 1338 bp open-reading frame encoding a polypeptide of 445 amino acids, which possessed all the characteristic features of fatty acyl desaturase (Fad). Functional characterization by heterologous expression in yeast showed the protein product of the cDNA efficiently converted 18:3n-3 and 18:2n-6 to 18:4n-3 and 18:3n-6, respectively, indicating Δ6 desaturation activity. Quantitative real-time PCR showed that highest Δ6 fad mRNA expression was detected in liver followed by brain, with lower expression in other tissues including intestine, eye, muscle, adipose, heart kidney and gill, and lowest expression in stomach and spleen. The expression of Δ6 fad was significantly affected by dietary lipid and, especially, fatty acid composition, with highest expression of mRNA in liver of fish fed a diet with a ratio of 18:3n-3/18:2n-6 of 1.72:1. The results indicated that S. argus may have a different LC-PUFA biosynthetic system from S. canaliculatus despite possessing similar habitats and feeding habits suggesting that LC-PUFA biosynthesis may not be common to all marine herbivorous teleosts.

An update on adding docosahexaenoic acid (DHA) and arachidonic acid (AA) to baby formula

Human milk is the ideal food providing optimal nutrition for healthy term infants. Its complex lipid composition is critical for infant growth and serves as a golden standard for baby formula development. Docosahexaenoic acid (C22:6 n- 3, DHA) and arachidonic acid (C20:4 n- 6, AA) are the two major long chain polyunsaturated fatty acids (PUFAs) in human milk. In humans, they are fundamental components of the cell membrane and play an important role in neurite growth and signal transmission. Their importance for both preterm and term infants has been demonstrated by various clinical trials. DHA and AA supplementation shows desirable influences on visual and cognitive development in early life and is additionally associated with potential benefits on later health. Further clinical data revealed that supplementing both DHA and AA instead of DHA alone during infancy is important to deliver the optimal outcome. In this review, we summarize current research and scientific evidence of DHA and AA on baby development.

Docosahexaenoic acid status at 9 months is inversely associated with communicative skills in 3-year-old girls

The objective of the present observational study was to investigate if the docosahexaenoic acid (DHA) status assessed in infant erythrocytes (RBC) at 9 months was associated with the age when the infants reach developmental milestones and their psychomotor function at 3 years of age. Three hundred eleven healthy Danish children were followed from 9 months to 3 years of age (the SKOT cohort). RBC fatty acid composition was analysed by gas chromatography in 272 of the children. Milestone age was collected by questionnaires at 9 and 18 months and psychomotor development at 3 years of age was assessed by the parents using third edition of the Ages and Stages Questionnaire (ASQ-3). RBC DHA levels ranged from 2.2% to 12.6% of the RBC fatty acids. The age of reaching milestones correlated with psychomotor development, particularly with gross motor function at 3 years. An association between milestones and later personal and social skills was also observed, but only for girls. In girls, RBC-DHA was found to be inversely correlated with communication at 3 years of age (odds ratio = 0.69, 95% confidence interval: 0.56-0.86, P = 0.001), but no other associations with psychomotor development or milestones were found. The results from study indicate that DHA status at 9 months may not have a pronounced beneficial effect on psychomotor development in early childhood and that communicative skills at 3 years of age may even be inversely associated with early RBC-DHA levels in girls.