Evolutionary aspects of diet: the omega-6/omega-3 ratio and the brain

Testing the Effects of Dietary Seafood Consumption on Depressive Symptoms

This chapter presents a protocol for assessing the effects dietary seafood consumption on depressive symptoms. We designed a cross-sectional study of 206 participants recruited in two Torres Strait Island communities. Depressive symptoms were assessed using the adapted Patient Health Questionnaire-9 (aPHQ-9), diet was analyzed with a structured questionnaire, omega-3 and omega-6 fatty acid concentrations were measured via a capillary dried blood spot system, and plasma levels of triglycerides and cholesterol were measured by gas-phase chromatography. Finally, we tested the relationship between seafood consumption, blood lipid concentrations, and depression scores using independent samples t-tests and a logistic and quantile regression model.

Causal relationships between genetically determined metabolites and human intelligence: a Mendelian randomization study

Intelligence predicts important life and health outcomes, but the biological mechanisms underlying differences in intelligence are not yet understood. The use of genetically determined metabotypes (GDMs) to understand the role of genetic and environmental factors, and their interactions, in human complex traits has been recently proposed. However, this strategy has not been applied to human intelligence. Here we implemented a two-sample Mendelian randomization (MR) analysis using GDMs to assess the causal relationships between genetically determined metabolites and human intelligence. The standard inverse-variance weighted (IVW) method was used for the primary MR analysis and three additional MR methods (MR-Egger, weighted median, and MR-PRESSO) were used for sensitivity analyses. Using 25 genetic variants as instrumental variables (IVs), our study found that 5-oxoproline was associated with better performance in human intelligence tests (P_IVW = 9.25 × 10^-5). The causal relationship was robust when sensitivity analyses were applied (P_MR-Egger = 0.0001, P_{Weighted median} = 6.29 × 10^-6, P_MR-PRESSO = 0.0007), and repeated analysis yielded consistent result (P_IVW = 0.0087). Similarly, also dihomo-linoleate (20:2n6) and p-acetamidophenylglucuronide showed robust association with intelligence. Our study provides novel insight by integrating genomics and metabolomics to estimate causal effects of genetically determined metabolites on human intelligence, which help to understanding of the biological mechanisms related to human intelligence.

The placental lipidome of maternal antenatal depression predicts socio-emotional problems in the offspring

While maternal mental health strongly influences neurodevelopment and health in the offspring, little is known about the determinants of inter-individual variation in the mental health of mothers. Likewise, the in utero biological pathways by which variation in maternal mental health affects offspring development remain to be defined. Previous studies implicate lipids, consistent with a known influence on cognitive and emotional function, but the relevance for maternal mental health and offspring neurodevelopment is unclear. This study characterizes the placental and circulatory lipids in antenatal depression, as well as socio-emotional outcomes in the offspring. Targeted liquid chromatography-mass spectrometry covering 470 lipid species was performed on placenta from 186 women with low (n = 70) or high (n = 116) levels of antenatal depressive symptoms assessed using the Edinburgh Postnatal Depression Scale at 26 weeks' gestation. Child socio-emotional outcomes were assessed from the Child Behavior Check List (CBCL) at 48 months. Seventeen placental lipid species showed an inverse association with antenatal EPDS scores. Specifically, lower levels of phospholipids containing LC-PUFAs: omega-3 docosapentaenoic acid (DPA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and omega-6 arachidonic acid (AA) were significantly associated with depressive symptoms. Additional measurement of LC-PUFA in antenatal plasma samples at mid-gestation confirmed the reduced circulation of these specific fatty acids in mothers. Reduced concentration of the placental phospholipids also predicted poorer socio-emotional outcomes in the offspring. This study provides new insights into the role of the materno-fetal lipid cross-talk as a mechanism linking maternal mental health to that of the offspring. These findings show the potential utility of nutritional approaches among pregnant women with depressive symptoms to reduce offspring risk for later socio-emotional problems.

Lipoprotein Lipase Regulates Microglial Lipid Droplet Accumulation

Microglia become increasingly dysfunctional with aging and contribute to the onset of neurodegenerative disease (NDs) through defective phagocytosis, attenuated cholesterol efflux, and excessive secretion of pro-inflammatory cytokines. Dysfunctional microglia also accumulate lipid droplets (LDs); however, the mechanism underlying increased LD load is unknown. We have previously shown that microglia lacking lipoprotein lipase (LPL KD) are polarized to a pro-inflammatory state and have impaired lipid uptake and reduced fatty acid oxidation (FAO). Here, we also show that LPL KD microglia show excessive accumulation of LD-like structures. Moreover, LPL KD microglia display a pro-inflammatory lipidomic profile, increased cholesterol ester (CE) content, and reduced cholesterol efflux at baseline. We also show reduced expression of genes within the canonical cholesterol efflux pathway. Importantly, PPAR agonists (rosiglitazone and bezafibrate) rescued the LD-associated phenotype in LPL KD microglia. These data suggest that microglial-LPL is associated with lipid uptake, which may drive PPAR signaling and cholesterol efflux to prevent inflammatory lipid distribution and LD accumulation. Moreover, PPAR agonists can reverse LD accumulation, and therefore may be beneficial in aging and in the treatment of NDs.

Nutritional consequences of breeding away from riparian habitats in Bank Swallows: new evidence from multiple endogenous markers

The Bank Swallow (Riparia riparia), a threatened species in Canada, breeds primarily in banks at lakeshores and rivers and in artificial (typically inland) aggregate mining pits. Inland pits may be ecological traps for this species, but relative dietary trade-offs between these two nesting habitats have not been investigated. The availability of aquatic emergent insects at lakeshores may have associated nutritional benefits for growing nestlings due to increased omega-3 fatty acids (FAs) in prey. We compared the diets of juvenile swallows from lakeshore and inland pit sites using assays of stable isotope values (δ¹³C, δ¹⁵N, δ²H) of feathers, faecal DNA metabarcoding and blood plasma FAs. Colony proximity to Lake Erie influenced the use of aquatic versus terrestrial insects by Bank Swallow adults and juveniles. Feather δ²H was particularly useful as a tracer of aquatic emergent versus terrestrial prey, and inland juveniles had feathers enriched in ²H, reflective of diets composed of fewer aquatic emergent insects. DNA metabarcoding of juvenile and adult faecal material indicated that lakeshore birds consumed more aquatic-emergent chironomids than inland birds. Lakeshore juveniles had elevated plasma omega-3 eicosapentaenoic acid levels compared with inland pit-breeding birds. We discuss the need to consider 'nutritional landscapes' and the importance of this concept in conservation of declining species and populations.

Maternal DHA supplementation influences sex-specific disruption of placental gene expression following early prenatal stress

Early life adversity is widely recognized as a key risk factor for early developmental perturbations and contributes to the presentation of neuropsychiatric disorders in adulthood. Neurodevelopmental disorders exhibit a strong sex bias in susceptibility, presentation, onset, and severity, although the underlying mechanisms conferring vulnerability are not well understood. Environmental perturbations during pregnancy, such as malnutrition or stress, have been associated with sex-specific reprogramming that contribute to increased disease risk in adulthood, whereby stress and nutritional insufficiency may be additive and further exacerbate poor offspring outcomes. To determine whether maternal supplementation of docosahexanoic acid (DHA) exerts an effect on offspring outcome following exposure to early prenatal stress (EPS), dams were fed a purified 10:1 omega-6/omega-3 diet supplemented with either 1.0% preformed DHA/kg feed weight (DHA-enriched) or no additional DHA (denoted as the control diet, CTL). Dams were administered chronic variable stress during the first week of pregnancy (embryonic day, E0.5–7.5), and developmental milestones were assessed at E 12.5. Exposure to early prenatal stress (EPS) decreased placenta and embryo weight in males, but not females, exposed to the CTL diet. DHA enrichment reversed the sex-specific decrease in placenta and embryo weight following EPS. Early prenatal exposure upregulated expression of genes associated with oxygen and nutrient transport, including hypoxia inducible factor 3α (HIF3α), peroxisome proliferator-activated receptor alpha (PPARα), and insulin-like growth binding factor 1 (IGFBP1), in the placenta of CTL diet males exposed to EPS. DHA enrichment in EPS-exposed animals abrogated the male-specific upregulation of PPARα, HIF3α, and IGFBP1. Taken together, these studies suggest that maternal dietary DHA enrichment may buffer against maternal stress programming of sex-specific outcomes during early development.

The influence of fish consumption on serum n-3 polyunsaturated fatty acid (PUFA) concentrations in women of childbearing age: a randomised controlled trial (the iFish Study)

PURPOSE

Long-chain polyunsaturated fatty acids (LCPUFA) can be synthesised endogenously from linoleic acid (LA) and α-linolenic acid (ALA) in a pathway involving the fatty acid desaturase (FADS) genes. Endogenous synthesis is inefficient; therefore, dietary intake of preformed LCPUFA from their richest source of fish is preferred. This study investigated the effect of fish consumption on PUFA concentrations in women of childbearing age while stratifying by FADS genotype. The influence of fish consumption on lipid profile, and markers of inflammation and oxidative stress was also examined.

METHODS

Healthy women (n = 49) provided a buccal swab which was analysed for FADS2 genotype (rs3834458; T/deletion). Participants were stratified according to genotype and randomised to an intervention group to receive either no fish (n = 18), 1 portion (n = 14) or 2 portions (n = 17) (140 g per portion) of fish per week for a period of 8 weeks. Serum PUFA was analysed at baseline and post-intervention. Lipid profile, and markers of inflammation and oxidative stress were also analysed.

RESULTS

Participants consuming 2 portions of fish per week had significantly higher concentrations of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and total n-3 PUFA, and a lower n-6:n-3 ratio compared to those in the no fish or 1 portion per week group (all p < 0.05). Fish consumption did not have a significant effect on biomarkers of oxidative stress, inflammation and lipid profile in the current study.

CONCLUSION

Consumption of 2 portions of fish per week has beneficial effects on biological n-3 PUFA concentrations in women of childbearing age; however, no effects on oxidative stress, inflammation or lipid profile were observed. This trial was registered at www.clinicaltrials.gov (NCT03765580), registered December 2018.

Dietary n-3 but not n-6 fatty acids modulate anthropometry and fertility indices in high-fat diet fed rats: a two-generation study

The present study assessed the modulatory potentials of dietary n-3 [α-linolenic acid (ALA, 18:3n-3, eicosapentaenoic acid (EPA, 20:5n-3 + docosahexaenoic acid (DHA) 22:6n-3), and n-6 fatty acid (LA, 18:2n-6)] on anthropometric parameters and fertility indices in high-fat-fed rats. Weanling female Wistar rats were fed with control diet (7% lard), high-fat diet (35% lard, HFL), high-fat with fish oil (21% fish oil + 14% lard, HFF), high-fat with canola oil (21% canola oil + 14% lard, HFC) and high-fat with sunflower oil (21% sunflower oil + 14% lard, HFS) for 2 months, mated and continued on their diets during pregnancy. At gestation day 18-20, the intra-uterine environment was examined in representative rats, and the rest were allowed for delivering pups. The pups after lactation were subjected to mating and feeding trials as above. Growth parameters (body weight, body length (BL), abdominal circumference (AC), thoracic circumference (TC), and Lee index and fertility parameters (litter size and sex ratio) were studied. Feeding HFL diet increased BL (16%), AC (33%) and TC (21%) compared to control (p < 0.05). Adipose tissue accumulation was 11% higher in the HFL group compared to control and was lowered with n-3 fatty acid incorporation in the diet. HFL group exhibited a lower percentage of fertility, pregnancy, and delivery indices. Litter size was decreased by 20%, and litter weight was increased by 23% in HFL group compared to control with more male pups. Our study indicated that n-3 to a larger extent than n-6 fatty acids modulated high-fat induced changes in the anthropometric parameters and fertility indices.

Structured form of DHA prevents neurodegenerative disorders: A better insight into the pathophysiology and the mechanism of DHA transport to the brain

Docosahexaenoic acid (DHA) is one of the most important fatty acids that plays a critical role in maintaining proper brain function and cognitive development. Deficiency of DHA leads to several neurodegenerative disorders and, therefore, dietary supplementations of these fatty acids are essential to maintain cognitive health. However, the complete picture of how DHA is incorporated into the brain is yet to be explored. In general, the de novo synthesis of DHA is poor, and targeting the brain with specific phospholipid carriers provides novel insights into the process of reduction of disease progression. Recent studies have suggested that compared to triacylglycerol form of DHA, esterified form of DHA (i.e., lysophosphatidylcholine [lysoPC]) is better incorporated into the brain. Free DHA is transported across the outer membrane leaflet of the blood-brain barrier via APOE4 receptors, whereas DHA-lysoPC is transported across the inner membrane leaflet of the blood-brain barrier via a specific protein called Mfsd2a. Dietary supplementation of this lysoPC specific form of DHA is a novel therapy and is used to decrease the risk of various neurodegenerative disorders. Currently, structured glycerides of DHA - novel nutraceutical agents - are being widely used for the prevention and treatment of various neurological diseases. However, it is important to fully understand their metabolic regulation and mechanism of transportation to the brain. This article comprehensively reviews various studies that have evaluated the bioavailability of DHA, mechanisms of DHA transport, and role of DHA in preventing neurodegenerative disorders, which provides better insight into the pathophysiology of these disorders and use of structured DHA in improving neurological health.

Verbal Memory Performance in Depressed Children and Adolescents: Associations with EPA but Not DHA and Depression Severity

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) have been described as positively associated with cognitive functioning. Current meta-analyses have identified eicosapentaenoic acid (EPA) as potentially more effective than docosahexaenoic acid (DHA). An especially vulnerable subgroup that might benefit from these beneficial effects are depressed youths. In this study, we examined associations between red blood cell (RBC) DHA and EPA levels and depression severity and verbal memory performance in a sample of 107 moderately (n = 63) and severely (n = 44) depressed youths. The findings showed that youths with high RBC EPA levels had steeper learning curves compared to those with moderate or low RBC EPA levels (Pillai's Trace = 0.195, p = 0.027, η_p² = 0.097). No associations between RBC DHA levels or depression severity and verbal memory performance were observed. Our results further confirm previous findings indicating a more important role of EPA compared to DHA in relation to cognitive functioning. Future research should further investigate the differential role of EPA and DHA concerning cognitive functioning in depressed youths. Evidence supporting beneficial supplementation effects could potentially establish a recommendation for a natural and easily accessible intervention for cognitive improvement or remission.

Camelina sativa Oil and Camelina Cake as Sources of Polyunsaturated Fatty Acids in the Diets of Laying Hens: Effect on Hen Performance, Fatty Acid Profile of Yolk Lipids, and Egg Sensory Quality

The present study aimed to determine the effect of the use of Camelina sativa oil as a dietary ingredient for laying hens on their growth performance, fatty acid profile of yolk lipids, and egg quality parameters. In the experiment, 72 Hy-Line laying hens aged 26 weeks were randomly assigned to three groups with four treatments. Control group (I) was fed the diet containing 4% rapeseed oil (RO group). Experimental groups were fed diets containing 4% camelina oil (CSO group) and 10% camelina cake (group CSC). Feed consumption was measured for each group. The number of laid eggs and their weight were recorded every day. Eggs for the assessment of quality parameters were collected in the last 3 days of the experiment. Egg quality, chemical composition of yolk, and fatty acid profile were determined. Organoleptic evaluation was performed on boiled eggs. The inclusion of C. sativa oil or camelina cake in the laying hen diet did not affect egg weight, albumen quality, or taste and flavor. The experimental groups also showed a tendency toward an increase in the proportion of yolk in the egg (%). Addition of 4% camelina oil or 10% camelina cake to the diet of laying hens reduced monounsaturated fatty acid level in yolk lipids and significantly increased n-3 PUFA content, in particular ALA, EPA, and DHA, compared to the control group.

Enhanced physical and cognitive performance in active duty Airmen: evidence from a randomized multimodal physical fitness and nutritional intervention

Achieving military mission objectives requires high levels of performance from Airmen who operate under extreme physical and cognitive demands. Thus, there is a critical need to establish scientific interventions to enhance physical fitness and cognitive performance-promoting the resilience of Airmen and aiding in mission success. We therefore conducted a comprehensive, 12-week randomized controlled trial in active-duty Air Force Airmen (n = 148) to compare the efficacy of a multimodal intervention comprised of high-intensity interval aerobic fitness and strength training paired with a novel nutritional supplement [comprised of β-hydroxy β-methylbutyrate (HMB), lutein, phospholipids, DHA and selected micronutrients including B12 and folic acid] to high-intensity interval aerobic fitness and strength training paired with a standard of care placebo beverage. The exercise intervention alone improved several dimensions of physical fitness [strength and endurance (+ 8.3%), power (+ 0.85%), mobility and stability (+ 22%), heart rate (- 1.1%) and lean muscle mass (+ 1.4%)] and cognitive function [(episodic memory (+ 9.5%), processing efficiency (+ 7.5%), executive function reaction time (- 4.8%) and fluid intelligence accuracy (+ 19.5%)]. Relative to exercise training alone, the multimodal fitness and nutritional intervention further improved working memory (+ 9.0%), fluid intelligence reaction time (- 7.7%), processing efficiency (+ 1.8%), heart rate (- 2.4%) and lean muscle mass (+ 1.5%). These findings establish the efficacy of a multimodal intervention that incorporates aerobic fitness and strength training with a novel nutritional supplement to enhance military performance objectives and to provide optimal exercise training and nutritional support for the modern warfighter.

Regulation of Reactive Oxygen Species-Mediated Damage in the Pathogenesis of Schizophrenia

The biochemical integrity of the brain is paramount to the function of the central nervous system, and oxidative stress is a key contributor to cerebral biochemical impairment. Oxidative stress, which occurs when an imbalance arises between the production of reactive oxygen species (ROS) and the efficacy of the antioxidant defense mechanism, is believed to play a role in the pathophysiology of various brain disorders. One such disorder, schizophrenia, not only causes lifelong disability but also induces severe emotional distress; however, because of its onset in early adolescence or adulthood and its progressive development, consuming natural antioxidant products may help regulate the pathogenesis of schizophrenia. Therefore, elucidating the functions of ROS and dietary antioxidants in the pathogenesis of schizophrenia could help formulate improved therapeutic strategies for its prevention and treatment. This review focuses specifically on the roles of ROS and oxidative damage in the pathophysiology of schizophrenia, as well as the effects of nutrition, antipsychotic use, cognitive therapies, and quality of life on patients with schizophrenia. By improving our understanding of the effects of various nutrients on schizophrenia, it may become possible to develop nutritional strategies and supplements to treat the disorder, alleviate its symptoms, and facilitate long-term recovery.

Levels of n-3 and n-6 Fatty Acids in Maternal Erythrocytes during Pregnancy and in Human Milk and Its Association with Perinatal Mental Health

Omega-3 long-chain polyunsaturated fatty acid (n-3 FA) status may be associated with mood disorders. Here, we evaluated the potential association between antenatal depression/anxiety and n-3/n-6 FA in (a) maternal erythrocytes and (b) human milk. In addition, we explored associations between n-3/n-6 FA in erythrocytes and in human milk and postpartum depression, while controlling for antenatal depression. Twenty-seven pregnant women diagnosed with a current major depressive disorder (MDD; n = 9), anxiety disorder (AD; n = 10) or a mixed anxiety-depression disorder (MADD; n = 8), and 40 healthy controls were included. n-3/n-6 FA were determined in maternal erythrocytes in gestational week 32 and in human milk in postpartum week 1. In the first week postpartum, the Edinburgh-Postnatal-Depression-Questionnaire was used to assess postpartum depression. Results show that women with M(A)DD had significantly lower erythrocyte levels of total n-3 FA, EPA, DHA and DGLA, and significantly higher n-6 DPA, and n-6:n-3, AA:EPA and n-6 DPA:DHA ratios compared to healthy controls. No significant associations between antenatal depression or anxiety and n-3/n-6 FA in human milk were found. After controlling for antenatal mental health, n-3/n-6 FA in maternal erythrocytes or in human milk were not significantly associated with postpartum depression. In conclusion, antenatal depression, alone or with an anxiety disorder, was associated with lower n-3 FA levels and higher n-6:n-3 FA ratios in maternal erythrocytes during gestation. This study provides some insights into the associations between n-3/n-6 FA levels during pregnancy and lactation and perinatal mental health.

ω-3 and ω-6 Polyunsaturated Fatty Acids, Obesity and Cancer

Recently, nutraceutical bioactive compounds in foods have been discovered for their potential health benefits regarding the prevention of chronic disorders, such as cancer, and inflammatory, cardiovascular, and metabolic diseases. Dietary omega-3 polyunsaturated fatty acids (ω-3PUFAs), including alpha-linolenic acid, docosapentaenoic acid, and eicosapentaenoic acid, are mostly attractive. They are available for the customers worldwide from commonly used foods and/or as components of commercial food supplements. The anti-inflammatory and hypotriglyceridemic effects of these fatty acids are well known, whereas pro-inflammatory properties have been recognized in their dietary counterparts, the ω-6PUFAs. Both ω-3 and ω-6PUFAs contribute to the production of lipid mediators such as endocannabinoids that are notably involved in control of food intake, energy sensing, and food-related disorders. In this review, we present ω-3 and ω-6PUFAs and their derivatives, endocannabinoids; discuss the anti-obesity effects of ω-3PUFAs; their roles in inflammation and colorectal cancer development; and how their action can be co-preventative and co-therapeutic.

Efficient direct shoot organogenesis and genetic stability in micropropagated sacha inchi (Plukenetia volubilis L.)

OBJECTIVE

It is necessary to improve biotech platforms based on in vitro cell tissue culture to support sacha inchi (Plukenetia volubilis L.) research programs and draw on the nutritional value of the high polyunsaturated fatty acid content of its oilseed. Here, we developed a rapid and efficient method for induction and direct in vitro shoot development for this species.

RESULTS

Shoots were generated from hypocotyl explants. The highest organogenic response was obtained in woody plant medium supplemented with 1 mg/L thidiazuron and 0.5 mg/L zeatin supplemented with L-glutamine, adenine hemisulfate, and L-arginine. Shoots obtained using this medium were transferred and subcultivated with different concentrations of indole-3-butyric acid and 1-naphthylacetic acid for rooting. For the first time, a histological analysis was performed supporting direct organogenic development in this species. The plantlets obtained were transferred ex vitro with a survival percentage of 80%. The genetic stability of the plants recovered was confirmed by randomly amplified polymorphic DNA analysis. All results indicate that it would be possible to stimulate direct shoot formation from hypocotyls to support the sustainable use of this species.

Genetic variants in FADS1 and ELOVL2 increase level of arachidonic acid and the risk of Alzheimer's disease in the Tunisian population

Polyunsaturated fatty acids (PUFAs) are closely related to various physiological conditions. In several age-related diseases including Alzheimer's disease (AD) altered PUFAs metabolism has been reported. However, the mechanism behind PUFAs impairment and AD developpement remains unclear. In humans, PUFAs biosynthesis requires delta-5 desaturase (D5D), delta-6 desaturase (D6D) and elongase 2 activities; which are encoded by fatty acid desaturase 1 (FADS1), fatty acid desaturase 2 (FADS2), and elongation of very-long-chain fatty acids-like 2 (ELOVL2) genes, respectively. In the present work, we aim to assess whether genetic variants in FADS1, FADS2 and ELOVL2 genes influence plasma and erythrocyte PUFA composition and AD risk. A case-control study was carried out in 113 AD patients and 161 healthy controls.Rs174556, rs174617, and rs3756963 of FADS1, FADS2, and ELOVL2 genes, respectively were genotyped using PCR-RFLP. PUFA levels were quantified using Gas Chromatography. Genotype distributions of rs174556 (FADS1) and rs3756963 (ELOVL2) were different between case and control groups. The genotype TT of rs174556 and rs3756963 single nucleotide polymorphism (SNP) increases significantly the risk of AD in our population. PUFA analysis showed higher plasma and erythrocyte arachidonic acid (AA) level in patients with AD, whereas only plasma docosahexaenoic acid (DHA) was significantly decreased in AD patients. The indexes AA/Dihomo-gamma-linolenic acid (DGLA) and C24:4n-6/Adrenic acid (AdA) were both higher in the AD group. Interestingly, patients with TT genotype of rs174556 presented higher AA level and AA/DGLA index in both plasma and erythrocyte. In addition, higher AA and AA/DGLA index were observed in erythrocyte of TT genotype ofrs3756963 carrier's patients. Along with, positive correlation between AA/DGLA index, age or Gamma-linolenic acid (GLA)/ Linoleic acid (LA) index was seen in erythrocyte and /or plasma of AD patients. After adjustment for confounding factors, the genotype TT of rs174556, erythrocyte AA and AA/DGLA index were found to be predictive risk factors for AD while plasma DHA was found associated with lower AD risk. Both rs174556 and rs3756963 influence AD risk in the Tunisian population and they are likely associated with high AA level. The combination of the two variants increases further the susceptibility to AD. We suggest that FADS1 and ELOVL2 variants could likely regulate the efficiency of AA biosynthesis which could be at the origin of inflammatory derivate.

Effect of the Leavening Agent on the Compositional and Sensorial Characteristics of Bread Fortified with Flaxseed Cake

Health and well-being improvement is currently driving innovation in bread, using a wide variety of value-added compounds as extra ingredients, including food industry by-products in a circular economy concept. In this context, this research aimed at evaluating the effect of the fortification of bread with different percentages of flaxseed cake, comparing two leavening agents: sourdough and baker’s yeast. Sensorial, physicochemical, and nutritional properties, including pH, the main fermentative metabolites, fatty acids, total phenols, antioxidant capacity, and volatile organic compounds were determined for fortified bread. The results showed a significant improvement of nutraceutical profile of the bread fortified with flaxseed cake in a dose-dependent manner. Regardless of the leavening agent, the fortification determined a decrease of n-6:n-3 ratio, reaching the recommended value (<3) already at the 7.5% level. Furthermore, under the same fortification level, sourdough breads showed a higher level of total phenols and antiradical activity than baker’s yeast breads. Sensory profiles were instead deeply influenced by both the fortification percentage and the leavening agents. In conclusion, considering both nutritional and sensory results, the best formulation as a function of leavening agent utilized was defined as 5% and 7.5% when sourdough and baker’s yeast were used, respectively.

The Impact of Antioxidant Supplementation and Heat Stress on Carcass Characteristics, Muscle Nutritional Profile and Functionality of Lamb Meat

The impact of antioxidant supplementation and short-term heat stress on lamb body weight gain, meat nutritional profile and functionality (storage stability of lipids and colour) of lamb meat was investigated. A total of 48 crossbred ((Merino × Border Leicester) × Dorset) lambs (42 ± 2 kg body weight, 7 mo age) were randomly allocated to three dietary treatments (n = 16) by liveweight (LW) that differed in dosage of vitamin E and selenium (Se) in the diet. Vitamin E and Se levels in the control (CON), moderate (MOD) and supranutritional (SUP) dietary treatments were 28, 130 and 228 mg/kg DM as α-tocopherol acetate and 0.16, 0.66 and 1.16 mg Se as SelPlex™/kg DM, respectively. After four weeks of feeding in individual pens, including one week of adaptation, lambs were exposed to two heat treatments. Animals were moved to metabolism cages for one week and subjected to heat treatments: thermoneutral (TN; 18-21 °C and 40-50% relative humidity) and heat stress (HS; 28-40 °C and 30-40% relative humidity) conditions, respectively. Final LW and hot carcass weight were influenced by dietary treatments with higher final live weight (FLW) (p = 0.05; 46.8 vs. 44.4 and 43.8 kg, respectively) and hot carcass weight (HCW) (p = 0.01; 22.5 vs. 21.3 and 21.0 kg, respectively) recorded in lambs fed the SUP as opposed to the CON and MOD diets. Vitamin E concentration in the longissimus lumborum (LL) muscle tended to be higher in lambs fed MOD or SUP diets than the CON group. Lipid oxidation of aged meat at 72 h of simulated retail display was reduced by antioxidant supplementation. Short-term (one week) heat stress treatment significantly increased muscle linoleic acid and total omega-6 concentrations compared with the CON group. The results demonstrate that four-week antioxidant supplementation at the SUP level improved animal productivity by increasing LW and carcass weight and the functionality of meat exhibited by reduced lipid oxidation. An increase in muscle omega-6 fatty acid concentration from short-term heat stress may induce oxidative stress via proinflammatory action.

Beneficial effects of omega-3 fatty acid supplementation in schizophrenia: possible mechanisms

BACKGROUND

Schizophrenia is a serious long-term psychotic disorder marked by positive and negative symptoms, severe behavioral problems and cognitive function deficits. The cause of this disorder is not completely clear, but is suggested to be multifactorial, involving both inherited and environmental factors. Since human brain regulates all behaviour, studies have focused on identifying changes in neurobiology and biochemistry of brain in schizophrenia. Brain is the most lipid rich organ (approximately 50% of brain dry weight). Total brain lipids is constituted of more than 60% of phospholipids, in which docosahexaenoic acid (DHA, 22:6n-3) is the most abundant (more than 40%) polyunsaturated fatty acid (PUFA) in brain membrane phospholipids. Results from numerous studies have shown significant decreases of PUFAs, in particular, DHA in peripheral blood (plasma and erythrocyte membranes) as well as brain of schizophrenia patients at different developmental phases of the disorder. PUFA deficiency has been associated to psychotic symptoms and cognitive deficits in schizophrenia. These findings have led to a number of clinical trials examining whether dietary omega-3 fatty acid supplementation could improve the course of illness in patients with schizophrenia. Results are inconsistent. Some report beneficial whereas others show not effective. The discrepancy can be attributed to the heterogeneity of patient population.

METHODS

In this review, results from recent experimental and clinical studies, which focus on illustrating the role of PUFAs in the development of schizophrenia were examined. The rationale why omega-3 supplementation was beneficial on symptoms (presented by subscales of the positive and negative symptom scale (PANSS), and cognitive functions in certain patients but not others was reviewed. The potential mechanisms underlying the beneficial effects were discussed.

RESULTS

Omega-3 fatty acid supplementation reduced the conversion rate to psychosis and improved both positive and negative symptoms and global functions in adolescents at ultra-high risk for psychosis. Omega-3 fatty acid supplementation could also improve negative symptoms and global functions in the first-episode patients with schizophrenia, but improve mainly total or general PANSS subscales in chronic patients. Patients with low PUFA (particularly DHA) baseline in blood were more responsive to the omega-3 fatty acid intervention.

CONCLUSION

Omega-3 supplementation is more effective in reducing psychotic symptom severity in young adults or adolescents in the prodromal phase of schizophrenia who have low omega-3 baseline. Omega-3 supplementation was more effective in patients with low PUFA baseline. It suggests that patients with predefined lipid levels might benefit from lipid treatments, but more controlled clinical trials are warranted.

Nutrition interventions in populations with mental health conditions: a scoping review

Nutrition is a modifiable factor for intervention in mental disorders. This scoping review characterized nutrition intervention research in mental disorders. A 3-category framework characterized nutrition interventions: Guide (e.g., counselling), Provide (e.g., food provisions), and Add (e.g., supplementation). Nutrition interventions were classified as single-component (e.g., Guide) or complex (e.g., Guide-Provide). Sixty-nine trials met inclusion criteria, 96% were randomized controlled trials. Most commonly diagnosed mental disorders were depressive disorder (i.e., persistent) or major depressive disorder (n = 39), schizophrenia (n = 17), and other psychotic disorders (n = 13). Few trials included patients with anxiety disorders (n = 2) or bipolar disorders (n = 3). Several trials (n = 15, 22%) assessed and implemented nutrition interventions to improve dietary patterns, of which 11 (73%) reported statistically significant and clinically important positive effects of nutrition interventions on mental disorders. The majority of the trials (n = 61, 90%) investigated supplementation, most commonly adding essential fatty acids, vitamins, or minerals. The majority (n = 48, 70%) reported either statistically significant or clinically important effect and 31 (51%) reported both. Though most interventions led to statistically significant improvements, trials were heterogeneous for targeted mental disorders, nutrition interventions, and outcomes assessed. Given considerable heterogeneity, further research from robust and clinically relevant trials is required to support high-quality health care with effective nutrition interventions. Novelty Future research on whole-diet interventions powered to detect changes in mental health outcomes as primary objectives is needed. Dietitians may be an opportunity to improve feasibility and efficacy of nutrition interventions for mental disorder patients. Dietitians may be of value to educate mental health practitioners on the importance of nutrition.

Physicochemical Properties and Liposomal Formulations of Hydrolysate Fractions of Four Sea Cucumbers (Holothuroidea: Echinodermata) from the Northwestern Algerian Coast

To promote the nutritional and pharmacological values of four sea cucumber species (Holothuria poli, H. tubulosa, H. arguinensis, and H. sanctori), harvested from the Algerian coast, we aimed to study their proximate composition, fatty acid profile and angiotensin-converting enzyme (ACE) inhibitory activity. Their phospholipids were also used to elaborate nanoliposomes and to encapsulate peptides obtained from the same source. After the physico-chemical characterization of nanoliposomes and peptides, in vitro analyses were realized. The four holothurian species showed a high amount of protein (49.26-69.34%), and an impressive lipid profile of 27 fatty acids, mainly composed of polar fatty acids (91.16-93.85%), with a high polyunsaturated fatty acids (PUFA) content (50.90-71.80%), particularly eicosapentaenoic acid (EPA) (5.07-8.76%) and docosahexaenoic acid (DHA) (4.86-7.25%). A high phospholipids amount was also found (55.20-69.85%), mainly composed of phosphatidylcholine (PC) (51.48-58.56%). Their peptide fractions exhibited a high ACE inhibitory activity (IC50 0.30 to 0.51 mg/mL). The results also showed that the nanoliposomes do not induce cytotoxicity and cell death in human MSCs and no perturbation of proliferation for all the times and the tested concentrations, as well as the combined nanoliposomes and hydrolysates (HTS) at a concentration of 0.1 mg/mL. All four sea cucumbers show potential as a new source for omega-3, omega-6, and bioactive peptides.

Dietary n-6/n-3 Ratio Influences Brain Fatty Acid Composition in Adult Rats

There is mounting evidence that diets supplemented with polyunsaturated fatty acids (PUFA) can impact brain biology and functions. This study investigated whether moderately high-fat diets differing in n-6/n-3 fatty acid ratio could impact fatty acid composition in regions of the brain linked to various psychopathologies. Adult male Sprague Dawley rats consumed isocaloric diets (35% kcal from fat) containing different ratios of linoleic acid (n-6) and alpha-linolenic acid (n-3) for 2 months. It was found that the profiles of PUFA in the prefrontal cortex, hippocampus, and hypothalamus reflected the fatty acid composition of the diet. In addition, region-specific changes in saturated fatty acids and monounsaturated fatty acids were detected in the hypothalamus, but not in the hippocampus or prefrontal cortex. This study in adult rats demonstrates that fatty acid remodeling in the brain by diet can occur within months and provides additional evidence for the suggestion that diet could impact mental health.

Targeted Biomedical Treatment for Autism Spectrum Disorders

BACKGROUND

A diagnosis of autism spectrum disorders (ASD) represents presentations with impairment in communication and behaviour that vary considerably in their clinical manifestations and etiology as well as in their likely pathophysiology. A growing body of data indicates that the deleterious effect of oxidative stress, mitochondrial dysfunction, immune dysregulation and neuroinflammation, as well as their interconnections are important aspects of the pathophysiology of ASD. Glutathione deficiency decreases the mitochondrial protection against oxidants and tumor necrosis factor (TNF)-α; immune dysregulation and inflammation inhibit mitochondrial function through TNF-α; autoantibodies against the folate receptors underpin cerebral folate deficiency, resulting in disturbed methylation, and mitochondrial dysfunction. Such pathophysiological processes can arise from environmental and epigenetic factors as well as their combined interactions, such as environmental toxicant exposures in individuals with (epi)genetically impaired detoxification. The emerging evidence on biochemical alterations in ASD is forming the basis for treatments aimed to target its biological underpinnings, which is of some importance, given the uncertain and slow effects of the various educational interventions most commonly used.

METHODS

Literature-based review of the biomedical treatment options for ASD that are derived from established pathophysiological processes.

RESULTS

Most proposed biomedical treatments show significant clinical utility only in ASD subgroups, with specified pre-treatment biomarkers that are ameliorated by the specified treatment. For example, folinic acid supplementation has positive effects in ASD patients with identified folate receptor autoantibodies, whilst the clinical utility of methylcobalamine is apparent in ASD patients with impaired methylation capacity. Mitochondrial modulating cofactors should be considered when mitochondrial dysfunction is evident, although further research is required to identify the most appropriate single or combined treatment. Multivitamins/multiminerals formulas, as well as biotin, seem appropriate following the identification of metabolic abnormalities, with doses tapered to individual requirements. A promising area, requiring further investigations, is the utilization of antipurinergic therapies, such as low dose suramin.

CONCLUSION

The assessment and identification of relevant physiological alterations and targeted intervention are more likely to produce positive treatment outcomes. As such, current evidence indicates the utility of an approach based on personalized and evidence-based medicine, rather than treatment targeted to all that may not always be beneficial (primum non nocere).

Strengthening the Immune System and Reducing Inflammation and Oxidative Stress through Diet and Nutrition: Considerations during the COVID-19 Crisis

The coronavirus-disease 2019 (COVID-19) was announced as a global pandemic by the World Health Organization. Challenges arise concerning how to optimally support the immune system in the general population, especially under self-confinement. An optimal immune response depends on an adequate diet and nutrition in order to keep infection at bay. For example, sufficient protein intake is crucial for optimal antibody production. Low micronutrient status, such as of vitamin A or zinc, has been associated with increased infection risk. Frequently, poor nutrient status is associated with inflammation and oxidative stress, which in turn can impact the immune system. Dietary constituents with especially high anti-inflammatory and antioxidant capacity include vitamin C, vitamin E, and phytochemicals such as carotenoids and polyphenols. Several of these can interact with transcription factors such as NF-kB and Nrf-2, related to anti-inflammatory and antioxidant effects, respectively. Vitamin D in particular may perturb viral cellular infection via interacting with cell entry receptors (angiotensin converting enzyme 2), ACE2. Dietary fiber, fermented by the gut microbiota into short-chain fatty acids, has also been shown to produce anti-inflammatory effects. In this review, we highlight the importance of an optimal status of relevant nutrients to effectively reduce inflammation and oxidative stress, thereby strengthening the immune system during the COVID-19 crisis.

Isolation and functional analyses of PvFAD2 and PvFAD3 involved in the biosynthesis of polyunsaturated fatty acids from Sacha Inchi (Plukenetia volubilis)

The development of ω-3 fatty acid-rich vegetable oils is essential to enrich the production of functional foods. Sacha Inchi (Plukenetia volubilis L.) is a unique oilseed crop with much potential. Its seeds contain rich polyunsaturated fatty acids (PUFAs), especially linoleic acid (LA, C18:2) and α-linolenic acid (ALA, C18:3). Endoplasmic reticulum -located ω-6 and ω-3 fatty acid desaturases (FAD) are responsible for the biosynthesis of LA and ALA, respectively, in plant seeds. Here, we isolated two full-length FAD genes from Sacha Inchi, named PvFAD2 and PvFAD3, which encoded predicted amino acid residues of 384 and 379 in protein, respectively. Protein sequence and subcellular localization analysis revealed that they were located in the endoplasmic reticulum (ER). Heterologous expression in Saccharomyces cerevisiae confirmed that PvFAD2 and PvFAD3 could catalyze LA and ALA synthesis, respectively. The stability and catalytic efficiency of the PvFAD3 protein may be closely related to temperature. In transgenic tobacco, using seed-specific expression promoters, PvFAD2 and PvFAD3 significantly promotes the production of LA (from 68% to 70.5%) and ALA (from 0.7% to 3.1%) in seed oil. These results show that PvFAD2 and PvFAD3 do, indeed, function as crucial enzymes for PUFAs biosynthesis, and provide a key gene source for the sustainable production of lipids with tailored fatty acid compositions via genetic engineering in other oil crops.

Genetics of Omega-3 Long-Chain Polyunsaturated Fatty Acid Metabolism and Meat Eating Quality in Tattykeel Australian White Lambs

Meat eating quality with a healthy composition hinges on intramuscular fat (IMF), fat melting point (FMP), tenderness, juiciness, flavour and omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) content. These health-beneficial n-3 LC-PUFA play significant roles in optimal cardiovascular, retinal, maternal and childhood brain functions, and include alpha linolenic (ALA), eicosapentaenoic (EPA), docosahexaenoic (DHA) and docosapentaenoic (DPA) acids. The primary objective of this review was to access, retrieve, synthesise and critically appraise the published literature on the synthesis, metabolism and genetics of n-3 LC-PUFA and meat eating quality. Studies on IMF content, FMP and fatty acid composition were reviewed to identify knowledge gaps that can inform future research with Tattykeel Australian White (TAW) lambs. The TAW is a new sheep breed exclusive to MARGRA brand of lamb with an outstanding low fat melting point (28-39°C), high n-3 LC-PUFA EPA+DHA content (33-69mg/100g), marbling (3.4-8.2%), tenderness (20.0-38.5N) and overall consumer liking (7.9-8.5). However, correlations between n-3 LC-PUFA profile, stearoyl-CoA desaturase (SCD), fatty acid binding protein 4 (FABP4), fatty acid synthase (FASN), other lipogenic genes and meat quality traits present major knowledge gaps. The review also identified research opportunities in nutrition-genetics interactions aimed at a greater understanding of the genetics of n-3 LC-PUFA, feedlot finishing performance, carcass traits and eating quality in the TAW sheep. It was concluded that studies on IMF, FMP and n-3 LC-PUFA profiles in parental and progeny generations of TAW sheep will be foundational for the genetic selection of healthy lamb eating qualities and provide useful insights into their correlations with SCD, FASN and FABP4 genes.

Evaluation of SMOFlipid in Pediatric Intestinal-Failure Patients and Its Effects on Essential Fatty Acid Levels

BACKGROUND

SMOFlipid is a mixed-lipid emulsion approved for adults in the United States as an alternative to soybean oil-based lipid (SO). There are limited data on the use of SMOFlipid in pediatrics and its effect on the fatty acid (FA) profile. Our objective was to characterize changes in FA profile, liver function, and growth in pediatric patients with intestinal failure (IF), following transition from SO or a fish-oil (FO) and SO combination to SMOFlipid.

METHODS

A retrospective case series was conducted on pediatric parenteral nutrition-dependent IF patients transitioned to SMOFlipid. Demographics, anthropometrics, labs, and achievement of nutrition goals were assessed. Linear mixed-effect models assessed effects on FA levels and clinical outcomes.

RESULTS

One hundred thirty-nine FA panels were collected from 20 patients. Median SMOFlipid dose at study completion was 2 g/kg/d (interquartile range, 1.6-2). During the 1.5 years after SMOFlipid initiation, ω-6 FA increased to physiologic levels, arachidonic acid increased from 298 to 461 nmol/mL (P < .001), and linoleic acid increased from 1172 to 1922 nmol/mL (P < .001). ω-3 FA remained within normal limits. Body mass index z-score and length z-score increased, though no significant changes were found. In addition, no significant changes were found in mead acid, hepatic function, triene-to-tetraene ratio, or triglycerides.

CONCLUSION

In 20 pediatric IF patients, SMOFlipid allowed greater ω-6 FA provision while maintaining ω-3 FA, hepatic function, and patient growth. This longitudinal study identified improved FA profile associated with SMOFlipid use in comparison with SO with or without FO.

Human health benefits of very-long-chain polyunsaturated fatty acids from microalgae

Microalgae are single-cell, photosynthetic organisms whose biodiversity places them at the forefront of biological producers of high-value molecules including lipids and pigments. Some of these organisms particular are capable of synthesizing n-3 very long chain polyunsaturated fatty acids (VLC-PUFAs), known to have beneficial effects on human health. Indeed, VLC-PUFAs are the precursors of many signaling molecules in humans involved in the complexities of inflammatory processes. This mini-review provides an inventory of knowledge on the synthesis of VLC-PUFAs in microalgae and on the diversity of signaling molecules (prostanoids, leukotrienes, SPMs, EFOX, isoprostanoids) that arise in humans from VLC-PUFAs.

Cross-sectional association of seafood consumption, polyunsaturated fatty acids and depressive symptoms in two Torres Strait communities

Background Dietary intake of long-chain omega 3 (n-3) polyunsaturated fatty acids (LCPUFA) represents a putative modifiable risk factor for depression, and a high ratio of omega 6 (n-6) to n-3 LCPUFA is frequently observed in patients with major depressive disorder. Recent reports suggest that the availability of fish and seafood may be associated with lower depression rates. The aim of this study was to investigate associations of fish consumption and LCPUFA levels with depressive symptoms.Methods Participants for this cross-sectional study (n=206) were recruited at a community screening programme in two Torres Strait Islander communities (Mer and Waiben). Depressive symptoms were assessed with the adapted Patient Health Questionnaire-9 (aPHQ-9) and diet with a structured questionnaire. LCPUFA concentrations were measured with a capillary dried blood spot system (PUFAcoat). Logistic and quantile regression modelling was used to test the relationship between seafood consumption, membrane LCPUFAs and depression scores.Results A higher blood n-6/3 LCPUFA ratio was associated with moderate/severe depression scores across both study sites (OR=1.59 (95%CI 1.09-2.34), P = .017). Seafood consumption was higher and the proportion of participants with aPHQ-9 scores above the cut-off for depression was lower on Mer (n = 100) compared with Waiben (n = 106). Higher seafood consumption was associated with lower depression scores on Waiben (B = -0.57 (95%CI -0.98 - -0.16), P = .006) but not on Mer.Conclusions Our findings support an association of n-3 LCPUFA from natural sources with depressive symptoms. The availability of fresh seafood in the local diet may represent a protective factor for depression in this setting.

Lipid and Lipoprotein Metabolism in Microglia

Microglia, once viewed as static bystanders with limited homeostatic functions, are now considered key players in the development of neuroinflammatory and neurodegenerative diseases. Microglial activation is a salient feature of neuroinflammation involving a dynamic process that generates multitudinous microglial phenotypes that can respond to a variety of situational cues in the central nervous system. Recently, a flurry of single cell RNA-sequencing studies have defined microglial phenotypes in unprecedented detail, and have highlighted robust changes in the expression of genes involved in lipid and lipoprotein metabolism. Increased expression of genes such as Apolipoprotein E (ApoE), Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) and Lipoprotein Lipase (LPL) in microglia during development, damage, and disease, suggest that increased lipid metabolism is needed to fuel protective cellular functions such as phagocytosis. This review describes our current understanding of lipid and lipoprotein metabolism in microglia, and highlights microglial lipid metabolism as a modifiable target for the treatment of neurodegenerative diseases such as Alzheimer's disease and multiple sclerosis.

Substrate structure and computation guided engineering of a lipase for omega-3 fatty acid selectivity

Enrichment of omega-3 fatty acids (ɷ-3 FAs) in natural oils is important to realize their health benefits. Lipases are promising catalysts to perform this enrichment, however, fatty acid specificity of lipases is poor. We attempted to improve the fatty acid selectivity of a lipase from Geobacillus thermoleovorans (GTL) by two approaches. In a semi-rational approach, amino acid positions critical for binding were identified by docking the substrate to the GTL and best substitutes at these positions were identified by site saturation mutagenesis followed by screening to obtain a variant of GTL (CM-GTL). In the second approach based on rational design, a variant of GTL was designed (DM-GTL) wherein the active site was narrowed by incorporating two heavier amino acids in the lining of acyl-binding pocket to hinder access to bulky ɷ-3 FAs. The affinities DM-GTL with designed substrates were evaluated in silico. Both, CM-GTL and DM-GTL have shown excellent ability to discriminate against the ɷ-3 FAs during hydrolysis of oils. Engineering the binding pocket of an enzyme of a complex substrate, such as a triglyceride, by incorporating the information on substrate structure and computationally derived binding modes, has resulted in designing two efficient lipase variants with improved substrate selectivity.

Resolvin D1 Prevents the Impairment in the Retention Memory and Hippocampal Damage in Rats Fed a Corn Oil-Based High Fat Diet by Upregulation of Nrf2 and Downregulation and Inactivation of p66Shc

This study investigated the effect of a high-fat diet rich in corn oil (CO-HFD) on the memory retention and hippocampal oxidative stress, inflammation, and apoptosis in rats, and examined if the underlying mechanisms involve modulating Resolvin D1 (RvD1) levels and activation of p⁶⁶Shc. Also, we tested if co-administration of RvD1 could prevent these neural adverse effects induced by CO-HFD. Adult male Wistar rats were divided into 4 groups (n = 18/each) as control fed standard diet (STD) (3.82 kcal/g), STD + RvD1 (0.2 µg/Kg, i.p/twice/week), CO-HFD (5.4 kcal/g), and CO-HFD + RvD1. All treatments were conducted for 8 weeks. With normal fasting glucose levels, CO-HFD induced hyperlipidemia, hyperinsulinemia, increased HOMA-IRI and reduced the rats' memory retention. In parallel, CO-HFD increased levels of reactive oxygen species (ROS), malondialdehyde (MDA), cytoplasmic cytochrome-c, and cleaved caspase-3 and significantly decreased levels of glutathione (GSH), Bcl-2, and manganese superoxide dismutase (MnSOD) in rats' hippocampi. Besides, CO-HFD significantly reduced hippocampal levels of docosahexaenoic acid (DHA) and RvD1, as well as total protein levels of Nrf2 and significantly increased nuclear protein levels of p-NF-κB. Concomitantly, CO-HFD increased hippocampal protein levels of p-JNK, p53, p⁶⁶Shc, p-p⁶⁶Shc, and NADPH oxidase. However, without altering plasma and serum levels of glucose, insulin, and lipids, co-administration of RvD1 to CO-HFD completely reversed all these events. It also resulted in similar effects in the STD fed-rats. In conclusion, CO-HFD impairs memory function and induces hippocampal damage by reducing levels of RvD1 and activation of JNK/p53/p⁶⁶Shc/NADPH oxidase, effects that are prevented by co-administration of RvD1.

Fatty acids and recurrence of major depressive disorder: combined analysis of two Dutch clinical cohorts

OBJECTIVE

Omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acid (PUFA) alterations in patients with major depressive disorder (MDD) have been shown to persist after remission. Whether these alterations are risk factors for MDD recurrence remains unknown. Here, we examined whether fatty acids predict time until MDD recurrence in remitted MDD patients.

METHODS

Data were used from remitted MDD patients of the Netherlands Study of Depression and Anxiety (n = 356) and the Depression Evaluation Longitudinal Therapy Assessment studies (n = 118). Associations of FAs with time until MDD recurrence up to 8-year follow-up were analyzed using Cox regression analyses. Study-specific estimates were pooled using mega- and meta-analysis techniques.

RESULTS

27.5% (NESDA) and 56.8% (DELTA) participants had an MDD recurrence. Pooled results showed that no FA was significantly associated with time until MDD recurrence (n-3 PUFAs: hazard ratio (HR) = 1.17, 95% confidence interval (CI) = 0.98-1.41, P = 0.082; n-6 PUFAs: HR = 1.08, 95% CI = 0.84-1.38, P = 0.55).

CONCLUSION

In remitted MDD patients, circulating PUFAs were not associated with prospective risk of MDD recurrence. Consequently, circulating PUFAs are unlikely to reflect a vulnerability marker for recurrence, so correcting n-3 PUFA 'deficits' through supplementation does not seem a promising option to prevent MDD recurrence.

Chlorella vulgaris cultivation in airlift photobioreactor with transparent draft tube: effect of hydrodynamics, light and carbon dioxide on biochemical profile particularly ω-6/ω-3 fatty acid ratio

Chlorella vulgaris is used for food and feed applications due to its nutraceutical, antioxidant and anticancer properties. An airlift photobioreactor comprising transparent draft tube was used for C. vulgaris cultivation. The effect of reactor parameters like hydrodynamics (0.3-1.5 vvm), light intensity (85-400 μmol m^-2 s^-1), photoperiod (12-24 h) and gas-phase carbon dioxide (CO₂) concentration (5-15% v/v) were evaluated on microalgae and associated bacterial growth, biochemical profile; with special emphasis on ω-3, ω-6 fatty acids, and vitamin B₁₂. The optimal growth of C. vulgaris without CO₂ supplementation was observed at 1.2 vvm, which was associated with higher algal productivity, chlorophyll, vitamin B₁₂ content, and bacterial load along with 72% of nitrate removal. The higher light intensity (400 μmol m^-2 s^-1) and photoperiod (24:0) increased biomass productivity and ω-3 fatty acid content (in lipid) up to 2-3 fold. The elevated levels of gas-phase CO₂ concentration (15% v/v) enhanced EPA content up to 7% and biomass productivity up to 171 mg L^-1 day^-1. However, the increase in CO₂ concentration lowered vitamin B₁₂ content (up to 30%) and bacterial load (2-3 log). Also, all the cultivation conditions favoured desirable ω-6/ω-3 ratio(in the range of 1-2).

Flaxseed Cake as a Tool for the Improvement of Nutraceutical and Sensorial Features of Sourdough Bread

Flaxseed has been recently studied for the formulation of healthy functional foods that are also useful for the prevention of chronic diseases. In this context, the production of sourdough bread fortified with different percentages of flaxseed cake was performed and the interactions among the bioactive compounds derived from both sourdough and flaxseed cake were investigated. The organoleptic properties as well as nutraceutical and chemical characteristics regarding pH, ethanol, lactic and acetic acid content, fatty acids profile, the concentration of total polyphenols, antioxidant capacity, and aroma volatile organic compounds were determined to evaluate the efficacy of leavening in the different matrices in comparison with the traditional bread. The results obtained demonstrated that flaxseed cake-enriched sourdough bread can represent a potential vehicle for bioactive compounds with the possibility of obtaining high-quality products with improved nutritional profiles and desired health attributes. Furthermore, the bread obtained with the addition of 7.5% of flaxseed cake was individuated as the best formulation to produce sourdough bread fortified with flaxseed cake by the overlap between three series of information coming from physical-chemical, nutritional, and sensorial analyses. In conclusion, in the operating conditions adopted, the use of flaxseed cake could represent a viable alternative for the production of fortified bread based on sourdough technology.

Associations of n-3, n-6 Fatty Acids Intakes and n-6:n-3 Ratio with the Risk of Depressive Symptoms: NHANES 2009-2016

Many studies have explored the association between n-3 fatty acids and depression, but research on the associations of n-6 fatty acids and n-6:n-3 ratio with depression is more scarce, and the results are controversial. Therefore, we conducted this cross-sectional study to explore the associations of n-3 and n-6 fatty acid intakes and n-6:n-3 ratio with the risk of depressive symptoms using data from National Health and Nutrition Examination Survey (NHANES) 2009–2016. Dietary data on n-3 and n-6 fatty acids were obtained through two 24-h dietary recall interviews, and were adjusted by energy. Depressive symptoms were measured by PHQ-9 (nine-item Patient Health Questionnaire). We applied logistic regression and restricted cubic spline models to assess the relationships of n-3 and n-6 fatty acids intake and n-6:n-3 ratio with the risk of depressive symptoms. A total of 17,431 individuals over 18 years old were enrolled in this study. In the multivariate-adjusted model 2, compared with the lowest category, the highest odd ratios (ORs) with 95% confidence intervals (CIs) for n-3 fatty acid intake and n-6:n-3 ratio were 0.71 (0.55–0.92) and 1.66 (1.10–2.50), and middle OR (95% CI) for n-6 fatty acid intake was 0.72 (0.56–0.92), respectively. Our study suggests that n-3 and n-6 fatty acids intake were inversely associated with the risk of depressive symptoms, while the n-6:n-3 ratio was positively associated with the risk of depressive symptoms.

Dietary Fatty Acids and Microbiota-Brain Communication in Neuropsychiatric Diseases

The gut-brain axis is a multimodal communication system along which immune, metabolic, autonomic, endocrine and enteric nervous signals can shape host physiology and determine liability, development and progression of a vast number of human diseases. Here, we broadly discussed the current knowledge about the either beneficial or deleterious impact of dietary fatty acids on microbiota-brain communication (MBC), and the multiple mechanisms by which different types of lipids can modify gut microbial ecosystem and contribute to the pathophysiology of major neuropsychiatric diseases (NPDs), such as schizophrenia (SCZ), depression and autism spectrum disorders (ASD).

Fatty Acids and Effects on In Vitro and In Vivo Models of Liver Steatosis

BACKGROUND

Fatty liver, or steatosis, is a condition of excess accumulation of lipids, mainly under form of triglycerides (TG), in the liver, and it is the hallmark of non-alcoholic fatty liver disease (NAFLD). NAFLD is the most common liver disorder world-wide and it has frequently been associated with obesity, hyperlipidemia and insulin resistance. Free fatty acids (FA) are the major mediators of hepatic steatosis; patients with NAFLD have elevated levels of circulating FA that correlate with disease severity.

METHODS

Steatosis is a reversible condition that can be resolved with changed behaviors, or that can progress towards more severe liver damages such as steatohepatitis (NASH), fibrosis and cirrhosis. In NAFLD, FA of exogenous or endogenous origin accumulate in the hepatocytes and trigger liver damages. Excess TG are stored in cytosolic lipid droplets (LDs) that are dynamic organelles acting as hubs for lipid metabolism.

RESULTS

In the first part of this review, we briefly reassumed the main classes of FA and their chemical classification as a function of the presence and number of double bonds, their metabolic pathways and effects on human health. Then, we summarized the main genetic and diet-induced animal models of NAFLD, as well as the cellular models of NAFLD.

CONCLUSIONS

In recent years, both the diet-induced animal models of NAFLD as well as the cellular models of NAFLD have found ever more application to investigate the mechanisms involved in NAFLD, and we referred to their advantages and disadvantages.

Perinatal and postweaning diets high in omega-3 fatty acids have age- and sex-specific effects on the fatty acid composition of the cerebellum and brainstem of C57BL/6 mice

The sex- and age-specific effects of omega (n)-3 polyunsaturated fatty acids (PUFA) enriched diets on brainstem and cerebellar fatty acid composition, and the expression of stearoyl-CoA desaturase (SCD)-1 and myelin basic protein (MBP) were investigated in C57BL/6 mice. Female mice were fed diets (20% fat, w/w) high or low in n-3 PUFA before mating, during pregnancy and lactation; and offspring (both males and females) were weaned onto their mother's designated diet for 16 weeks. A diet high in n-3 PUFA caused an accretion of docosahexaenoic acid in the cerebellum. Monounsaturated fatty acids increased from weaning to 16 weeks in the cerebellum. The changes in the cerebellar fatty acids were more pronounced in females, with a significant effect of diet. A diet high in n-3 PUFA increased cerebellar SCD-1 and MBP mRNA expression. These findings are novel and demonstrate that the effects of n-3 PUFA are brain region, age- and sex-specific.

Endogenous production of n-3 long-chain PUFA from first feeding and the influence of dietary linoleic acid and the α-linolenic:linoleic ratio in Atlantic salmon (Salmo salar)

Atlantic salmon (Salmo salar) possess enzymes required for the endogenous biosynthesis of n-3 long-chain PUFA (LC-PUFA), EPA and DHA, from α-linolenic acid (ALA). Linoleic acid (LA) competes with ALA for LC-PUFA biosynthesis enzymes leading to the production of n-6 LC-PUFA, including arachidonic acid (ARA). We aimed to quantify the endogenous production of EPA and DHA from ALA in salmon fed from first feeding on diets that contain no EPA and DHA and to determine the influence of dietary LA and ALA:LA ratio on LC-PUFA production. Salmon were fed from first feeding for 22 weeks with three diets formulated with linseed and sunflower oils to provide ALA:LA ratios of approximately 3:1, 1:1 and 1:3. Endogenous production of n-3 LC-PUFA was 5·9, 4·4 and 2·8 mg per g fish and that of n-6 LC-PUFA was 0·2, 0·5 and 1·4 mg per g fish in salmon fed diets with ALA:LA ratios of 3:1, 1:1 and 1:3, respectively. The ratio of n-3:n-6 LC-PUFA production decreased from 27·4 to 2·0, and DHA:EPA ratio increased and EPA:ARA and DHA:ARA ratios decreased, as dietary ALA:LA ratio decreased. In conclusion, with a dietary ALA:LA ratio of 1, salmon fry/parr produced about 28 μg n-3 LC-PUFA per g fish per d, with a DHA:EPA ratio of 3·4. Production of n-3 LC-PUFA exceeded that of n-6 LC-PUFA by almost 9-fold. Reducing the dietary ALA:LA ratio reduced n-3 LC-PUFA production and EPA:ARA and DHA:ARA ratios but increased n-6 LC-PUFA production and DHA:EPA ratio.

Validation of a Food Frequency Questionnaire to Assess Intake of n-3 Polyunsaturated Fatty Acids in Switzerland

Population-based data suggest that high intake of omega-3 (n-3) polyunsaturated fatty acids (PUFA) may be beneficial in a variety of health conditions. It is likely that mainly those patients with preexisting n-3 deficiency are those that benefit most from n-3 fatty acid supplementation. Therefore, for targeted interventions, a fast and reliable screening tool for n-3 PUFA intake is necessary. Thus, the aim of this project was to adapt and validate a food frequency questionnaire (FFQ) for n-3 PUFA intake in Switzerland while using as references the following: (1) 7-day food records (FR), and (2) n-3 fatty acid composition of red blood cells (RBC). We recruited 46 healthy adults for the first part of the study and 152 for the second. We used the dietary software EBISpro for the analysis of n-3 PUFA intake. RBC fatty acid composition was determined by gas chromatography mass spectrometry (GC-MS). Using correlation analysis, we found a moderate significant association between FFQ and FR for α-linolenic acid (ALA), eicosapentanoic acid (EPA), docosahexanoic acid (DHA), and total n-3 fatty acids (all r between 0.523 and 0.586, all p < 0.001). Bland Altman analysis further showed good agreement between the two methods and no proportional bias. Correlations between FFQ and RBC fatty acid composition were also moderate for EPA and DHA (r = 0.430 and r = 0.605, p < 0.001), but weaker for ALA and total n-3 (r = 0.314 and r = 0.211, p < 0.01). The efficacy of the FFQ to classify individuals into the same or adjacent quartile of RBC PUFA content ranged between 70% and 87% for the different fatty acids. In conclusion, we showed that the Swiss n-3 PUFA FFQ is a valid tool to assess dietary n-3 PUFA intake, especially DHA and EPA, to determine population groups at risk for low intake.

Adding heat-treated rapeseed to the diet of yak improves growth performance and tenderness and nutritional quality of the meat

Heat-treated rapeseed was supplemented to indoor fed yaks in winter to test the effect on dry matter intake (DMI), body mass change, and meat quality. Sixteen 3-year-old yak steers (124 ± 15.3 kg) were divided randomly into two groups and were offered either heat-treated rapeseed (HTR) or rapeseed meal (CONT). The yaks were allowed 14 days for adjustment and measurements were made over 120 d. There was no difference in DMI between groups (p = 0.67), but average daily gain tended to be higher (p < 0.056) and feed to gain ratio tended to be lower (p = 0.050) in HTR than in CONT yaks. Meat from HTR yaks was more tender (p = 0.006), had higher intramuscular fat (p = 0.013), and had lower cholesterol content (p = 0.009) than from CONT yaks. In addition, the atherogenic index was lower (0.37 vs. 0.43; p = 0.049), the PUFA:SFA ratio was higher (0.55 vs. 0.37; p = 0.049), and the n-6:n-3 (n-6 PUFA to n-3 PUFA) ratio was lower (2.76 vs. 4.78; p = 0.003) in HTR than in CONT yaks, which all favoured the HTR yaks. Meat from HTR yaks met human health standards of a PUFA:SFA ratio of above 0.4 and n-6:n-3 ratio of less than 4, whereas meat from CONT yaks just missed these standards.