Docosahexaenoic Acid Ratio Research Articles

Effects of Vitamin C and E Supplementation on Growth, Fatty Acid Composition, Innate Immunity, and Antioxidant Capacity of Rainbow Trout (Oncorhynchus mykiss) Fed Oxidized Fish Oil

This 10-week feeding experiment examined the effects of supplementing vitamin C (VC) and E (VE) in oxidized oil diets on growth, fatty acid composition, blood physiological indicators, innate immunity, antioxidant capacity, and liver and intestine histology of rainbow trout (Oncorhynchus mykiss). Four diets were produced including a fresh fish oil containing diet (FFO diet), an oxidized fish oil containing diet (OFO diet), and OFO diet supplemented with 500 mg kg–1 VC and 400 mg kg–1 VE (OFO+C500+E400 diet) or 1,000 mg kg–1 VC and 800 mg kg–1 VE (OFO+C1000+E800 diet). Four hundred and twenty fish averaging 46.9 ± 0.32 g were stocked into 12 tanks and fed the diets twice a day to visual satiety. The results showed no significant effect of OFO or vitamins supplementation on growth, feed intake and feed utilization (P > 0.05). The groups that received OFO and OFO+C1000+E800 diets had significantly (P < 0.05) lower hepatosomatic indices than the other groups. Muscle fatty acid composition showed decreased proportion of 15:0, 16:0, 16:1n-7, 16:2n-4, 18:1n-5, 18:2n-6 (linoleic acid) and total saturated fatty acids in OFO group. Whereas higher percentages of 20:3n-6 and 20:3n-3 were found in OFO group. In addition, the highest ratio of docosahexaenoic acid (DHA, 22:6n-3) to eicosapentaenoic acid (EPA, 20:5n-3) was detected in OFO+C500+E400 group. The highest serum triglyceride concentration was recorded in the OFO group. Serum aspartate aminotransferase activity increased in OFO and OFO+C1000+E800 groups compared to OFO+C500+E400 group. Furthermore, significantly higher alkaline phosphatase activity in blood was found in OFO and OFO+C500+E400 groups. Significantly lower serum lysozyme, antiprotease, superoxide dismutase, and catalase activities were recorded in OFO group compared to FFO and OFO+C500+E400 groups, and an opposite trend was observed for malondialdehyde concentration. Muscle VC and VE concentrations, and liver and intestine histology remained unaffected. To conclude, feeding diet containing oxidized oil with peroxide value of 182 meq kg–1 with/without VC and VE supplementation did not influence growth and tissue VC and VE concentrations of rainbow trout. However, supplementing 500 mg kg–1 VC and 400 mg kg–1 VE reversed the adverse effects of OFO on non-specific immune response and antioxidant capacity.

Effects of feeding differentially enriched Artemia nauplii on the survival, growth, fatty acid composition, and air exposure stress response of Pacific cod (Gadus macrocephalus) larvae

The ability of enriched live food, such as Artemia, to improve the growth performance of Pacific cod (Gadus macrocephalus) larvae during larviculture has yet to be fully established. Thus, the effects of feeding differentially enriched Artemia to Pacific cod larvae were investigated here, specifically the effects on the survival, growth, fatty acid composition, and air exposure stress response of the larvae. Three different commercial Artemia enrichment emulsion oils were used: commercially available enrichment 1, 2, and 3, referred to as ER1, ER2, and ER3, respectively. Although ER2-treated Artemia contained the most eicosapentaenoic acid (EPA) and ER3-treated Artemia contained the most docosahexaenoic acid (DHA) and highly unsaturated fatty acid (HUFA), the ER1 enrichment improved overall survival, growth, and survival after air stress test to the greatest extent in larval Pacific cod. Furthermore, the levels of DHA and HUFA observed in larvae fed the ER1 diet were higher than the respective concentrations of these nutrients observed in larvae fed the other diets. Thus, under the experimental conditions applied in the present study, ER1 provided Artemia with DHA and EPA ratio of 4.1 for early feeding of Pacific cod larvae.

Effects of Dietary Protein and Lipid Levels on Growth, Body Composition, Blood Biochemistry, Antioxidant Capacity and Ammonia Excretion of European Grayling (Thymallus thymallus)

This study evaluated growth, body composition, antioxidant capacity, innate immunity and ammonia excretion of European grayling (Thymallus thymallus) fed diets containing different protein and lipid contents. Six diets were produced to contain 30, 40, or 50% protein and 10 or 20% lipid. Juvenile fish averaging 25.2 ± 0.28 g were stocked into eighteen 450-L circular tanks in a recirculating aquaculture system (RAS) and fed the test diets to satiation twice daily for 12 weeks. Fish weight gain (WG) was enhanced (P < 0.05) as dietary protein increased from 30% (229% WG) to 40% (262% WG) and plateaued thereafter. Enhancing protein and lipid content of diet led to reduced feed intake. Also, feed efficiency was improved by increasing dietary protein (by 40.8%) and lipid (by 16.5%) levels. An interaction of protein and lipid was found on whole-body lipid, and muscle lipid content increased as dietary lipid level increased. Muscle arachidonic acid (ARA), eicosapentaenoic acid (EPA, 20:5n-3) and total n-6 long-chain polyunsaturated fatty acids (LC-PUFA) contents enhanced by increasing dietary protein level. Moreover, increasing fat content of diet led to enhanced muscle linoleic acid, linolenic acid, total monounsaturated fatty acids (MUFA), total n-6, ratio of docosahexaenoic acid (DHA, 22:6n-3) to EPA and n-6/n-3. However, EPA, DHA, total n-6 LC-PUFA, total n-3, total n-3 LC-PUFA, and EPA/ARA ratio decreased at higher dietary lipid level. Serum triglyceride (TG) level and lactate dehydrogenase (LDH) activity decreased as dietary protein level increased. Increasing fat content of diet led to enhanced serum TG, cholesterol and glucose concentrations and reduced alanine aminotransferase, aspartate amino transferase and LDH activities. Serum malondialdehyde concentration was enhanced by increasing both dietary protein and lipid. Furthermore, serum myeloperoxidase activity was enhanced at higher dietary lipid level. Water ammonium nitrogen (NH4+-N) concentration was measured after 5 and 24 h of last feeding, and the results indicated the reduction of ammonia excretion as dietary lipid content increased. These findings suggest that 40% dietary protein can support optimal growth of juvenile European grayling reared in RAS and increasing lipid content from 10 to 20% can improve feed utilization and reduce ammonia excretion to the rearing water.

Consumption of Monounsaturated Fatty Acids Is Associated with Improved Cardiometabolic Outcomes in Four African-Origin Populations Spanning the Epidemiologic Transition.

Long-chain omega-3 PUFAs, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are of increasing interest because of their favorable effect on cardiometabolic risk. This study explores the association between omega 6 and 3 fatty acids intake and cardiometabolic risk in four African-origin populations spanning the epidemiological transition. Data are obtained from a cohort of 2500 adults aged 25–45 enrolled in the Modeling the Epidemiologic Transition Study (METS), from the US, Ghana, Jamaica, and the Seychelles. Dietary intake was measured using two 24 h recalls from the Nutrient Data System for Research (NDSR). The prevalence of cardiometabolic risk was analyzed by comparing the lowest and highest quartile of omega-3 (EPA+ DHA) consumption and by comparing participants who consumed a ratio of arachidonic acid (AA)/EPA + DHA and >4:1. Data were analyzed using multiple variable logistic regression adjusted for age, gender, activity, calorie intake, alcohol intake, and smoking status. The lowest quartile of EPA + DHA intake is associated with cardiometabolic risk 2.16 (1.45, 3.2), inflammation 1.59 (1.17, 2.16), and obesity 2.06 (1.50, 2.82). Additionally, consuming an AA/EPA + DHA ratio of >4:1 is also associated with cardiometabolic risk 1.80 (1.24, 2.60), inflammation 1.47 (1.06, 2.03), and obesity 1.72 (1.25, 2.39). Our findings corroborate previous research supporting a beneficial role for monounsaturated fatty acids in reducing cardiometabolic risk.

Mfsd2a overexpression alleviates vascular dysfunction in diabetic retinopathy

Diabetic retinopathy (DR) is one of the common complications in diabetic patients. Nowadays, VEGF pathway is subject to extensive research. However, about 27% of the patients have a poor visual outcome, with 50% still having edema after two years’ treatment of diabetic macular edema (DME) with ranibizumab. Docosahexaenoic acid (DHA), the primary ω-3 long-chain polyunsaturated fatty acid (LC-PUFA), reduces abnormal neovascularization and alleviates neovascular eye diseases. A study reported that fish oil reduced the incidence of retinopathy of prematurity (ROP) by about 27.5% in preterm infants. Although ω-3 LC-PUFAs protects against pathological retinal neovascularization, the treatment effectiveness is low. It is interesting to investigate why DHA therapy fails in some patients. In human vitreous humor samples, we found that the ratio of DHA and DHA-derived metabolites to total fatty acids was higher in vitreous humor from DR patients than that from macular hole patients; however, the ratio of DHA metabolites to DHA and DHA-derived metabolites was lower in the diabetic vitreous humor. The expression of Mfsd2a, the LPC-DHA transporter, was reduced in the oxygen-induced retinopathy (OIR) model and streptozotocin (STZ) model. In vitro, Mfsd2a overexpression inhibited endothelial cell proliferation, migration and vesicular transcytosis. Moreover, Mfsd2a overexpression in combination with the DHA diet obviously reduced abnormal retinal neovascularization and vascular leakage, which is more effective than Mfsd2a overexpression alone. These results suggest that DHA therapy failure in some DR patients is linked to low expression of Mfsd2a, and the combination of Mfsd2a overexpression and DHA therapy may be an effective treatment.

High trophic plasticity in the mixotrophic Mastigias papua-Symbiodiniaceae holobiont: implications for the ecology of zooxanthellate jellyfishes

The trophic ecology of mixotrophic, zooxanthellate jellyfishes potentially spans a wide spectrum between autotrophy and heterotrophy. However, their degree of trophic plasticity along this spectrum is not well known. To better characterize their trophic ecology, we sampled the zooxanthellate medusa Mastigias papua in contrasting environments and sizes in Palau (Micronesia). We characterized their trophic ecology using isotopic (bulk δ13C and δ15N), elemental (C:N ratios), and fatty acid compositions. The different trophic indicators were correlated or anti-correlated as expected (Pearson’s correlation coefficient, rP > 0.5 or < -0.5 in 91.1% of cases, p < 0.05), indicating good agreement. The sampled M. papua were ordered in a trophic spectrum between autotrophy and heterotrophy (supported by decreasing δ13C, C:N, proportion of neutral lipid fatty acids (NLFA:TLFA), n-3:n-6 and increasing δ15N, eicosapentaenoic acid to docosahexaenoic acid ratio (EPA:DHA)). This trophic spectrum was mostly driven by sampling location with little influence of medusa size. Moreover, previous observations have shown that in a given location, the trophic ecology of M. papua can change over time. Thus, the positions on the trophic spectrum of the populations sampled here are not fixed, suggesting high trophic plasticity in M. papua. The heterotrophic end of the trophic spectrum was occupied by non-symbiotic M. papua, whereas the literature indicates that the autotrophic end of the spectrum corresponds to dominant autotrophy, where more than 100% of the carbon requirement is obtained by photosynthesis. Such high trophic plasticity has critical implications for the trophic ecology and blooming ability of zooxanthellate jellyfishes.

Fish Oil Enriched in EPA, but Not in DHA, Reverses the Metabolic Syndrome and Adipocyte Dysfunction Induced by a High-Fat Diet

This study aimed to investigate the effects of two commercially available fish oils (FOs) containing different proportions of two omega-3 fatty acids (FA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on the metabolic and endocrine dysfunctions of white adipose tissue resulting from obesity. Male C57BL/6J mice, 8 weeks old, received a control or high-fat diet (CO and HF groups, with 9% and 59% energy from fat, respectively) for 8 weeks. The next 8 weeks, the HF group was subdivided into HF, HF+FO/E (HF+5:1 EPA:DHA), and HF+FO/D (HF+5:1 DHA:EPA). Supplementation was performed by gavage, three times a week. All groups that received the HF diet had lower food and caloric intake, but a higher fat intake, body weight (BW) gain, glucose intolerance, and a significant increase in inguinal (ING), retroperitoneal (RP), and epididymal (EPI) adipose tissues when compared to the CO group. Additionally, HF and HF+FO/D groups showed insulin resistance, adipocyte hypertrophy, increased lipolysis and secretion of TNF-α, resistin and IL-10 adipokines by ING and RP adipocytes, and adiponectin only by the HF+FO/D group in ING adipocytes. All of these effects were completely reversed in the HF+FO/E group, which also showed partial reversion in BW gain and glucose intolerance. Both the HF+FO/E and HF+FO/D groups showed a reduction in ING and RP adipose depots when compared to the HF group, but only HF+FO/E in the EPI depot. HF+FO/E, but not HF+FO/D, was able to prevent the changes triggered by obesity in TNF-α, Il-10, and resistin secretion in ING and RP depots. These results strongly suggest that different EPA:DHA ratios have different impacts on the adipose tissue metabolism, FO being rich in EPA, but not in DHA, and effective in reversing the changes induced by obesity.

A High-Fat Diet Induces Lower Systemic Inflammation than a High-Carbohydrate Diet in Mice.

Background: We previously established that male Swiss mice (Mus musculus) receiving a high-fat diet (HFD) during 8 weeks exhibit similar caloric ingestion and body weight (grams) compared with mice fed a high-carbohydrate diet (HCD). HFD mice exhibit a lower inflammatory state than an HCD in the liver, skeletal muscle, and brain. In addition, we demonstrated that HFD and HCD modulated fatty acids (FA) composition in these tissues. In this study, our objective was to compare HFD mice and HCD mice in terms of systemic inflammation. Methods: Saturated FA (SFA), monounsaturated FA, omega-6 polyunsaturated FA (n-6 PUFA), and n-3 PUFA were evaluated at the time points 0, 1, 7, 14, 28, and 56 days after starting the administration of the diets. We investigated n-6 PUFA:n-3 PUFA, SFA:n-3 PUFA, palmitic acid:α-linolenic acid (ALA), and myristic acid:docosahexaenoic acid (DHA) ratios as potential serum biomarkers of systemic inflammation. We also measured the serum levels of basic fibroblast growth factor, granulocyte-macrophage colony-stimulating factor (GM-CSF), inducible protein 10 (IP-10), interferon gamma (IFN-γ), interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-13, IL-17, macrophage inflammatory protein-1α (MIP-1-α), monocyte chemotactic protein 1 (MCP-1), monokine induced by IFN-γ (MIG), and tumor necrosis factor α (TNF-α). Results: The HFD group had lower (P < 0.05) n-6 PUFA:n-3 PUFA, palmitic acid:ALA, myristic acid:DHA ratios, and lower plasma levels of proinflammatory cytokines (IFN-γ, MIG, GM-CSF, and IL-6). Conclusion: The HFD mice showed lower systemic inflammation compared with a caloric ingestion-body weight-matched control HCD mice.

The ratio of eicosapentaenoic acid to docosahexaenoic acid as a modulator for the cardio-metabolic effects of omega-3 supplements: A meta-regression of randomized clinical trials

BackgroundA large number of studies have demonstrated the effects of omega- 3 supplements containing mixtures of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), known to favorably affect many modifiable risk factors of coronary heart disease (CHD). These studies have used diverse ratios and doses of EPA and DHA. However, it is not known whether the ratio of EPA to DHA in omega-3 supplements affect their efficacy as modulators for cardiovascular risk factors. This meta-regression aimed to investigate the effect of different ratios of EPA to DHA on risk factors associated with CHD including lipid profile, blood pressure, heart rate, and inflammation. MethodA regression analysis was carried out on 92 clinical trials with acceptable quality (Jadad score ≥ 3) that were previously identified from two databases (PubMed and Cochrane Library). ResultsData from studies that met the inclusion criteria for this analysis showed that the ratio of EPA to DHA was not associated with lipid profile, diastolic blood pressure, or heart rate. With all studies, the ratio of EPA to DHA was associated with C-reactive protein (CRP) (β = -1.3121 (95 % CI: -1.6610 to -0.9543), that is, the higher the EPA to DHA ratio, the greater the reduction. Using only studies that supplied EPA and DHA in the range of 2 g–6 g, the ratio of EPA to DHA was also associated with CRP (β = -2.10429 and 95 % CI: -3.89963 to -0.30895); that is, an even more pronounced reduction in CRP with a higher EPA to DHA ratio. Systolic blood pressure was only associated with an increasing EPA to DHA ratio in the 2 g–6 g range (β = 5.47129 and 95 % CI: 0.40677–10.53580), that is, a higher EPA to DHA ratio within this dose range, the greater the increase in SBP. ConclusionCurrent data suggest that the EPA to DHA ratio only correlates to the modulation of CRP by omega-3 supplementation of EPA and DHA, and SBP in studies that supplemented EPA and DHA in the range of 2 g–6 g, shedding light on potential differential effects of EPA vs. DHA on inflammation and systolic blood pressure.

Oxidative stability of eicosapentaenoic acid and docosahexaenoic acid in krill oil microencapsulated by spray drying

Krill oil (KO) is rich in polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which have many health benefits. However, the oil is unstable owing to its high degree of unsaturation. The oil was microencapsulated using maltodextrin (MD) with a dextrose equivalent of 19 as a wall material to improve its stability. A saponin (Quillayanin) and sodium caseinate were also used as emulsifiers, and rosemary oil (RO) extract or sodium ascorbate was used as an antioxidant. The microencapsulated KO samples were stored at 25, 50, or 70°C to examine the stability of EPA and DHA in the KO. The surface-oil ratios of the KO encapsulated powders by spray-drying were from 4.2 wt% to 52.2 wt% and depended significantly on the reconstituted oil-droplet diameter, 0.48 µm to 9.29 µm. For the microcapsules prepared from emulsions with smaller oil droplets, the surface-oil ratios of EPA and DHA were higher, but the fatty acids were less stable at 50 and 70°C. On the other hand, both EPA and DHA in the microcapsules prepared from emulsions with small oil droplets with 3 wt% Quillayanin, 1 wt% RO, and 2 wt% sodium ascorbate were stable at 25°C. The chemical compensation held for the destabilization of both EPA and DHA in microencapsulated KO.

Impacts of dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) level and ratio on the growth, fatty acids composition and hepatic-antioxidant status of largemouth bass (Micropterus salmoides)

A ten-week feeding trial was conducted to evaluate largemouth bass (Micropterus salmoides, LMB) responses to supplemental eicosapentaenoic acid (EPA)- and docosahexaenoic acid (DHA)-rich oils at different inclusion levels and ratios. For this purpose, eight experimental diets were formulated to contain 42% crude protein and12% lipid. Two diets were formulated to be n-3 fatty acid (FA) and EPA/DHA depleted and served as negative controls for n-3 FA or EPA + DHA, respectively. Two additional sets of three diets were designed to contain 1 or 2% EPA + DHA and three different EPA:DHA ratios (20:80, 50:50, and 80:20). Each diet was fed to triplicate groups of 15 feed-trained juvenile LMB (13.8 ± 0.2 g initial weight) stocked in 110-L glass aquaria operating as a recirculating aquaculture system. At the end of the feeding trial, the production performance of LMB fed EPA + DHA supplemented diets was unaffected by EPA + DHA levels and ratios. However, LMB fed diets with either 1 or 2% EPA + DHA displayed higher weight gain and feed efficiency compared to those fed un-supplemented diets. HSI was lower groups fed n-3 FA depleted compared to 2% EPA + DHA-fed groups. No significant differences were detected for whole-body proximate composition of LMB; while whole-body EPA and DHA concentrations were significantly affected by diet. Liver antioxidant enzyme activities were unaffected by the dietary supplementation of 1 or 2% EPA + DHA, but liver superoxide dismutase activity was significantly higher in fish fed EPA/DHA depleted diet relative fish fed the n-3 FA depleted and 1% EPA + DHA diets. On the contrary, significantly lower malondialdehyde concentration was observed in the liver of LMB fed the latter relative to fish fed the former diet. Based on the overall findings, LMB appears to be able to synthesize EPA and DHA from linolenic acid to meet physiological needs for adequate production performance and health. Nevertheless, our findings also indicate that both weight gain and feed efficiency, as well as whole-body concentrations of EPA and DHA can be enhanced in LMB by the dietary provision of around 1% EPA + DHA.

Effect of APOE Genotype on Plasma Docosahexaenoic Acid (DHA), Eicosapentaenoic Acid, Arachidonic Acid, and Hippocampal Volume in the Alzheimer's Disease Cooperative Study-Sponsored DHA Clinical Trial.

Docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (AA) play key roles in several metabolic processes relevant to Alzheimer's disease (AD) pathogenesis and neuroinflammation. Carrying the APOEɛ4 allele (APOE4) accelerates omega-3 polyunsaturated fatty acid (PUFA) oxidation. In a pre-planned subgroup analysis of the Alzheimer's Disease Cooperative Study-sponsored DHA clinical trial, APOE4 carriers with mild probable AD had no improvements in cognitive outcomes compared to placebo, while APOE 4 non-carriers showed a benefit from DHA supplementation. We sought to clarify the effect of APOEɛ4/ɛ4 on both the ratio of plasma DHA and EPA to AA, and on hippocampal volumes after DHA supplementation. Plasma fatty acids and APOE genotype were obtained in 275 participants randomized to 18 months of DHA supplementation or placebo. A subset of these participants completed brain MRI imaging (n = 86) and lumbar punctures (n = 53). After the intervention, DHA-treated APOEɛ3/ɛ3 and APOEɛ2/ɛ3 carriers demonstrated significantly greater increase in plasma DHA/AA compared to ɛ4/ɛ4 carriers. APOEɛ2/ɛ3 had a greater increase in plasma EPA/AA and less decline in left and right hippocampal volumes compared to compared to ɛ4/ɛ4 carriers. The change in plasma and cerebrospinal fluid DHA/AA was strongly correlated. Greater baseline and increase in plasma EPA/AA was associated with a lower decrease in the right hippocampal volume, but only in APOE 4 non-carriers. The lower increase in plasma DHA/AA and EPA/AA in APOEɛ4/ɛ4 carriers after DHA supplementation reduces brain delivery and affects the efficacy of DHA supplementation.

High omega arachidonic acid/docosahexaenoic acid ratio induces mitochondrial dysfunction and altered lipid metabolism in human hepatoma cells.

BACKGROUNDNon-alcoholic fatty liver disease (NAFLD) is a common cause of liver disease worldwide and is a growing epidemic. A high ratio of omega-6 fatty acids to omega-3 fatty acids in the diet has been implicated in the development of NAFLD. However, the inflicted cellular pathology remains unknown. A high ratio may promote lipogenic pathways and contribute to reactive oxygen species (ROS)-mediated damage, perhaps leading to mitochondrial dysfunction. Therefore, these parameters were investigated to understand their contribution to NAFLD development.AIMTo examine the effect of increasing ratios of omega-6:3 fatty acids on mitochondrial function and lipid metabolism mediators.METHODSHepG2-derived VL-17A cells were treated with normal (1:1, 4:1) and high (15:1, 25:1) ratios of omega-6: omega-3 fatty acids [arachidonic acid (AA): docosahexaenoic acid (DHA)] at various time points. Mitochondrial activity and function were examined via MTT assay and Seahorse XF24 analyzer, respectively. Triglyceride accumulation was determined by using EnzyChrom™ and levels of ROS were measured by fluorescence intensity. Protein expression of the mediators of lipogenic, lipolytic and endocannabinoid pathways was assessed by Western blotting.RESULTSHigh AA:DHA ratio decreased mitochondrial activity (P < 0.01; up to 80%) and promoted intracellular triglyceride accumulation (P < 0.05; 40%-70%). Mechanistically, it altered the mediators of lipid metabolism; increased the expression of stearoyl-CoA desaturase (P < 0.05; 22%-35%), decreased the expression of peroxisome proliferator-activated receptor-alpha (P < 0.05; 30%-40%) and increased the expression of cannabinoid receptor 1 (P < 0.05; 31%). Furthermore, the high ratio increased ROS production (P < 0.01; 74%-115%) and reduced mitochondrial respiratory functions such as basal and maximal respiration, ATP production, spare respiratory capacity and proton leak (P < 0.01; 35%-68%).CONCLUSIONHigh AA:DHA ratio induced triglyceride accumulation, increased oxidative stress and disrupted mitochondrial functions. Stimulation of lipogenic and steroidal transcription factors may partly mediate these effects and contribute to NAFLD development.

Child Head Circumference and Placental MFSD2a Expression Are Associated to the Level of MFSD2a in Maternal Blood During Pregnancy.

Gestational diabetes mellitus (GDM) is a world-wide health challenge, which prevalence is expected to increase in parallel to the epidemic of obesity. Children born from GDM mothers have lower levels of docosahexaenoic acid (DHA) in cord blood, which might influence their neurodevelopment. Recently, the membrane transporter Major Family Super Domain 2a (MFSD2a) was associated with the selective transportation of DHA as lysophospholipids. The expression of the DHA membrane transporter MFSD2a is lower in GDM placentas, which could affect materno-fetal DHA transport. Humans with homozygous inactivating mutations in the MFSD2a gene present severe microcephaly and intellectual impairments. Herein, we intended to identify early blood biomarkers that may be of use during pregnancy to monitor the offspring development and the adequate nutritional interventions, such as nutritional supplementation, that may be selected to improve it. We evaluated MFSD2a expression in maternal blood at the third trimester of pregnancy, and its potential relationship with the expression of placental MFSD2a at delivery and child outcomes. Three groups of pregnant women were recruited: 25 controls, 23 GDM with dietary treatment, and 20 GDM with insulin treatment. Maternal and neonatal anthropometric and biochemical parameters were evaluated. MFSD2a was analyzed in placenta, blood and serum. MFSD2a protein expression in maternal blood was significantly lower in GDM groups and correlated with placental MFSD2a and Z-score neonatal head circumference during the first 6 months of life. The cord/maternal serum ratio of DHA, a solid indicator of materno-fetal DHA transport, was reduced in GDM groups and correlated with MFSD2a in maternal blood at the third trimester and in placenta at delivery. This indicates that altered MFSD2a levels in maternal blood during pregnancy might influence placental nutrient transport and fetal neurodevelopment. Furthermore, MFSD2a levels in maternal blood on the third trimester were inversely correlated to DHA in maternal serum lyso-PL. Thus, the level of MFSD2a in maternal blood could be used as a potential biomarker for the early detection of disturbances of MFSD2a expression during pregnancy and the subsequent consequences for the neurodevelopment of the child, as well as it may help to choose the optimal treatment approach for the affected subjects.

Plasma Oxidative Status in Preterm Infants Receiving LCPUFA Supplementation: A Pilot Study

After birth, preterm infants are deficient in arachidonic acid (ARA), docosahexaenoic acid (DHA), and antioxidants, increasing their risk of oxidative stress-related pathologies. The principal aim was to evaluate if supplementation with long-chain polyunsaturated fatty acids (LCPUFAs) improves antioxidant defenses. In total, 21 preterm infants were supplemented with ARA and DHA in a 2:1 ratio (ARA:DHA-S) or with medium-chain triglycerides (MCT-S). Plasma n-3 and n-6 LCPUFAs were measured at birth, postnatal day 28, and 36 weeks of postmenstrual age (36 WPA) by gas chromatography–mass spectroscopy. Plasma antioxidants (glutathione (GSH), catalase, and thiols) and oxidative damage biomarkers (malondialdehyde (MDA), carbonyls) were analyzed at the same time points by spectrophotometry, and scores of antioxidant status (Antiox-S) and oxidative damage (Proxy-S) were calculated. At 36 WPA, linoleic acid (LA) and dihomo-γ-linolenic acid (DGLA) were decreased in ARA:DHA-S compared to the MCT-S group (LA: ARA:DHA-S = 18.54 ± 1.68, MCT-S = 22.80 ± 1.41; p = 0.018; DGLA: ARA:DHA-S = 1.68 ± 0.38, MCT-S = 2.32 ± 0.58; p = 0.018). Furthermore, α-linolenic acid (ALA) was increased in ARA:DHA-S (ARA:DHA-S = 0.52 ± 0.33, MCT-S = 0.22 ± 0.10; p = 0.018). Additionally, LA:DHA ratio was decreased in the ARA:DHA-S compared to control group (ARA:DHA-S = 6.26 ± 2.35, MCT-S = 8.21 ± 2.65; p = 0.045). By the end of supplementation (36 WPA), catalase, thiol groups, and Antiox-S were significantly higher in neonates receiving ARA:DHA-S compared to those receiving MCT-S, with no differences in oxidative stress biomarkers. In conclusion, ARA:DHA supplementation in preterm neonates resulted in an overall improvement in antioxidant to oxidant balance and a decrease in early fatty acid precursors of the n-6 relative to the n-3 pathway. These effects may reduce oxidative stress and inflammation.

Comparison of Fatty Acid Compositions of Commercial Fish and Fish By-Products Oils Used in Fish Feed Industry in Turkey

Fats have a function in transmitting the necessary fatty acids to fish as well as being an energy source in fish nutrition. In particular, high-chain unsaturated fatty acids are needed for feeding saltwater fish. In this study, the fatty acid composition of fish oils obtained from some whole-body fish and fish by-products used in the fish-feed industry in Turkey was determined and compared with each other. Accordingly, SFA (Saturated fatty acids) ratios were in the range of 15.57-33.38% in the oils obtained from the whole-body fish and in the range of 16.3-31.89% in the oils from fish by-products; MUFA (Monounsaturated fatty acids) ratios were in the range of 24-38.69% in the oils obtained from the whole-body fish and in the range of 25.81-47.57% in the oils from fish by-products; PUFA (Polyunsaturated fatty acids) ratios were in the range of 31-36.73% in the oils obtained from the whole-body fish and in the range of 33.54-36.78% in the oils from fish by-products. Given DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) ratios which are among the most important PUFAs for nutrition, it was determined that DHA ratios were in the range of 14.08-19.10% in the oils obtained from the whole-body fish and in the range of 3.55-15.28% in the oils from fish by-products, whereas EPA ratios were in the range of 8-9.89% in the oils obtained from the whole-body fish and in the range of 2.63-15.28% in the oils from fish by-products.

GWAS identifies genetic variants associated with omega-3 fatty acid composition of Atlantic salmon fillets

The objective of this study was to identify genetic variants associated with long-chain omega-3 fatty acid content in Atlantic salmon muscle, in order to identify genes underlying the genetic variation in these traits, by performing a genome-wide association study.Fatty acid composition, including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) content and the ratios DHA/DPA (docosapentaenoic acid) and DHA/ALA (α-linolenic acid) of skeletal muscle was determined in 642 Atlantic salmon individuals from the Salmobreed broodstock program. Further, a 57 K single-nucleotide polymorphism (SNP) array was used to genotype the 642 individuals to search for SNPs associated with skeletal muscle content of individual omega-3 fatty acids as well as ratios between fatty acids, using a mixed model approach. We identified markers showing a significant association with the ratio of DHA to DPA located on chromosome 19, close to the candidate gene elovl2, which is directly involved in the conversion of DPA to DHA. The results further suggested that genetic variation affecting fillet EPA and DHA content is present on Atlantic salmon chromosome 21, as the GWAS analysis of EPA, DHA and DHA/ALA ratio all pointed to this chromosome. No known genes of direct relevance to the omega-3 bioconversion pathway were found here. We discuss the relevance of other interesting genes related to lipid metabolism and health located in this region.

Early Enteral Administration of a Complex Lipid Emulsion Supplement Prevents Postnatal Deficits in Docosahexaenoic and Arachidonic Acids and Increases Tissue Accretion of Lipophilic Nutrients in Preterm Piglets.

Preterm delivery and current nutrition strategies result in deficiencies of critical long-chain fatty acids (FAs) and lipophilic nutrients, increasing the risk of preterm morbidities. We sought to determine the efficacy of preventing postnatal deficits in FAs and lipophilic nutrients using an enteral concentrated lipid supplement in preterm piglets. Preterm piglets were fed a baseline diet devoid of arachidonic acid (AA) and docosahexaenoic acid (DHA) and randomized to enteral supplementation as follows: (1) Intralipid (IL), (2) complex lipid supplement 1 (CLS1) with an AA:DHA ratio of 0.25, or (3) CLS2 with an AA:DHA ratio of 1.2. On day 8, plasma and tissue levels of FAs and lipophilic nutrients were measured and ileum histology performed. Plasma DHA levels decreased in the IL group by day 2. In contrast, DHA increased by day 2 compared with birth levels in both CLS1 and CLS2 groups. The IL and CLS1 groups demonstrated a continued decline in AA levels during the 8-day protocol, whereas AA levels in the CLS2 group on day 8 were comparable to birth levels. Preserving AA levels in the CLS2 group was associated with greater ileal villus height and muscular layer thickness. Lipophilic nutrients were effectively absorbed in plasma and tissues. Enteral administration of CLS1 and CLS2 demonstrated similar increases in DHA levels compared with birth levels. Only CLS2 maintained AA birth levels. Providing a concentrated complex lipid emulsion with an AA:DHA ratio > 1 is important in preventing postnatal AA deficits.

Isolation, Characterization and Biotechnological Potentials of Thraustochytrids from Icelandic Waters.

The following study reports on the first thraustochytrid isolates identified from Iceland. They were collected from three different locations off the northern coast of the country (Location A, Skagaströnd; Location B, Hveravík; and Location C, Eyjafjörður). Using 18S rDNA sequence analysis, isolates from Locations A and B were identified within the Thraustochytrium kinnei species while other isolates within the Sicyoidochytrium minutum species when compared to other known strains. Cells isolated from Locations A ( g/L) and B ( g/L) produced more biomass than the ones isolated from Location C ( g/L). This study offers the first-time examination of the utility of byproducts from fisheries as a nitrogen source in media formulation for thraustochytrids. Experiments showed that isolates produced more biomass (per unit of substrate) when cultured on nitrogen of marine ( g/L) as compared to of commercial origin ( g/L). Glycerol ( g/L) was a better carbon source than glucose ( g/L) in growth studies. Fatty acid (FA) profiles showed that the isolates from Location C (S. minutum) had low ratios of monounsaturated () and omega-6 () FAs. However, the isolates also had high ratios of docosahexaenoic acid (DHA; ) and total omega-3 FAs (), indicating that they could serve as a source of marine oils for human consumption and in aquaculture feeds. The T. kinnei isolates from Location A could be used in biodiesel production due to their high ratios of monounsaturated () long chain () FAs.

Relationships between Atherosclerosis and Plasma Antioxidant Micronutrients or Red Blood Cell Polyunsaturated Fatty Acids in People Living with HIV.

Background: People living with human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS) (PLWH) are at an increased risk of cardiovascular disease. Diet-related factors may contribute. The aim of this pilot study was to determine, in PLWH, the relationship between atherosclerosis assessed by carotid intima-media thickness (CIMT) and (A) plasma antioxidant micronutrients and oxidative stress or (B) red blood cell polyunsaturated fatty acids (RBC PUFA), particularly long chain omega-3 polyunsaturated fatty acids (n-3 PUFA). Methods: (A) In a cross-sectional study, subjects had CIMT evaluated by high resolution carotid artery ultrasound. Plasma was collected for vitamin C, measured by spectrophotometry; and alpha- and gamma-tocopherol, retinol, and malondialdehyde—a marker of oxidative stress—using high pressure liquid chromatography and fluorescence spectrophotometry. (B) In a prospective cohort study, other subjects had RBC PUFA measured at baseline, using gas chromatography, and CIMT assessed at baseline and repeated after 2 years. Clinical data was also collected. Results: (A) 91 PLWH participated. Only alpha- and gamma-tocopherol levels were positively correlated with CIMT. In a multivariate analysis, age and systolic blood pressure were significantly associated with CIMT with gamma-tocopherol near significance (p = 0.053). (B) 69 PLWH participated. At baseline, docosahexaenoic acid (n-3 PUFA) and the ratio of docosahexaenoic acid to arachidonic acid (n-6 PUFA) were significantly and negatively correlated with CIMT. However, a multivariate analysis failed to detect a significant relationship either at baseline or 2 years after. Conclusion: In addition to age and systolic blood pressure, atherosclerosis assessed by CIMT might be associated with higher serum gamma-tocopherol levels. There was a non-significant association between CIMT and RBC n-3 PUFA or the ratio of n-3 to n-6 PUFA.