The omega-6/omega-3 ratio is of importance!

Assessment of components related to flavor and taste in Tan-lamb meat under different silage-feeding regimens using integrative metabolomics

Two untargeted metabolomics approaches based on gas chromatography mass spectrometry and ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry were used to identify the effects of different feeding regimes (concentrate, corn silage, alfalfa silage, mulberry leaf silage) on the potential meat flavor and taste components of Tan-lamb. Among 31 identified volatiles, hexanal was affected by the alfalfa silage diet, and 3-hydroxydodecanoic acid was changed by the mulberry leaf silage diet. l-Pipecolic acid (area under the curve = 1, fold change = 0.18-0.48) and trimethylamine N-oxide (area under the curve = 1, fold change = 5.26-22.84) was the potential best discriminant biomarker under alfalfa silage and concentrate feeding, respectively. The hydrophilic components were more readily changed by feeding regimes than volatile flavor compounds. Our findings are helpful for the illustration of Tan-lamb meat chemistry and producing high-quality lamb meat with improved flavor and taste by corn silage, alfalfa silage, or mulberry leaf silage.

Serum ω-6/ω-3 polyunsaturated fatty acids ratio and diabetic retinopathy: A propensity score matching based case-control study in China

BACKGROUND

Optimal ω-6/ω-3 polyunsaturated fatty acids ratio (PUFAR) is reported to exert protective effects against chronic diseases. However, data on PUFAR and diabetic retinopathy (DR) remains scarce. We aimed to thoroughly quantify whether and how PUFAR was related to DR as well as its role in DR detection.

METHODS

This two-centre case-control study was conducted from August 2017 to June 2018 in China, participants were matched using a propensity score matching algorithm. We adopted multivariable logistic regression models and restricted cubic spline analyses to estimate the independent association of PUFAR with DR, adjusting for confounders identified using a directed acyclic graph. The value of PUFAR as a biomarker for DR identification was further evaluated by receiver operating characteristic analyses and Hosmer-Lemeshow tests.

FINDINGS

An apparent negative relationship between PUFAR and DR was observed. Adjusted odds of DR decreased by 79% (OR: 0·21, 95% CI: 0·10-0·40) with an interquartile range increase in PUFAR. Similar results were also obtained in tertile analysis. As compared to those in the 1st tertile of PUFAR, the adjusted odds of DR decreased by 76% (OR: 0·24, 95% CI: 0·08-0·66) and 93% (OR: 0·07, 95% CI: 0·03-0·22) for subjects in the 2nd and 3rd tertiles, respectively. Good calibration and discrimination of the PUFAR associated predictive model were detected and PUFAR = 35 would be an ideal cut-off value for DR identification.

INTERPRETATION

Our results suggest that serum PUAFR is inversely associated with DR. Although PUFAR-alteration is not observed amongst different stages of DR, it can serve as an ideal biomarker in distinguishing patients with DR from those without DR.

FUNDING

This study was funded by Natural Science Foundation of Zhejiang Province, Zhejiang Basic Public Welfare Research Project, the Major Project of the Eye Hospital of Wenzhou Medical University, and the Academician's Science and Technology Innovation Program in Zhejiang province. Part of this work was also funded by the National Nature Science Foundation of China, and Research Project for College Students in Wenzhou Medical University.

Association of n-6 PUFAs with the risk of diabetic retinopathy in diabetic patients

Diabetic retinopathy (DR), the most common microvascular complication of diabetes and leading cause of visual impairment in adults worldwide, is suggested to be linked to abnormal lipid metabolism. The present study aims to comprehensively investigate the relationship between n-6 polyunsaturated fatty acids (PUFAs) and DR. This was a propensity score matching based case-control study, including 69 pairs of DR patients and type 2 diabetic patients without DR with mean age of 56.7 ± 9.2 years. Five n-6 PUFAs were determined by UPLC-ESI-MS/MS system. Principle component regression (PCR) and multiple conditional logistic regression models were used to investigate the association of DR risk with n-6 PUFAs depending on independent training and testing sets, respectively. According to locally weighted regression model, we observed obvious negative correlation between levels of five n-6 PUFAs (linoleic acid, γ-linolenic acid, eicosadienoic acid, dihomo-γ-linolenic acid and arachidonicacid) and DR. Based on multiple PCR model, we also observed significant negative association between the five n-6 PUFAs and DR with adjusted OR (95% CI) as 0.62 (0.43,0.87). When being evaluated depending on the testing set, the association was still existed, and PCR model had excellent classification performance, in which area under the curve (AUC) was 0.88 (95% CI: 0.78, 0.99). In addition, the model also had valid calibration with a non-significant Hosmer-Lemeshow Chi-square of 9.44 (P = 0.307) in the testing set. n-6 PUFAs were inversely associated with the presence of DR, and the principle component could be potential indicator in distinguishing DR from other T2D patients.

Meat differentiation between pasture-fed and concentrate-fed sheep/goats by liquid chromatography quadrupole time-of-flight mass spectrometry combined with metabolomic and lipidomic profiling

Animal feeding method is a crucial factor in influencing meat quality. Consumers would preferentially select meat obtained from pasture-fed animals. In this study, an untargeted metabolomic and lipidomic method based on ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) combined with chemometric analysis was utilized to investigate the differences between meat from free-range and intensively-fed sheep/goats. Distinct separation between these two kinds of sheep/goats meat obtained were identified by principal component analysis. Analysis of variance, fold change and orthogonal projection to latent structures discriminant analysis were then conducted to determine specific potential markers. A total of 46 potential markers were selected according to online chemical databases. The support vector machine (SVM) method was used to process the responses of the selected potential markers, and the results of metabolomics and lipidomics from an additional 59 samples revealed the discrimination rate of 89.3% and 98.3%. These findings provided a basis for differentiation of meat from sheep/goats fed in the two methods.

Volatile Organic Compound and Fatty Acid Profile of Milk from Cows and Buffaloes Fed Mycorrhizal or Nonmycorrhizal Ensiled Forage

Seed inoculation of forage crops by arbuscular mycorrhizal fungi (AMF) generally results in higher profitability, but also modifies the chemical composition of silage in terms of increased biomass, protein, and dry matter. Raw milk aroma is affected by the type of feed. This work investigated the influence of ensiled forage obtained by seed inoculation with AMF on the volatile fractions and fatty acid composition of milk. Two experiments were carried out: in the first, buffaloes were fed maize silage, and in the second, cows were fed sorghum silage. The volatile fractions of milk were quantified by headspace solid-phase micro-extraction (HS-SPME), combined with gas chromatography-mass spectrometry (GC-MS), and fatty acids by gas chromatography (GC). The ensiled forage obtained with AMF increased saturated fatty acids (SFAs), and decreased monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) in both experiments. The volatile fraction in milk samples obtained from bovines fed mycorrhizal ensiled forage showed an increase of free fatty acids and ketones, responsible for cheesy and fruity odors. Aldehydes, responsible for green and grassy notes, increased only in the milk from buffaloes fed ensiled maize. Our results suggest that inoculation of maize and sorghum seed with AMF, combined with a low rate of fertilizers, leads to ensiled forage that could slightly affect the FA profile and odor quality of milk.

Serum n-6 and n-9 Fatty Acids Correlate With Serum IGF-1 and Growth Up to 4 Months of Age in Healthy Infants

OBJECTIVE

The aim of this study was to study the relationship between insulin-like growth factor-1 (IGF-1), serum phospholipid fatty acids, and growth in healthy full-term newborns during infancy.

METHODS

Prospective observational study of a population-based Swedish cohort comprising 126 healthy, term infants investigating cord blood and serum at 2 days and 4 months of age for IGF-1 and phospholipid fatty acid profile and breast milk for fatty acids at 2 days and 4 months, compared with anthropometric measurements (standard deviation scores).

RESULTS

At all time-points arachidonic acid (AA) was negatively associated with IGF-1. IGF-1 had positive associations with linoleic acid (LA) at 2 days and 4 months and mead acid (MA) showed positive associations in cord blood. Multiple regression analyses adjusted for maternal factors (body mass index, weight gain, smoking, education), sex, birth weight and feeding modality confirmed a negative association for the ratio AA/LA to IGF-1. MA in cord blood correlated to birth size. Changes in the ratios of n-6/n-3 and AA/docosahexaenoic acid from day 2 to 4 months together with infants' weight and feeding modality determined 55% of the variability of delta-IGF-1. Breast-fed infants at 4 months had lower IGF-1 correlating with lower LA and higher AA concentrations, which in girls correlated with lower weight gain from birth to 4 months of age.

CONCLUSIONS

Our data showed interaction of n-6 fatty acids with IGF-1 during the first 4 months of life, and an association between MA and birth size when adjusted for confounding factors. Further follow-up may indicate whether these correlations are associated with later body composition.

Personalized polyunsaturated fatty acids as a potential adjunctive treatment for anorexia nervosa

Anorexia nervosa (AN) is a complex psychiatric disorder with high morbidity and mortality rates. While many individuals make full recoveries, up to a third of patients develop a chronic, treatment-resistant form of the illness that leads to a premature death in 15-20% of those affected. There have been few advances in treatment, both in terms of psychological or pharmacologic treatment over the last 30 years. Food aversion is commonly cited by patients with AN as a barrier to normalizing eating and weight. Our group has a keen interest in examining factors that might allow this to be addressed, thus improving treatment outcomes through personalized dietary plans or nutritional supplementation related to underlying genetic status. We demonstrated that polyunsaturated fatty acids (PUFAs)-derived bioactive lipids (eicosanoids) are implicated in not only the risk of AN, but also with its comorbid psychopathology. Of interest, the differential postprandial omega 6-derived eicosanoid shift observed in AN highlights the possibility that the metabolism of PUFAs is an important mechanism underlying the profound food version, contributing to pathological food restriction in AN. A concise knowledge of the relationships among PUFAs, eicosanoids, and AN clinical course and psychopathology could be the key to developing personalized nutritional rehabilitative treatments for those suffering from AN. This paper provides a comprehensive overview of the literature on PUFAs in AN. We also selectively reviewed the clinical benefits PUFA treatments exert in other psychiatric diseases, on weight and appetite regulation, and for resolution of inflammation, all of which are relevant in the disease course and outcome of AN. We propose that personalized PUFA formulation be developed and tested as a novel adjunctive treatment for patients with AN. We hypothesize that with personalized PUFA formulation, food aversion and anxiety about eating will decrease while mood, dietary behavior, and weight restoration will improve in AN, leading to improvements in the overall treatment outcome.

Effects of microalgal polyunsaturated fatty acid oil on body weight and lipid accumulation in the liver of C57BL/6 mice fed a high fat diet

Dietary polyunsaturated fatty acids (PUFAs), which are abundant in marine fish oils, have recently received global attention for their prominent anti-obesogenic effects. Among PUFAs, eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3), which are n-3 long-chain PUFAs widely referred to as omega-3 oils, were reported to prevent the development of obesity in rodents and humans. In the present study, we evaluated the anti-obesity effects of microalgal oil on high-fat induced obese C57BL/6 mice, compared with commercial omega-3 fish oil and vegetable corn oil. Microalgal oil is an inherent mixture of several PUFAs, including EPA, DHA and other fatty acids produced from a marine microalgal strain of Thraustochytriidae sp. derived mutant. It was found to contain more PUFAs (>80%) and more omega-3 oils than commercial omega-3 fish oil (PUFAs >31%) and corn oil (PUFAs 59%). All three types of oils induced weight loss in high-fat-induced obese mice, with the loss induced by microalgal oil being most significant at 9 weeks (10% reduction). However, the oils tested did not improve blood lipid levels, although microalgal oil showed an apparent inhibitory effect on lipid accumulation in the liver. These findings may be attributed to the higher PUFA content, including omega-3 oils of microalgal oil than other oils. Collectively, these findings suggest that microalgal oil, derived from Thraustochytriidae sp. derived mutant, is a prominent candidate for replacement of omega-3 fish oils based on its apparent anti-obesity effect in vivo.