Polyunsaturated Fatty Acid Deficiency Research Articles

Abstract 400: Determining the Contribution of Endothelial Lipase-mediated Lipolysis to Brain Phospholipid Metabolism

Polyunsaturated fatty acids (PUFA) are essential constituents of the cell membrane. Brain PUFA content is critical for synaptic function and neuroinflammation and PUFA deficiency may underlie several neurological disorders. Prior work in murine models has showed that the predominant source of central nervous system (CNS) PUFAs is 2-acyl-lysophophatidylcholine (2-lysoPC), a class of phospholipids (PLs) circulating on blood lipoproteins that is formed from the enzymatic activity of phospholipases. Endothelial lipase (EL) is a phospholipase that is a critical determinant of HDL metabolism in humans and the predominant generator of 2-lysoPC on HDL particles. While the contribution of EL to circulating HDL metabolism is well-established, its contribution to CNS fatty acid availability and brain function has not been explored. In order to investigate the physiological contribution of EL to brain FA availability in vivo, we studied PL-derived PUFA uptake in mice with EL deficiency. We adopted a method for measuring EL activity using a fluorescent synthetic HDL particle containing sn2-TopFluor-PC, a fluorescent precursor of 2-lysoPC and demonstrated its utility in vitro. Next, we tested the clearance of this synthetic HDL-derived 2-lysoPC in C57BL/6 (WT) vs EL KO mice (n=12/group). Circulating plasma 2-lysoPC clearance was significantly impaired in in EL KO mice (-32%, p=0.024) and was accompanied by a slower remodeling of the HDL particles. Measurement of labeled PL content in tissues showed a significant reduction in hepatic uptake in KO mice (22% decrease, p=0.002). No significant differences were observed in total brain PL uptake, but the distribution of PL uptake differed between WT and KOs. Ongoing studies are evaluating the physiological consequences of reduced circulating 2-lysoPC clearance, reduced hepatic uptake, and altered distribution of brain PL uptake in EL KO mice. Collectively, our data demonstrate that EL is a key physiological regulator of systemic PL catabolism.

Meta-analysis of erythrocyte polyunsaturated fatty acid biostatus in bipolar disorder.

Dietary deficiency in polyunsaturated fatty acids (PUFAs), including the omega-3 fatty acids eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3), and excesses in omega-6 fatty acids, including linoleic acid (LA; 18:2n-6) and arachidonic acid (AA; 20:4n-6), may be associated with the pathophysiology of bipolar disorder. In an effort to provide clarification regarding the relationship between PUFA biostatus and bipolar disorder, this meta-analysis investigated studies comparing erythrocyte (red blood cell) membrane PUFA composition in patients with bipolar disorder and healthy controls. A meta-analysis was performed on case-control studies comparing erythrocyte PUFA (EPA, DHA, LA and AA) levels in patients with bipolar I disorder and healthy controls. Standardized effect sizes were calculated and combined using a random effects model. Six eligible case-control studies comprising n = 118 bipolar I patients and n = 147 healthy controls were included in the analysis. Compared with healthy controls, patients with bipolar I disorder exhibited robust erythrocyte DHA deficits (p = 0.0008) and there was a trend for lower EPA (p = 0.086). There were no significant differences in LA (p = 0.42) or AA (p = 0.64). Bipolar I disorder is associated with robust erythrocyte DHA deficits. These findings add to a growing body of evidence implicating omega-3 PUFA deficiency in the pathophysiology of bipolar disorder.

Nutrition in cachexia: from bench to bedside.

As malnutrition is often present in cachexia, nutritional intervention has been one of the widely accepted strategies. A literature review of cachexia models with dietary interventions in the present issue of this journal pointed out that the majority of nutrient intervention studies were of n‐3 fatty acid, mainly eicosapentaenoic acid and docosahexaenoic acid. Effect on protein catabolism and anti‐inflammation are most pronounced benefits of n‐3 fatty acid. The effectiveness of n‐3 fatty acid may depend on control diet or even be attributed to the polyunsaturated fatty acid deficiency inadvertently produced in control group. However, there is not enough clinical evidence to support a benefit of n‐3 fatty acid substitution in patients with cachexia. The second important result from this review is that the majority of studies did not provide information about dietary design or did not standardize design, content, source, and overall composition. To guide dietary design for researchers in preclinical studies, a model has been proposed in this review, which may be useful to predict the efficacy of new dietary intervention in cachexia science. From a clinical point of view, the limited effectiveness of nutritional support in cachexia may partly be explained by the multifactorial nature of this condition. Cachexia differs from malnutrition inasmuch as malnutrition can be reversed by adequate nutrition and/or by overcoming problems of absorption or utilization of nutrients, but cachexia cannot be successfully treated by nutrition alone. Multidisciplinary approach including the assessment and intervention in feeding, appetite, swallowing, exercise, psychosocial, and psychological issue may be needed to improve nutrition in patients with cachexia.

Nutritional n-3 PUFA Deficiency Abolishes Endocannabinoid Gating of Hippocampal Long-Term Potentiation.

Maternal n-3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid, is critical during perinatal brain development. How early postnatal n-3 PUFA deficiency impacts on hippocampal synaptic plasticity is mostly unknown. Here we compared activity-dependent plasticity at excitatory and inhibitory synapses in the CA1 region of the hippocampus in weaned pups whose mothers were fed with an n-3 PUFA-balanced or n-3 PUFA-deficient diet. Normally, endogenous cannabinoids (eCB) produced by the post-synapse dually control network activity by mediating the long-term depression of inhibitory inputs (iLTD) and positively gating NMDAR-dependent long-term potentiation (LTP) of excitatory inputs. We found that both iLTD and LTP were impaired in n-3 PUFA-deficient mice. Pharmacological dissection of the underlying mechanism revealed that impairment of NMDAR-dependent LTP was causally linked to and attributable to the ablation of eCB-mediated iLTD and associated to disinhibitory gating of excitatory synapses. The data shed new light on how n-3 PUFAs shape synaptic activity in the hippocampus and provide a new synaptic substrate to the cognitive impairments associated with perinatal n-3 deficiency.

Nutritional Omega-3 Deficiency Alters Glucocorticoid Receptor-Signaling Pathway and Neuronal Morphology in Regionally Distinct Brain Structures Associated with Emotional Deficits.

Extensive evidence suggests that long term dietary n-3 polyunsaturated fatty acids (PUFAs) deficiency results in altered emotional behaviour. We have recently demonstrated that n-3 PUFAs deficiency induces emotional alterations through abnormal corticosterone secretion which leads to altered dendritic arborisation in the prefrontal cortex (PFC). Here we show that hypothalamic-pituitary-adrenal (HPA) axis feedback inhibition was not compromised in n-3 deficient mice. Rather, glucocorticoid receptor (GR) signaling pathway was inactivated in the PFC but not in the hippocampus of n-3 deficient mice. Consequently, only dendritic arborisation in PFC was affected by dietary n-3 PUFAs deficiency. In addition, occlusion experiment with GR blockade altered GR signaling in the PFC of control mice, with no further alterations in n-3 deficient mice. In conclusion, n-3 PUFAs deficiency compromised PFC, leading to dendritic atrophy, but did not change hippocampal GR function and dendritic arborisation. We argue that this GR sensitivity contributes to n-3 PUFAs deficiency-related emotional behaviour deficits.

Omega-3 deficiency impairs honey bee learning

Deficiency in essential omega-3 polyunsaturated fatty acids (PUFAs), particularly the long-chain form of docosahexaenoic acid (DHA), has been linked to health problems in mammals, including many mental disorders and reduced cognitive performance. Insects have very low long-chain PUFA concentrations, and the effect of omega-3 deficiency on cognition in insects has not been studied. We show a low omega-6:3 ratio of pollen collected by honey bee colonies in heterogenous landscapes and in many hand-collected pollens that we analyzed. We identified Eucalyptus as an important bee-forage plant particularly poor in omega-3 and high in the omega-6:3 ratio. We tested the effect of dietary omega-3 deficiency on olfactory and tactile associative learning of the economically highly valued honey bee. Bees fed either of two omega-3-poor diets, or Eucalyptus pollen, showed greatly reduced learning abilities in conditioned proboscis-extension assays compared with those fed omega-3-rich diets, or omega-3-rich pollen mixture. The effect on performance was not due to reduced sucrose sensitivity. Omega-3 deficiency also led to smaller hypopharyngeal glands. Bee brains contained high omega-3 concentrations, which were only slightly affected by diet, suggesting additional peripheral effects on learning. The shift from a low to high omega-6:3 ratio in the Western human diet is deemed a primary cause of many diseases and reduced mental health. A similar shift seems to be occurring in bee forage, possibly an important factor in colony declines. Our study shows the detrimental effect on cognitive performance of omega-3 deficiency in a nonmammal.

Lack of Dietary Polyunsaturated Fatty Acids Causes Synapse Dysfunction in the Drosophila Visual System.

Polyunsaturated fatty acids (PUFAs) are essential nutrients for animals and necessary for the normal functioning of the nervous system. A lack of PUFAs can result from the consumption of a deficient diet or genetic factors, which impact PUFA uptake and metabolism. Both can cause synaptic dysfunction, which is associated with numerous disorders. However, there is a knowledge gap linking these neuronal dysfunctions and their underlying molecular mechanisms. Because of its genetic manipulability and its easy, fast, and cheap breeding, Drosophila melanogaster has emerged as an excellent model organism for genetic screens, helping to identify the genetic bases of such events. As a first step towards the understanding of PUFA implications in Drosophila synaptic physiology we designed a breeding medium containing only very low amounts of PUFAs. We then used the fly’s visual system, a well-established model for studying signal transmission and neurological disorders, to measure the effects of a PUFA deficiency on synaptic function. Using both visual performance and eye electrophysiology, we found that PUFA deficiency strongly affected synaptic transmission in the fly’s visual system. These defects were rescued by diets containing omega-3 or omega-6 PUFAs alone or in combination. In summary, manipulating PUFA contents in the fly’s diet was powerful to investigate the role of these nutrients on the fly´s visual synaptic function. This study aims at showing how the first visual synapse of Drosophila can serve as a simple model to study the effects of PUFAs on synapse function. A similar approach could be further used to screen for genetic factors underlying the molecular mechanisms of synaptic dysfunctions associated with altered PUFA levels.

Mitochondrial and Oxidative Stress Aspects in Hippocampus of Rats Submitted to Dietary n-3 Polyunsaturated Fatty Acid Deficiency After Exposure to Early Stress.

Chronic dietary long-chain polyunsaturated fatty acids (PUFAs) deficiency may lead to changes in cortex and hippocampus neuronal membrane phospholipids, and may be linked to impaired central nervous system function. Particularly docosahexaenoic acid deficiency appears to be involved in neuropsychiatric disorders. On the other hand, adverse events early in life may also profoundly affect brain development, leading to long-lasting effects on neurophysiology, neurobiology and behavior. This research assessed if neonatal stress and a dietary n-3 PUFAs deficiency could interact to produce hippocampal alterations related to mitochondrial functions in adult rats. There were no effects of diet, neonatal intervention or interactions on superoxide dismutase or catalase enzymatic activities, mitochondrial membrane potential and respiratory chain complexes. Rats fed n-3 PUFAs deficient diet displayed higher levels of glutathione peroxidase and catalase activity, higher free radicals production and higher thiol content compared to rats fed n-3 PUFAs adequate diet. There were interactions among diets and neonatal stress, since glutathione peroxidase, free radicals production and thiol content were increased in groups that were subjected to neonatal interventions fed n-3 PUFAs deficient diet. Additionally, reduced mitochondrial potential was observed in handled animals. Total thiol revealed a neonatal stress effect, since animals subjected to neonatal interventions displayed lower thiol content. In conclusion, we observed that a chronic treatment with deficient n-3 PUFAs diet, from the puberty period on, increased free radicals production and imbalanced antioxidant enzymes activities, and these increases were higher in animals subjected to neonatal interventions.

Fatty acid composition in Mytilus galloprovincialis organs: trophic interactions, sexual differences and differential anatomical distribution

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 528:221-234 (2015) - DOI: https://doi.org/10.3354/meps11280 Fatty acid composition in Mytilus galloprovincialis organs: trophic interactions, sexual differences and differential anatomical distribution María-José Fernández-Reiriz*, José Luis Garrido, Jade Irisarri Consejo Superior de Investigaciones Científicas (CSIC), Instituto de Investigaciones Marinas (IIM), C/Eduardo Cabello 6, 36208 Vigo, Spain *Corresponding author: mjreiriz@iim.csic.es ABSTRACT: The fatty acid (FA) profiles in neutral lipids (NLs) and polar lipids (PLs) of the gills, digestive gland and mantle of female and male mussels Mytilus galloprovincialis (cultured in Ría de Arousa, Galicia, NW Spain, and studied during an annual seasonal cycle) reflected dietary, sexual and functional differences. Seasonal differences arose from variations in the trophic environment, with diatom FA biomarkers dominating during the spring bloom, biomarkers from dinoflagellate-rich diets dominating during winter mixing, and a combination of both sources apparent during the summer and autumn transitory periods. The influence of diet was more pronounced in the NL (energetic reserves) than in the PL (structural membrane components) FA signatures of all organs, although dietary changes were mirrored more clearly in the digestive gland. Differences between males and females were restricted to the mantle and probably resulted from gonadal ripeness during spring. The NL and PL FA profile of the mantle was characterized by the abundance of 14:0, 16:0 and 16:1n-7 in females and predominance of 18:0, 18:3n-3 and 22:6n-3 in males, suggesting that each gender has distinct energetic and structural requirements during gametogenesis. Lipids containing alkenyl ethers or non-methylene interrupted (NMI) FAs were mostly found in the PLs of the gills and the mantle, supporting their role as structural and functional components in the membranes of organs directly exposed to physicochemical fluctuations. Competition between NMI and polyunsaturated fatty acids (PUFAs) was only evident in the mantle, suggesting that deficiencies in PUFAs might provoke de novo biosynthesis of NMI to satisfy reproductive demands. KEY WORDS: Mussels · Neutral and polar lipids · Non-methylene interrupted fatty acids · Biomarkers · Sexual variation · Bivalve organs Full text in pdf format Supplementary material PreviousNextCite this article as: Fernández-Reiriz MJ, Garrido JL, Irisarri J (2015) Fatty acid composition in Mytilus galloprovincialis organs: trophic interactions, sexual differences and differential anatomical distribution. Mar Ecol Prog Ser 528:221-234. https://doi.org/10.3354/meps11280 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 528. Online publication date: May 28, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.

Dietary n-3 PUFAs Deficiency Increases Vulnerability to Inflammation-Induced Spatial Memory Impairment

Dietary n-3 polyunsaturated fatty acids (PUFAs) are critical components of inflammatory response and memory impairment. However, the mechanisms underlying the sensitizing effects of low n-3 PUFAs in the brain for the development of memory impairment following inflammation are still poorly understood. In this study, we examined how a 2-month n-3 PUFAs deficiency from pre-puberty to adulthood could increase vulnerability to the effect of inflammatory event on spatial memory in mice. Mice were given diets balanced or deficient in n-3 PUFAs for a 2-month period starting at post-natal day 21, followed by a peripheral administration of lipopolysaccharide (LPS), a bacterial endotoxin, at adulthood. We first showed that spatial memory performance was altered after LPS challenge only in n-3 PUFA-deficient mice that displayed lower n-3/n-6 PUFA ratio in the hippocampus. Importantly, long-term depression (LTD), but not long-term potentiation (LTP) was impaired in the hippocampus of LPS-treated n-3 PUFA-deficient mice. Proinflammatory cytokine levels were increased in the plasma of both n-3 PUFA-deficient and n-3 PUFA-balanced mice. However, only n-3 PUFA-balanced mice showed an increase in cytokine expression in the hippocampus in response to LPS. In addition, n-3 PUFA-deficient mice displayed higher glucocorticoid levels in response to LPS as compared with n-3 PUFA-balanced mice. These results indicate a role for n-3 PUFA imbalance in the sensitization of the hippocampal synaptic plasticity to inflammatory stimuli, which is likely to contribute to spatial memory impairment.

Spatial variation in periphyton fatty acid composition in subtropical streams

SummaryBenthic algae play an important role in many stream food webs, not only serving as a major carbon source but also influencing energy transfer as the primary source of polyunsaturated fatty acids (PUFA). Dietary deficiency inPUFAcan limit animal growth and reproduction. AlgalPUFAcontent can vary considerably in response to abiotic factors.We conducted a field investigation in streams in South‐East Queensland, Australia, to identify environmental factors affecting the fatty acid composition of periphyton.Riparian canopy cover andNOx‐Nconcentrations explained most of the observed variation in periphyton fatty acid profiles.NOx‐Nconcentrations showed negative relationships with most saturated fatty acids (SAFA), while mono‐unsaturated fatty acids (MUFA) and the fatty acids 16:0 and 16:1ω7 were negatively correlated with canopy cover. In contrast, the percentage of highly unsaturated fatty acids (HUFA) in periphyton was greater with increasing canopy cover regardless ofNOx‐Nconcentrations.Variation in riparian canopy cover and nutrients gave rise to opposite outcomes in terms of periphyton food quality and quantity. The highest periphyton food quality, measured byHUFAcontent, occurred in streams with high canopy cover and low nutrients, while the highest periphyton food quantity occurred in streams with low canopy cover.Our study suggests that changes in riparian vegetation and/or nutrient inputs can significantly alter the fatty acid content of periphyton, with important implications for aquatic consumers. We recommend that future studies on impacts of riparian clearing or nutrient enrichment in stream ecosystems place more attention on the effects of food quality rather than quantity.

Association Between Omega‐3 Index and Type 2 Diabetes in Older Overweight/Obese People is Sex Dependent

The association between dietary omega‐3 polyunsaturated fatty acid (n‐3PUFA) deficiency and insulin resistance, and type 2 diabetes (T2D) is unclear. The aim of this study was to determine whether there is an association between erythrocyte n‐3PUFA levels (Omega‐3 Index) and T2D in older adults.A cross‐sectional sample of older adults aged 65‐95 years (n=548) was analysed. Outcome measures included: Omega‐3 index (O3I; %EPA + %DHA); fasting blood glucose; plasma insulin; and HbA1c. HOMA‐IR was calculated to determine insulin sensitivity. Odds ratio (OR) for T2D was calculated for each quartile of O3I using the lowest quartile as a reference.There was a significant inverse association between O3I and T2D in overweight and obese females, with an OR for T2D for the first to fourth quartiles respectively: 1.0 (reference), 0.82 (95% CI, 0.31‐2.18), 0.56 (95% CI, 0.21‐1.52), 0.22 (95% CI, 0.06‐0.82) (P‐trend=0.015). Similar trends were seen in overweight males however the relationship did not reach significance. After adjusting for BMI, no associations were found between O3I and fasting blood glucose, insulin, HbA1c or HOMA‐IR.Higher erythrocyte n‐3PUFA status may be protective against obesity‐related insulin resistance and T2D in females. Further research is warranted to further elucidate sex differences and determine whether dietary interventions to improve the O3I may delay or prevent the development of T2D.

Docosahexaenoic acid (DHA): a modulator of microglia activity and dendritic spine morphology.

BackgroundRecent studies have revealed that excessive activation of microglia and inflammation-mediated neurotoxicity are implicated in the progression of several neurological disorders. In particular, chronic inflammation in vivo and exposure of cultured brain cells to lipopolysaccharide (LPS) in vitro can adversely change microglial morphology and function. This can have both direct and indirect effects on synaptic structures and functions. The integrity of dendritic spines, the postsynaptic component of excitatory synapses, dictates synaptic efficacy. Interestingly, dysgenesis of dendritic spines has been found in many neurological diseases associated with ω-3 polyunsaturated fatty acid (PUFA) deficiency and cognitive decline. In contrast, supplemented ω-3 PUFAs, such as docosahexaenoic acid (DHA), can partly correct spine defects. Hence, we hypothesize that DHA directly affects synaptic integrity and indirectly through neuron-glia interaction. Strong activation of microglia by LPS is accompanied by marked release of nitric oxide and formation of lipid bodies (LBs), both dynamic biomarkers of inflammation. Here we investigated direct effects of DHA on synaptic integrity and its indirect effects via microglia in the hippocampal CA1 region.MethodsMicroglia (N9) and organotypic hippocampal slice cultures were exposed to the proinflammagen LPS (100 ng/ml) for 24 h. Biochemical and morphological markers of inflammation were investigated in microglia and CA1 regions of hippocampal slices. As biomarkers of hyperactive microglia, mitochondrial function, nitric oxide release and LBs (number, size, LB surface-associated proteins) were assessed. Changes in synaptic transmission of CA1 pyramidal cells were determined following LPS and DHA (25-50 μM) treatments by recording spontaneous AMPA-mediated miniature excitatory postsynaptic currents (mEPSCs).ResultsMicroglia responded to LPS stimulation with a significant decrease of mitochondrial function, increased nitric oxide production and an increase in the formation of large LBs. LPS treatment led to a significant reduction of dendritic spine densities and an increase in the AMPA-mediated mEPSC inter-event interval (IEI). DHA normalized the LPS-induced abnormalities in both neurons and microglia, as revealed by the restoration of synaptic structures and functions in hippocampal CA1 pyramidal neurons.ConclusionOur findings indicate that DHA can prevent LPS-induced abnormalities (neuroinflammation) by reducing inflammatory biomarkers, thereby normalizing microglia activity and their effect on synaptic function.Electronic supplementary materialThe online version of this article (doi:10.1186/s12974-015-0244-5) contains supplementary material, which is available to authorized users.

Omega‐3 fatty acid supplementation candidates can be selected using fatty acid profiling

The aim of this study was to evaluate the fatty acid (FA) profile in the plasma and erythrocyte membranes of apparently healthy men compared to male patients with various cardiovascular diseases (CVD). The plasma FA profiles were analyzed in five groups of subjects aged 37–57 years: groups 1 and 2 were male voluntary blood donors with a body mass index (BMI) 25.1 ± 1.6, (Group 1, N = 12) and a BMI 32.9 ± 4.5, (Group 2, N = 11) respectively, male patients with chronic heart failure due to dilated cardiomyopathy (Group 3, N = 10), chronic atrial fibrillation without heart failure or coronary heart disease (Group 4, N = 10) and patients after myocardial infarction (Group 5, N = 11). The FA profile in plasma and erythrocytes was measured by gas chromatography (GC) with flame ionization detection and basic plasma lipid parameters were then estimated. Deficiencies of eicosapentaenoic acid and docosahexaenoic acid were found in all the groups of CVD patients and in Group 2 (BMI 32.9 ± 4.5) of this Central European population. Unfavorable alterations in FA composition and clinical biochemistry parameters were found in patients with dilated cardiomyopathy (Group 3). Further, 75% of Group 1 (blood donors) had an average plasma PUFA level in the worst quartile for relative risk of cardiovascular events. Tailored n‐3 PUFA supplementation should be recommended not only for secondary prevention in patients suffering from CVD but also for primary prevention in overweight and obese persons with a proven deficiency.Practical applications: Plasma and erythrocyte membrane n‐3 polyunsaturated fatty acid (PUFA) levels are an important parameter of diet composition as well as a marker of cardiovascular risk. Regular sea fish intake or alternative supplementation with the n‐3 PUFA recommendation is in all probability insufficiently realized, particularly in inland countries. In addition to contemporary guidelines and practice, research is providing data on the use of FA analysis for revealing people with an n‐3 PUFA deficiency. This approach could benefit people suffering from CVD as well as for overweight and obese populations with demonstrated deficiency.Tailored n‐3 PUFA supplementation should be recommended not only for secondary prevention in patients suffering from CVD but also for primary prevention in overweight and obese persons with a proven deficiency.

Association of decreased spermatozoa omega-3 fatty acid levels and increased oxidative DNA damage with varicocele in infertile men: a case control study.

Varicocele is commonly associated with male infertility because it impairs normal sperm morphology and activity. Polyunsaturated fatty acids (PUFA) are important determinants of sperm cell structure and function, but their relationship with varicocele remains unclear. The aim of the present study was to investigate the PUFA composition in spermatozoa of infertile men with varicocele and to evaluate the potential relationship between PUFA and varicocele. This case control study recruited 92 infertile men with varicocele, 99 infertile men without varicocele and 95 fertile male control subjects. Semen morphology and activity parameters were assessed and seminal plasma 8-hydroxy-2-deoxyguanosine (8-OHdG) content was determined by ELISA. Sperm concentrations of omega-3 and omega-6 fatty acids were measured by gas chromatography. Infertile men with varicocele had lower concentrations of omega-3 PUFA, higher omega-6:omega-3 PUFA ratios and greater oxidative DNA damage in spermatozoa compared with infertile men without varicocele and normal subjects. The degree of varicocele and DNA damage was associated with decreased omega-3 PUFA concentrations and semen quality in infertile men with varicocele. The findings suggest that omega-3 PUFA deficiency could be implicated in varicocele-associated infertility, and highlight the need for intervention trials to test the usefulness of omega-3 supplementation in reducing sperm abnormalities in infertile men with varicocele.

Theoretical and Practical Aspects of the Development of a Balanced Lipid Complex of Fat Compositions

In the paper, the effect of the lipid complex in fats and oils on human organism and their role in physiology of nutrition are reviewed. Aspects of impairment of the nutritional status upon fat consumption, in particular, the excess consumption of saturated fats, trans-isomers of fatty acids, and cholesterol and the deficiency of polyunsaturated fatty acids and phospholipids, are discussed. Data on oil and fat in modern structure of nutrition are described. Aspects of the development of balanced fat compositions, accounting for normal physiological needs of modern people for lipids and their structural components, are reviewed. Data on the construction of fatty bases from milk fat, natural, and modified vegetable oils and fats providing for predetermined consumer properties of functional fatty milk products are presented.

A dietary polyunsaturated fatty acid improves consumer performance during challenge with an opportunistic bacterial pathogen.

A dietary deficiency in polyunsaturated fatty acids (PUFAs) and/or sterols can severely constrain growth and reproduction of invertebrate consumers. Single nutrients are potentially assigned to different physiological processes, for example to support defence mechanisms; therefore, lipid requirements of healthy and pathogen-challenged consumers might differ. In an oral exposure experiment, we explored the effects of dietary PUFAs and cholesterol on growth, reproduction and survival of an aquatic key herbivore (Daphnia magna) exposed to an opportunistic pathogen (Pseudomonas sp.). We show that healthy and pathogen-challenged D.magna are strongly albeit differentially affected by the biochemical composition of their food sources. Supplementation of a C20 PUFA-deficient diet with arachidonic acid (ARA) resulted in increased survival and reproduction of pathogen-challenged D.magna. We propose that the observed benefit of consuming an ARA-rich diet during pathogen challenge is conveyed partially via ARA-derived eicosanoids. This study is one of the first to consider the importance of dietary PUFAs in modifying fitness parameters of pathogen-challenged invertebrate hosts. Our results suggest that dietary PUFA supply should receive increased attention in host-microorganisms interactions and invertebrate disease models to better understand and predict disease dynamics in natural populations.

Nutritional omega-3 modulates neuronal morphology in the prefrontal cortex along with depression-related behaviour through corticosterone secretion.

Understanding how malnutrition contributes to depression is building momentum. In the present study we unravel molecular and cellular mechanisms by which nutritional disturbances lead to impaired emotional behaviour in mice. Here we report that nutritional n-3 polyunsaturated fatty acids (PUFA) deficiency induces a chronic stress state reflected by disrupted glucocorticoid receptor (GR)-mediated signalling pathway along with hypothalamic–pituitary–adrenal (HPA) axis hyperactivity. This hyperactivity in turn resulted in neuronal atrophy in the dorsolateral (dl)- and dorsomedial (dm)- prefrontal cortex (PFC) and subsequent mood-related behaviour alterations, similarly to chronic social defeat stress. Supplementation of n-3 PUFA prevented detrimental chronic social defeat stress-induced emotional and neuronal impairments by impeding HPA axis hyperactivity. These results indicate a role for dietary n-3 PUFA in the prevention of HPA axis dysfunction associated with the development of some neuropsychiatric disorders including depression.

LONG-CHAIN POLYUNSATURATED ω-3 AND ω-6 FATTY ACIDS AS ESSENTIAL NUTRIENTS IN DIFFERENT PERIODS OF CHILDHOOD

The authors present modern data on the issue of rational nutrition of children in different periods of childhood. The most frequent types of disorders are listed; insufficient consumption of long-chain polyunsaturated fatty acids is among them. The authors show that this issue is topical not only in Russia, but also in a range of the developed countries. The authors give special attention to classification and biological role of polyunsaturated fatty acids, especially in the development of nervous and immune systems. The authors demonstrated importance of sufficient consumption of long-chain polyunsaturated fatty acids in the period of fetal development for antenatal prevention of atopic disease. The authors list methods of recovery from deficiency of polyunsaturated fatty acids in antenatal and neonatal periods and after the first year of life.

Effects of omega-3 fatty acids on tobacco craving in cigarette smokers: A double-blind, randomized, placebo-controlled pilot study.

Cigarette smoke induces oxidative stress with subsequent polyunsaturated fatty acids (PUFAs) peroxidation. Low concentrations of omega-3 PUFAs can affect neurotransmission, resulting in hypofunctioning of the mesocortical systems associated with reward and dependence mechanisms and thus may increase cigarette craving, hampering smoking cessation efforts. PUFA deficiency, in particular eicosapentaenoic acid (EPA; 20:5 n-3) and docosahexaenoic acid (DHA; 22:6 n-3), has also been linked to reduced psychological health and ability to cope with stress. Although stress is well linked to smoking urges and behavior, no research to date has examined the effects of PUFA supplementation on tobacco craving. In this double-blind, randomized, placebo-controlled pilot study, performed in regular cigarette smokers (n=48), administration of 2710 mg EPA/day and 2040 mg DHA/day for one month was accompanied by a significant decrease in reported daily smoking and in tobacco craving following cigarette cue exposure. Craving did not return to baseline values in the month that followed treatment discontinuation. This is the first study demonstrating that omega-3 PUFA supplementation reduces tobacco craving in regular smokers, compared to placebo treatment. Thus, omega-3 PUFAs may be of benefit in managing tobacco consumption. Further studies are needed on larger samples to explore the possible therapeutic implications for heavy cigarette smokers.