Implication of conjugated linoleic acid (CLA) in human health

Effects of soybean oil supplementation on performance, digestion and metabolism of early lactation dairy cows fed sugarcane-based diets

Sugarcane is an important forage source for dairy cows in tropical countries. However, it provides limited digestible fiber and energy intake, and fat supplementation can be a way to increase energy density and decrease dietary, non-fiber carbohydrates concentrations. We aimed to evaluate the performance, digestion and metabolism of dairy cows in early lactation fed different concentrations of soybean oil (SBO) in sugarcane-based diets. Fourteen primiparous (545±17.2 kg of BW) and eight multiparous (629±26.7 kg BW) Holstein dairy cows were used according to a randomized block design. After calving, diets were randomly assigned to cows within the two parity groups. Diets were formulated with increasing concentrations of SBO (g/kg dry matter (DM)): control (0), low (LSBO; 15.7), medium (MSBO; 44.3) and high (HSBO; 73.4). The study was performed from calving until 84 days in milk, divided into three periods of 28 days each. Dry matter intake (DMI) was affected quadratically in response to SBO addition with the greatest and lowest values of 19.0 and 16.0 kg/day for LSBO and HSBO diets, respectively. The digestibility of potentially digestible NDF was quadratically affected by SBO with the greatest value of 623 g/kg for LSBO diet. Both milk and energy-corrected milk (ECM) production were quadratically affected by SBO inclusion, with greatest ECM values of 27.9 and 27.3 for LSBO and MSBO, respectively. Soybean oil inclusion linearly decreased milk fat concentration by 13.2% from control to HSBO. The CLA t10,c12-18:2 was observed in milk fat only for MSBO and HSBO diets. Soybean oil inclusion did not affect plasma glucose or serum concentrations of total proteins, globulins, albumin, urea nitrogen, beta-hydroxybutyrate, non-esterified fatty acids or insulin. Serum concentrations of total cholesterol, triglycerides and low-density lipoprotein increased with SBO supplementation. Soybean oil inclusion in sugarcane-based diets for early lactation dairy cows from 15.7 to 44.3 g/kg DM can improve energy intake and performance; however, at 44.3 g/kg DM milk fat concentration and ECM decreased. Soybean oil inclusion at 73.4 g/kg DM adversely affected energy intake, fiber digestion and performance of early lactation dairy cows and is not recommended.

Conjugated Linoleic Acid Regulates Body Composition and Locomotor Activity in a Sex-Dependent Manner in Drosophila melanogaster

Conjugated linoleic acid (CLA) has been reported to be a bioactive food component. However, there is limited knowledge on the sex-dependent effects of CLA on energy metabolism. In the present study, Drosophila melanogaster was used to investigate the sex-dependent effects of CLA with respect to body fat, muscle, locomotion, and a key metabolic regulator, AMP-activated protein kinase α (AMPKα). Adult flies were fed a cornmeal-based fly food with 0.5% of CLA oil (50:50 of cis-9,trans-11 and trans-10,cis-12 CLA isomers in triacylglycerol (TAG) form), 0.5% safflower oil (high in linoleic acid [LNA] as control), or 0.5% water (as blank) for 5 days. Accumulation of CLA in tissue was verified using gas chromatography-mass spectrometry. CLA-fed flies had reduced TAG and increased locomotor activity when compared to LNA-fed control flies. In addition, CLA increased the muscle content when compared to the blank. Moreover, following CLA supplementation, increased AMPKα activity was observed in females, but not in males. These sex-dependent metabolic effects of CLA may be due to physiological differences in lipid metabolism and nutrient requirements. In conclusion, CLA promoted the body composition and locomotion behavior in D. melanogaster and regulated the sex-specific metabolism in part via AMPKα. As key physiological processes are conserved between fly and human, information obtained from this research could provide valuable insights into sex-dependent responses to CLA in humans.

Special-Fed Veal: Separable components, proximate composition, and nutrient analysis of selected raw and cooked, wholesale and retail cuts

Nutrition research continues to be important for consumers to make informed food purchasing decisions and is used in nutrition policy decisions. The objective of this study was to analyze the nutrient concentration of raw and cooked cuts from special-fed veal calves to update nutrient data in the USDA National Nutrient Database for Standard Reference (SR) Release 27. Packages of wholesale (whole loin roasts, center-cut hindshanks and ground veal) and retail veal cuts (osso buco foreshanks, loin chops, leg cutlets and shoulder blade chops) were randomly collected in original vacuum packaging from six U.S. suppliers. Packages were shipped to the Colorado State University Meat Laboratory for cut dissection, cooking, and nutrient analysis. Composites of lean, external fat and seam fat were formed for analysis of proximate, fatty acid, vitamin and mineral composition. Results from this study identified additional fatty acids, established choline concentration, and provided updated veal nutrient composition information for inclusion in USDA SR 27.

The Growth-Inhibiting Effects of Beef Fatty Acids on MCF-7 Cells Are Influenced Mostly by the Depot Location and Inconsistently by the Biohydrogenation Intermediate Content

Biohydrogenation intermediates (BHI) including conjugated linoleic acid (CLA) isomers are formed during ruminal biohydrogenation of polyunsaturated fatty acids (PUFA) in ruminants. Although many studies have examined the anticarcinogenic effects of CLA, few studies have reported the anticarcinogenic properties of BHI in their natural form found in dairy and beef fats. The present study compared the growth-inhibitory effects of fatty acids from beef perirenal fat (PRF) or subcutaneous fat (SCF) with low or high levels of BHI in MCF-7 human breast cancer cells. Cells were exposed for 72 h to media containing increasing doses (50 to 400 μM) of different beef fat treatments. Fatty-acid analysis showed that BHI were readily incorporated into cell phospholipids (PL) in a treatment-dependent manner, but higher BHI in PL did not consistently inhibit growth. Culturing with low-BHI PRF or high-BHI PRF did not lead to growth inhibition, but low-BHI SCF inhibited growth, and inhibition was further increased by high-BHI SCF. Other classes of fatty acids may, therefore, be interacting with BHI resulting in differential effects on growth inhibition in human breast cancer cells.

Effect of substituting fresh-cut perennial ryegrass with fresh-cut white clover on bovine milk fatty acid profile

BACKGROUND

Including forage legumes in dairy systems can help address increasing environmental/economic concerns about perennial ryegrass monoculture pastures. This work investigated the effect of substituting fresh-cut grass with increasing quantities of fresh-cut white clover (WC) on milk fatty acid (FA) profile and transfer efficiency of dietary linoleic (LA) and α-linolenic (ALNA) acids to milk fat. Three groups of three crossbred dairy cows were used in a 3 × 3 crossover design. Dietary treatments were 0 g kg^-1 WC + 600 g kg^-1 grass, 200 g kg^-1 WC + 400 g kg^-1 grass, and 400 g kg^-1 WC + 200 g kg^-1 grass. All treatments were supplemented with 400 g kg^-1 concentrates on a dry matter basis. Cows had a 19-day adaptation period to the experimental diet before a 6-day measurement period in individual tie stalls.

RESULTS

Increasing dietary WC did not affect dry matter intake, milk yield or milk concentrations of fat, protein or lactose. Milk polyunsaturated FA concentrations (total n-3, total n-6, LA and ALNA) and transfer efficiency of LA and ALNA were increased with increasing dietary WC supply.

CONCLUSION

Inclusion of WC in pastures may increase concentrations of nutritionally beneficial FA, without influencing milk yield and basic composition, but any implications on human health cannot be drawn. © 2018 The Authors. Journal of the Science of Food and Agriculture published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry.

Composição de ácidos graxos do queijo e leite de vacas alimentadas com casca de banana

RESUMO Objetivou-se avaliar os níveis de casca de banana seca ao sol na dieta de vacas F1 Holandês x Zebu sobre o perfil de ácidos graxos do leite e do queijo minas frescal. Os tratamentos foram constituídos de 0, 15, 30, 45 e 60% de substituição da silagem de sorgo pela casca de banana. O delineamento experimental foi em dois quadrados latinos 5 x 5 simultâneos. As amostras de leite e queijo foram analisadas quanto ao perfil de ácidos graxos por cromatografia gasosa. Observou-se efeito quadrático para o somatório de ácidos graxos poli-insaturados do leite, com valor máximo no nível de 23,54% de substituição. Houve efeito linear decrescente para os ácidos graxos C15:0 iso e C16:0 iso. Os ácidos graxos heneicosanoico, linoleico, linoleico conjugado e araquidônico apresentaram efeito quadrático. Não houve efeito das dietas sobre os ácidos graxos no queijo. A substituição de até 60% da silagem de sorgo por casca de banana na dieta de vacas em lactação pode ser alternativa para produção e processamento do leite, quando se considera a melhora no valor nutricional da fração lipídica do leite e o aumento dos teores de ácido linoleico conjugado.

Co-administration of conjugated linoleic acid and rosiglitazone increases atherogenic co-efficient and alters isoprenaline-induced vasodilatation in rats fed high fat diet

The cis(c)-9, trans(t)-11 (c9,t11) and t10,c12 isomers of conjugated linoleic acid (CLA) have been reported as agonists of peroxisome proliferator-activated receptor (PPAR) and beneficial in lipidemia and glycemia. However, it is unclear whether CLA isomers enhance or antagonize effects of conventional drugs targeting PPAR. Male Sprague-Dawley rats were fed high fat diet (HFD) for 8 weeks and treated without or with CLA, rosiglitazone or both for 4 weeks. Oral glucose tolerance and surrogate markers of insulin resistance were not significantly different for all treatments compared to untreated normal diet (ND) or HFD group, except lipoprotein levels. The combination of CLA and rosiglitazone had suppressed levels of low and high density lipoproteins (46 % and 25 %, respectively), compared to HFD-alone. Conversely, the atherogenic co-efficient of the animals received HFD or HFD+rosiglitazone+CLA was 2-folds higher than ND, HFD+rosiglitazone or HFD+CLA. Isolated aortic rings from the combined CLA and rosiglitazone treated animals were less sensitive to isoprenaline-induced relaxation among endothelium-denuded aortas with a decreased efficacy and potency (R(max)=53+/-4.7 %; pEC50=6+/-0.2) compared to endothelium-intact aortas (R(max)=100+/-9.9 %; pEC50=7+/-0.2). Our findings illustrate that the combination of CLA and rosiglitazone precede the atherogenic state with impaired endothelium-independent vasodilatation before the onset of HFD-induced insulin resistance.

Conjugated linoleic acid prevents damage caused by intestinal mucositis induced by 5-fluorouracil in an experimental model

BACKGROUND

Studies have showed the protective effects of conjugated linoleic acid (CLA) on intestinal epithelium, modulating host immune and inflammatory responses on intestinal diseases.

OBJECTIVE

To evaluate the preventive effects of CLA on the intestinal mucositis induced by 5-FU in a murine model.

METHODS

Sixty-four BALB/c mice were randomly divided into four groups: Control (CTL), fed a standard chow diet; CLAs, fed a diet supplemented with CLA; Mucositis (5-FU), fed a standard chow diet and underwent mucositis induction and CLAs 5-FU, fed a diet supplemented with CLA and underwent mucositis induction. Mucositis was induced by intraperitoneal injection of 300 mg/kg 5-FU. After 72 h, the animals were euthanized and intestinal permeability, bacterial translocation, inflammatory mediators, and intestinal histology were evaluated.

RESULTS

Mice in the CLAs 5-FU group showed reduced weight loss compared to those in the 5-FU group (p < 0.005). Furthermore, the results also showed that the treatment with CLA reduced intestinal permeability, bacterial translocation, and biomarkers of inflammatory response besides minor damage to ZO-1 and occludin with maintenance of the integrity of the intestinal epithelium and a favorable balance between the inflammatory and regulatory cytokines.

CONCLUSION

This study suggests that CLA reduced the adverse effects from 5-FU administration on the intestinal mucosa.

Enhancing the fatty acid profile of milk through forage-based rations, with nutrition modeling of diet outcomes

Consumer demand for milk and meat from grass-fed cattle is growing, driven mostly by perceived health benefits and concerns about animal welfare. In a U. S.-wide study of 1,163 milk samples collected over 3 years, we quantified the fatty acid profile in milk from cows fed a nearly 100% forage-based diet (grassmilk) and compared it to profiles from a similar nationwide study of milk from cows under conventional and organic management. We also explored how much the observed differences might help reverse the large changes in fatty acid intakes that have occurred in the United States over the last century. Key features of the fatty acid profile of milk fat include its omega-6/omega-3 ratio (lower is desirable), and amounts of total omega-3, conjugated linoleic acid, and long-chain omega-3 polyunsaturated fatty acids. For each, we find that grassmilk is markedly different than both organic and conventional milk. The omega-6/omega-3 ratios were, respectively, 0.95, 2.28, and 5.77 in grassmilk, organic, and conventional milk; total omega-3 levels were 0.049, 0.032, and 0.020 g/100 g milk; total conjugated linoleic acid levels were 0.043, 0.023, and 0.019 g/100 g milk; and eicosapentaenoic acid levels were 0.0036, 0.0033, and 0.0025 g/100 g milk. Because of often high per-capita dairy consumption relative to most other sources of omega-3 fatty acids and conjugated linoleic acid, these differences in grassmilk can help restore a historical balance of fatty acids and potentially reduce the risk of cardiovascular and other metabolic diseases. Although oily fish have superior concentrations of long-chain omega-3 fatty acids, most fish have low levels of α-linolenic acid (the major omega-3), and an omega-6/omega-3 ratio near 7. Moreover, fish is not consumed regularly, or at all, by ~70% of the U. S.

POPULATION

Comparison of methylation methods for fatty acid analysis of milk fat

Three acid- and alkaline-catalysed transesterification methods were compared with the aim to validate a simple yet reliable protocol for fatty acid (FA) profiling of milk fat. While both the acid- and alkaline-catalysed methods were able to convert completely triglycerides and phospholipids into fatty acid methyl esters (FAMEs), the acid catalyst caused significant degradation of conjugated linoleic acid C18:2c9t11 at high temperature. Although a milder temperature can mitigate this negative impact, a long reaction time (2 h) is required to achieve full methylation. By contrast, despite being unable to methylate free fatty acids (FFA), the alkaline-catalysed transesterification yielded comparable results for all major FA due to the very low level of FFA in milk. The alkaline-catalysed methylation is benign for C18:2c9t11. We recommend here a simple one-step protocol based on 0.2 M methanolic KOH, a short reaction time (20 min) and a mild reaction temperature (50 °C) for milk FAME preparation.

Adaptations of Skeletal Muscle Mitochondria to Obesity, Exercise, and Polyunsaturated Fatty Acids

Mitochondria intricately modulate their energy production through the control of mitochondrial adaptation (mitochondrial biogenesis, fusion, and/or fission) to meet energy demands. Nutrient overload may result in dysregulated mitochondrial biogenesis, morphology toward mitochondrial fragmentation, and oxidative stress in the skeletal muscle. In addition, physical activity and diet components influence mitochondrial function. Exercise may stimulate mitochondrial biogenesis and promote mitochondrial fusion/fission in the skeletal muscle. Moreover, some dietary fatty acids, such as n-3 polyunsaturated fatty acids and conjugated linoleic acid, have been identified to positively regulate mitochondrial adaptation in the skeletal muscle. This review discusses the association of mitochondrial impairments and obesity, and presents an overview of various mechanisms of which exercise training and mitochondrial nutrients promote mitochondrial function in the skeletal muscle.

UV Lamp as a Facile Ozone Source for Structural Analysis of Unsaturated Lipids Via Electrospray Ionization-Mass Spectrometry

Ozonolysis of alkene functional groups is a type of highly specific and effective chemical reaction, which has found increasing applications in structural analysis of unsaturated lipids via coupling with mass spectrometry (MS). In this work, we utilized a low-pressure mercury lamp (6 W) to initiate ozonolysis inside electrospray ionization (ESI) sources. By placing the lamp near a nanoESI emitter that partially transmits 185 nm ultraviolet (UV) emission from the lamp, dissolved dioxygen in the spray solution was converted into ozone, which subsequently cleaved the double bonds within fatty acyls of lipids. Solvent conditions, such as presence of water and acid solution pH, were found to be critical in optimizing ozonolysis yields. Fast (on seconds time scale) and efficient (50%-100% yield) ozonolysis was achieved for model unsaturated phospholipids and fatty acids with UV lamp-induced ozonolysis incorporated on a static and an infusion nanoESI source. The method was able to differentiate double bond location isomers and identify the geometry of the double bond based on yield. The analytical utility of UV lamp-induced ozonolysis was further demonstrated by implementation on a liquid chromatography (LC)-MS platform. Ozonolysis was effected in a flow microreactor that was made from ozone permeable tubing, so that ambient ozone produced by the lamp irradiation could diffuse into the reactor and induce online ozonolysis post-LC separation and before ESI-MS. Graphical Abstract ᅟ.

Improvement of nutritional components and in vitro antioxidative properties of soy-powder yogurts using Lactobacillus plantarum

This research was the first to demonstrate changes in nutritional compositions (isoflavone and CLA) from the 50% methanol extracts of soy-powder milk (SPM) and soy-powder yogurt (SPY) through fermentation using Lactobacillus plantarum S48 and P1201 strains. The radical scavenging activities and protective effects against oxidative stress in LLC-PK₁ cells were also investigated. The average physicochemical characteristics including acidity and viable cell number as well as β-glucosidase activity increased with 0.2 → 0.7%, 7.5 → 9.8 log cfu/mL, and 0.0 3 → 1.75 U/g in SPYs. Total average isoflavones were considerably reduced (3180.3 → 2018.3 μg/g) with the increase of aglycone contents (191.8 → 770.2 μg/g), especially, daidzein exhibited the most remarkable increase rate (98.6 → 460.9 μg/g; > 4.8 times) during fermentation. The CLA and total phenolics also increased with significant differences (ND → 1.6 mg/g; 2.4 → 3.6 mg/GAE/g) between SPM and SPY. Interestingly, the cis-9, trans-11 CLA showed approximately 90% in total content. Moreover, the scavenging capacities against three radicals markedly increased with about 30% in SPYs, as the following order: ABTS > hydroxyl > DPPH. The protective effects on oxidative stress (py-rogallol: O2-, SNP: NO, and SIN-1: ONOO⁻) were also observed high cell viabilities (>10%) under LLC-PK₁ cellular system. Our results suggest that SPY may be utilized as a potent source regarding natural antioxidants and beneficial components for health food and medical uses.

Serum Conjugated Linoleic Acid and Risk of Incident Heart Failure in Older Men: The British Regional Heart Study

BACKGROUND

Evidence largely from animal studies suggests that conjugated linoleic acid (CLA) may have cardiovascular health benefits. However, few prospective studies have examined the association between CLA and cardiovascular disease. We have prospectively examined the association between serum CLA and incident coronary heart disease and heart failure (HF) in older men.

METHODS AND RESULTS

Prospective study of 3806 men, aged 60 to 79 years, without prevalent HF followed up for an average of 13 years, during which there were 295 incident HF cases. A high-throughput serum nuclear magnetic resonance metabolomics platform was used to measure CLA concentration in serum, expressed as a percentage of total fatty acids (CLA%). CLA% was adversely associated with cholesterol and high-density lipoprotein cholesterol but was inversely associated with C-reactive protein and NT-proBNP (N-terminal pro-B-type natriuretic peptide; a marker of ventricular stress). No association was seen between CLA% and incident coronary heart disease. High CLA% was associated with significantly reduced risk of HF after adjustment for HF risk factors and C-reactive protein (hazard ratio [95% confidence interval], 0.64 [0.43-0.96]; quartile 4 versus quartile 1). Elevated CLA% was associated with reduced HF risk only in those with higher dairy fat intake, a major dietary source of CLA (test for interaction P=0.03). The reduced risk of HF was partially explained by NT-proBNP. High dairy fat intake was not associated with incident coronary heart disease but was associated with reduced risk of HF, largely because of the inverse effect of CLA.

CONCLUSIONS

The finding that high CLA% is associated with lower risk of incident HF in older men requires confirmation in larger studies.

Milk from cows fed a diet with a high forage:concentrate ratio improves inflammatory state, oxidative stress, and mitochondrial function in rats

Excessive energy intake may evoke complex biochemical processes characterized by inflammation, oxidative stress, and impairment of mitochondrial function that represent the main factors underlying noncommunicable diseases. Because cow milk is widely used for human nutrition and in food industry processing, the nutritional quality of milk is of special interest with respect to human health. In our study, we analyzed milk produced by dairy cows fed a diet characterized by a high forage:concentrate ratio (high forage milk, HFM). In view of the low n-6:n-3 ratio and high content of conjugated linoleic acid of HFM, we studied the effects of this milk on lipid metabolism, inflammation, mitochondrial function, and oxidative stress in a rat model. To this end, we supplemented for 4 wk the diet of male Wistar rats with HFM and with an isocaloric amount (82 kJ, 22 mL/d) of milk obtained from cows fed a diet with low forage:concentrate ratio, and analyzed the metabolic parameters of the animals. Our results indicate that HFM may positively affect lipid metabolism, leptin:adiponectin ratio, inflammation, mitochondrial function, and oxidative stress, providing the first evidence of the beneficial effects of HFM on rat metabolism.

Conjugated linoleic acid does not affect digestion and absorption of fat and starch-a randomized, double-blinded, placebo-controlled parallel study

OBJECTIVE

Conjugated linoleic acid (CLA) is known as a potent agent for altering body weight and composition. However, its effect on the process of digestion is still unknown. The aim of this study has been to elucidate the effect of a 3-month supplementation with CLA on starch and fat digestion and absorption in humans.

APPROACH

The study included 74 obese and overweight adults who were randomized to receive 3.0 g of CLA or sunflower oil as placebo daily for 3 months. Digestion and absorption of fat and starch was assessed using non-invasive breath tests with a stable ¹³C isotope (cumulative percentage dose recovery, CPDR) before and after the supplementation period. To exclude the effect of oxidation, in addition total energy expenditure (TTE) was measured by a ¹³C bicarbonate breath test.

RESULTS

The changes in CPDR values (∆CPDR median 〈interquartile range〉) were no different between subjects from the CLA group and the placebo group (fat: -0.2 〈-9.1-4.1〉 versus 0.6 〈-7.0-8.0〉, p < 0.4796; starch: -1.3 〈-9.5-2.4〉 versus -1.0 〈-5.1-1.7〉, p < 0.5520, respectively). The incidence of negative and positive values of ∆CPDR was no different between groups [for fat: 53.1% versus 46.7%, RR 1.138, (95% CI 0.689-1.882) and for starch: 67.7% versus 56.7%, RR 1.195, (95% CI 0.804-1.777)]. The changes in TTE did not differ between the CLA and the placebo group (respectively 1 〈48; 267〉 versus -8 〈-120;93〉 kcal; p < 0.2728).

CONCLUSION

Supplementation with CLA for 3 months did not affect fat and starch digestion assessed by ¹³C mixed triglyceride breath test and ¹³C starch breath test.

Metabolic profiles of adipose-derived and bone marrow-derived stromal cells from elderly coronary heart disease patients by capillary liquid chromatography quadrupole time-of-flight mass spectrometry

Adipose-tissue derived mesenchymal stem cell (ADSC)-based therapy is a promising option for patients with atherosclerotic conditions, including coronary artery disease. However, the potential differences in the metabolic characteristics between bone marrow-derived mesenchymal stem cells (BMSCs) and ADSCs have remained to be fully elucidated. The present study aimed to compare the metabolic profiles of BMSCs and ADSCs via liquid chromatography quadrupole time-of-flight mass spectrometry. BMSCs and ADSCs obtained from elderly coronary heart disease patients were cultured, and after three passages, supernatants of each cell type were collected and systematically analysed. Substantial differences were detected between the metabolite signatures of ADSCs and BMSCs. In addition, further analysis using partial least-squares discriminant analysis score plots indicated significant differences between the supernatants of the two cell types. The following metabolites were deemed to be responsible for the potential differences in the metabolic characteristics of BMSCs and ADSCs: D-lactic acid, hydroxyindoleacetaldehyde, α-D-glucose, bovinic acid, 9,10-epoxyoctadecenoic acid, glyceraldehyde, phenylpyruvic acid, L-octanoylcarnitine, retinyl ester, α-ketoisovaleric acid, guanidoacetic acid, N-acetylneuraminic acid, imidazoleacetic acid riboside, sphingosine and pseudouridine 5′-phosphate. Based on these findings, there may be significant differences in the following metabolic pathways: The linoleic acid metabolic pathway, galactose metabolism, argentines and proline metabolism, retinol metabolism, glycine and serine metabolism, galactose metabolism, and amino sugar and nucleotide sugar metabolism. In conclusion, substantial differences in metabolic characteristics were detected between BMSCs and ADSCs, which may be associated with the different efficacies of atherosclerosis therapies employing these cell types.

High Resolution NMR Spectroscopy as a Structural and Analytical Tool for Unsaturated Lipids in Solution

Mono- and polyunsaturated lipids are widely distributed in Nature, and are structurally and functionally a diverse class of molecules with a variety of physicochemical, biological, medicinal and nutritional properties. High resolution NMR spectroscopic techniques including 1H-, 13C- and 31P-NMR have been successfully employed as a structural and analytical tool for unsaturated lipids. The objective of this review article is to provide: (i) an overview of the critical 1H-, 13C- and 31P-NMR parameters for structural and analytical investigations; (ii) an overview of various 1D and 2D NMR techniques that have been used for resonance assignments; (iii) selected analytical and structural studies with emphasis in the identification of major and minor unsaturated fatty acids in complex lipid extracts without the need for the isolation of the individual components; (iv) selected investigations of oxidation products of lipids; (v) applications in the emerging field of lipidomics; (vi) studies of protein-lipid interactions at a molecular level; (vii) practical considerations and (viii) an overview of future developments in the field.

Can we improve the nutritional quality of meat?

The nutritional value of meat is an increasingly important factor influencing consumer preferences for poultry, red meat and processed meat products. Intramuscular fat content and composition, in addition to high quality protein, trace minerals and vitamins are important determinants of nutritional value. Fat content of meat at retail has decreased substantially over the past 40 years through advances in animal genetics, nutrition and management and changes in processing techniques. Evidence of the association between diet and the incidence of human non-communicable diseases has driven an interest in developing production systems for lowering total SFA and trans fatty acid (TFA) content and enrichment of n-3 PUFA concentrations in meat and meat products. Typically, poultry and pork has a lower fat content, containing higher PUFA and lower TFA concentrations than lamb or beef. Animal genetics, nutrition and maturity, coupled with their rumen microbiome, are the main factors influencing tissue lipid content and relative proportions of SFA, MUFA and PUFA. Altering the fatty acid (FA) profile of lamb and beef is determined to a large extent by extensive plant and microbial lipolysis and subsequent microbial biohydrogenation of dietary lipid in the rumen, and one of the major reasons explaining the differences in lipid composition of meat from monogastrics and ruminants. Nutritional strategies can be used to align the fat content and FA composition of poultry, pork, lamb and beef with Public Health Guidelines for lowering the social and economic burden of chronic disease.

Could predicting fatty acid profile by mid-infrared reflectance spectroscopy be used as a method to increase the value added by milk production chains?

The aims of this work were (1) to develop prediction equations from mid-infrared spectroscopy (MIRS) to establish a detailed fatty acid (FA) composition of milk; (2) to propose a milk FA index, utilizing MIRS-developed equations, in which the precision of the FA-prediction equations is taken into account to increase the value of milk; and (3) to show application examples. A total of 651 bulk cow milk samples were collected from 245 commercial farms in northwest Italy. The results of the 651 gas chromatography analyses were used to establish (421 samples) and to validate (230 samples) the outcomes of the FA composition prediction that had been obtained by MIRS. A class-based approach, in which the obtained MIRS equations were used, was proposed to define a milk classification. The method provides a numerical index [milk FA index (MFAI)] that allows a premium price to be quantified to increase the value of a favorable FA profile of milk. Ten FA were selected to calculate MFAI, according to their relevance for human health and potential cheese sensory properties, and animal welfare and environmental sustainability were also considered. These factors were selected as dimensions of MFAI. A statistical analysis and expert judgment aggregation were performed on the selected FA by weighting the FA and normalizing the dimensions to reduce redundancy. A class approach was applied, using the precision of the MIRS equations to establish the classes. The median FA concentration of the data set was set as a reference value of class 0. The width, number, and limits of classes above and below the median were calculated using the 95% confidence level of the standard error of prediction, corrected with the bias of each FA. A progressive number and a positive or negative sign were assigned to each FA class above or below the median according to their role in the above mentioned dimensions. The sum of the numbers of each class, associated with its sign for each FA, was used to generate MFAI. The MFAI was applied to dairy farms characterized by different feeding strategies, all of which deliver milk to a commercial dairy plant. The MFAI values ranged from 0.7 to 4.2, and large variations, which depended on the cows' diet and forage quality, were observed for each feeding system. The proposed method has been found to be flexible and adaptable to several contexts on both intensive and extensive dairy farms.

Detailed fatty acid profile of milk, cheese, ricotta and by products, from cows grazing summer highland pastures

In this research two-dimensional GC was used to analyse, for the first time, the detailed fatty acid (FA) profiles of 11 dairy matrices: raw milk (evening whole, evening partially skimmed, morning whole, and vat milk), cream, fresh cheese, whey, ricotta, scotta, 6- and 12-month-ripened cheeses, obtained across artisanal cheese- and ricotta-making trials carried out during the summer period while cows were on highland pastures. Samples were collected during 7 cheese- and ricotta-making procedures carried out at 2-week intervals from bulk milk to study possible differences in the transfer and modification of FA. Compared with morning milk, evening milk had fewer de novo synthetised FA. The detailed FA profile of partially skimmed milk differed little from that of evening whole milk before skimming, but the cream obtained differed from partially skimmed milk and from fresh cheese in about half the FA, due mainly to higher contents of all de novo FA, and lower contents of n-3 and n-6 FA. Fresh cheese and whey had similar FA profiles. The ricotta manufacturing process affected the partition of FA between ricotta and scotta, the FA profile of the latter differing in terms of groups and individual FA from the former, whereas ricotta and fresh cheese had similar composition of FA. In general, there was an increase in medium-chain saturated FA, and a decrease in many polyunsaturated FA during the first 6 months of ripening, but not during the second 6 months. Two-dimensional GC yielded a very detailed and informative FA profile on all the 11 dairy products and by-products analysed.

Dietary supplementation with dried olive pomace in dairy cows modifies the composition of fatty acids and the aromatic profile in milk and related cheese

This study aimed to evaluate the effect of dietary integration of dried olive pomace (DOP), a by-product of olive oil separation, on nutritional and aromatic properties of milk and cheese. Twenty dairy cows were divided into 2 groups that were balanced for milk yield, parity, and days in milk. The control group was fed a conventional diet (20 kg of dry matter/head per day), whereas the experimental group (EG) received the conventional diet supplemented with DOP as 10% of dry matter. During the trial, milk yield was recorded and the samples of milk, cheese, total mixed rations, and DOP were collected and analyzed to determine the chemical-nutritional composition and aromatic profile. Atherogenic and thrombogenic indices were calculated on the basis of the fatty acid (FA) profile of milk and cheese. Data were analyzed according to the mixed model for milk yield and chemical composition, including cows nested within treatment as a random effect, whereas the general linear model was used for the analysis of cheese parameters. Differences were assessed by Tukey's test. The EG diet had a lower content of palmitic, stearic, and linoleic acids and a higher level of oleic acid compared with the control. Dietary DOP integration did not affect milk yield and composition with the exception of protein content, which was greater in EG and significantly affected by diet and period. Instead, period was found to be significant for fat and casein in both groups. Dietary supplementation with DOP modified the FA profile of milk and cheese. There was a decrease in short- and medium-chain FA, but significance was achieved only for palmitic acid. The stearic, isomer trans of oleic (in particular vaccenic acid), oleic, and isomer trans of linoleic acids significantly increased. Monounsaturated FA increased in EG milk and cheese and saturated FA were significantly lower, whereas no difference was marked between the groups regarding level of polyunsaturated FA. Supplementation with DOP reduced atherogenic and thrombogenic indices and increased conjugated linoleic acid in both milk and cheese. The free fatty acids, ketones, lactones, esters, and phenylalanine catabolites were increased in raw milk, whereas only leucine metabolism was affected by diet in pasteurized milk cheese at both 1 and 30 d of ripening. The present results pointed out that DOP supplementation may improve the nutritional and nutraceutical properties and modify the aroma of milk and derived cheese.

Impact of dietary fat on gut microbiota and low-grade systemic inflammation: mechanisms and clinical implications on obesity

Dietary fat strongly affects human health by modulating gut microbiota composition and low-grade systemic inflammation. High-fat diets have been implicated in reduced gut microbiota richness, increased Firmicutes to Bacteroidetes ratio, and several changes at family, genus and species levels. Saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA) and conjugated linolenic fatty acids share important pathways of immune system activation/inhibition with gut microbes, modulating obesogenic and proinflammatory profiles. Mechanisms that link dietary fat, gut microbiota and obesity are mediated by increased intestinal permeability, systemic endotoxemia, and the activity of the endocannabinoid system. Although the probiotic therapy could be a complementary strategy to improve gut microbiota composition, it did not show permanent effects to treat fat-induced dysbiosis. Based upon evidence to date, we believe that high-fat diets and SFA consumption should be avoided, and MUFA and omega-3 PUFA intake should be encouraged in order to regulate gut microbiota and inflammation, promoting body weight/fat control.

Effect of Conjugated Linoleic Acid Intake on Endurance Exercise Performance and Anti-fatigue in Student Athletes

Conjugated linoleic acids (CLA) intake has been reported to reduce body fat mass or increase lean body mass and to improve exercise outcome by modulating testosterone in humans. These reports have studied mostly overweight subjects; few were athletes. Therefore, in this study, the effect of CLA intake on endurance performance and anti-fatigue in student athletes was investigated. A double-blind, crossover study was conducted with 10 male student athletes. Each subject was administered with either CLA (net 0.9 g/day) or a placebo for 14 days. They were subjected to an exercise tolerance test (steady loading) using a cycle ergometer on days 0 and 14. Peak VO₂ was determined for each subject using a graded loading test. The steady loading test was performed with a pedaling exercise load of 50% peak VO₂ for 40 min and then with a load of 70% peak VO₂ until exhaustion. Blood sampling and measurement of critical flicker frequency (CFF) were performed before and after exercise. The rate of perceived exertion (RPE) was measured serially during exercise. In the results, amount of body weight variation significantly increased and amount of body fat percentage variation tended to decrease by CLA intake, it might have an effect by increase in muscle mass. In addition, amount of exercise time variation significantly increased, amount of variation of CFF before and after exercise tended to increase, that of RPE during exercise tended to decrease, and that of creatine phosphokinase before and after exercise tended to decrease in the CLA group. These results suggested that CLA intake for 14 days might have an effect on endurance performance and anti-fatigue in student athletes.

Substitutions of dairy product intake and risk of stroke: a Danish cohort study

Low fat dairy products are part of dietary guidelines to prevent stroke. However, epidemiological evidence is inconclusive with regard to the association between dairy products and stroke. We therefore investigated associations for substitutions between dairy product subgroups and risk of total stroke and stroke subtypes. We included 55,211 Danish men and women aged 50-64 years without previous stroke. Baseline diet was assessed by a food frequency questionnaire. Cases were identified through a national register and subsequently verified. The associations were analyzed using Cox proportional hazard regression. During a median follow-up of 13.4 years, we identified 2272 strokes, of which 1870 were ischemic (318 large artery atherosclerotic, 839 lacunar, 102 cardioembolic, 98 other determined types, 513 of unknown type), 389 were hemorrhages (273 intracerebral, 116 subarachnoid) and 13 of unknown etiology. Substitution of semi-skimmed fermented milk or cheese for whole-fat fermented milk was associated with a higher rate of ischemic stroke [semi-skimmed fermented milk: hazard ratio (HR) = 1.20 (95% confidence interval (CI) 0.99-1.45), cheese: HR = 1.14 (95% CI 0.98-1.31) per serving/day substituted] and substitutions of whole-fat fermented milk for low-fat milk, whole-fat milk or buttermilk were associated with a lower rate [low-fat milk: HR = 0.85 (95% CI 0.74-0.99), whole-fat milk: HR = 0.84 (95% CI 0.71-0.98) and buttermilk: HR = 0.83 (95% CI 0.70-0.99)]. We observed no associations for substitutions between dairy products and hemorrhagic stroke. Our results suggest that intake of whole-fat fermented milk as a substitution for semi-skimmed fermented milk, cheese, buttermilk or milk, regardless of fat content, is associated with a lower rate of ischemic stroke.

Fatty Acids Have Different Adipogenic Differentiation Potentials in Stromal Vascular Cells Isolated from Abdominal Fat in Laying Hens

This study was conducted to examine the effects of fatty acids (FA) with/without chicken serum (CS) on the expression of adipogenic transcripts and adipogenesis in chicken stromal vascular cells (SVC). In experiment 1, SVC were grown in DMEM containing 10% FBS (Control) and treated with 300 µM oleic acid (OLA) + FBS, linoleic acid (LNA) + FBS, palmitic acid (PAM) + FBS, or stearic acid (STA) + FBS for 48 h. In experiment 2, cells were grown in DMEM containing 5% CS and treated with 300 µM OLA (CS + OLA), PAM (CS + PAM), STA (CS + STA) or 200 µM LNA (CS + LNA) for 48 h. Adipogenesis was determined using Oil Red O staining and glycerol-3-phosphate dehydrogenase (GPDH) activity. The proportion of OLA, PAM, or STA was increased (P < 0.05) in SVC grown in either FBS or CS with OLA, PAM or STA. Adipogenesis was induced in FBS + OLA, FBS + LNA, FBS + PAM, FBS + STA, CS + OLA, CS + LNA, CS + PAM, or CS + SAT compared to FBS. GPDH activity was significantly higher in FBS + OLA and FBS + LNA than one in FBS. Compared to FBS, the expression of FABP4 mRNA increased (P < 0.05) in FBS + OLA, FBS + LNA, or FBS + PAM, whereas that of C/EBPα, C/EBPβ, and ATGL increased (P < 0.05) in FBS + OLA or FBS + LNA cells. Expression of FABP4 and C/EBPβ mRNA was higher in CS, CS + OLA, CS + LNA, CS + PAM, or CS + SAT compared with (FBS, whereas the expression of ATGL and C/EBPα was higher in CS, CS + OLA, or CS + LNA than FBS cells. In conclusion, these results showed that FA have different potentials to induce adipogenesis, LNA is the most potent among the tested FA, and these potentials can be improved in the presence of CS.

Nutritional enhancement of sheep meat fatty acid profile for human health and wellbeing

Dietary fatty acids (FA) consumed by sheep, like other ruminants, can undergo biohydrogenation resulting in high proportions of saturated FA (SFA) in meat. Biohydrogenation is typically less extensive in sheep than cattle, and consequently, sheep meat can contain higher proportions of omega (n)-3 polyunsaturated FA (PUFA), and PUFA biohydrogenation intermediates (PUFA-BHI) including conjugated linoleic acid (CLA) and trans-monounsaturated FAs (t-MUFA). Sheep meat is also noted for having characteristically higher contents of branched chain FA (BCFA). From a human health and wellness perspective, some SFA and trans-MUFA have been found to negatively affect blood lipid profiles, and are associated with increased risk of cardiovascular disease (CVD). On the other hand, n-3 PUFA, BCFA and some PUFA-BHI may have many potential beneficial effects on human health and wellbeing. In particular, vaccenic acid (VA), rumenic acid (RA) and BCFA may have potential for protecting against cancer and inflammatory disorders among other human health benefits. Several innovative strategies have been evaluated for their potential to enrich sheep meat with FA which may have human health benefits. To this end, dietary manipulation has been found to be the most effective strategy of improving the FA profile of sheep meat. However, there is a missing link between the FA profile of sheep meat, human consumption patterns of sheep FA and chronic diseases. The current review provides an overview of the nutritional strategies used to enhance the FA profile of sheep meat for human consumption.

Strategies for Producing and Incorporating Conjugated Linoleic Acid–Rich Oils in Foods

Conjugated linoleic acid (CLA) is in ruminant-derived foods and is known to combat obesity-related diseases. However, CLA levels in a healthy diet are too low to produce a clinical effect. Therefore, CLA has been produced by linoleic isomerization through fermentation and chemical catalysis. Many of these techniques are not practical for food production, but a recent development has enabled production of CLA-rich triglyceride vegetable oils from high linoleic acid oils by a minor modification of conventional food-oil processing techniques. These oils were used to produce common lipid-based food, such as margarine, shortenings, and salad dressings, whose quality was enhanced by the presence of CLA-rich oil and provided a significant CLA source. Meat and egg CLA content and subsequent food quality can also be increased by addition of dietary CLA. However, consumer awareness of CLA benefits needs to increase prior to commercial-scale production of CLA-rich oil.

Evaluation of the Impact of Ruminant Trans Fatty Acids on Human Health: Important Aspects to Consider

The definition and evaluation of trans fatty acids (TFA) with regard to foodstuffs and health hazard are not consistent. Based on the current situation, the term should be restricted only to TFA with isolated double bonds in trans-configuration. Conjugated linoleic acids (CLA) should be separately assessed. Ideally, the origin of the consumed fat should be declared, i.e., ruminant TFA (R-TFA) and industrial TFA (non-ruminant; I-TFA). In ruminant fat, more than 50% of R-TFA consists of vaccenic acid (C18:1 t11). In addition, natural CLA, i.e., c9,t11 CLA is also present. Both are elevated in products from organic farming. In contrast to elaidic acid (t9) and t10, which occur mainly in partially hydrogenated industrial fat, t11 is partially metabolized into c9,t11 CLA via Δ9-desaturation. This is the major metabolic criterion used to differentiate between t11 and other trans C18:1. t11 indicates health beneficial effects in several studies. Moreover, CLA in milk fat is associated with the prevention of allergy and asthma. An analysis of the few studies relating to R-TFA alone makes clear that no convincing adverse physiological effect can be attributed to R-TFA. Only extremely high R-TFA intakes cause negative change in blood lipids. In conclusion, in most European countries, the intake of R-TFA is assessed as being low to moderate. Restriction of R-TFA would unjustifiably represent a disadvantage for organic farming of milk.

Differences in the skeletal muscle transcriptome profile associated with extreme values of fatty acids content

Background

Lipids are a class of molecules that play an important role in cellular structure and metabolism in all cell types. In the last few decades, it has been reported that long-chain fatty acids (FAs) are involved in several biological functions from transcriptional regulation to physiological processes. Several fatty acids have been both positively and negatively implicated in different biological processes in skeletal muscle and other tissues. To gain insight into biological processes associated with fatty acid content in skeletal muscle, the aim of the present study was to identify differentially expressed genes (DEGs) and functional pathways related to gene expression regulation associated with FA content in cattle.

Results

Skeletal muscle transcriptome analysis of 164 Nellore steers revealed no differentially expressed genes (DEGs, FDR 10%) for samples with extreme values for linoleic acid (LA) or stearic acid (SA), and only a few DEGs for eicosapentaenoic acid (EPA, 5 DEGs), docosahexaenoic acid (DHA, 4 DEGs) and palmitic acid (PA, 123 DEGs), while large numbers of DEGs were associated with oleic acid (OA, 1134 DEGs) and conjugated linoleic acid cis9 trans11 (CLA-c9t11, 872 DEGs). Functional annotation and functional enrichment from OA DEGs identified important genes, canonical pathways and upstream regulators such as SCD, PLIN5, UCP3, CPT1, CPT1B, oxidative phosphorylation mitochondrial dysfunction, PPARGC1A, and FOXO1. Two important genes associated with lipid metabolism, gene expression and cancer were identified as DEGs between animals with high and low CLA-c9t11, specifically, epidermal growth factor receptor (EGFR) and RNPS.

Conclusion

Only two out of seven classes of molecules of FA studied were associated with large changes in the expression profile of skeletal muscle. OA and CLA-c9t11 content had significant effects on the expression level of genes related to important biological processes associated with oxidative phosphorylation, and cell growth, survival, and migration. These results contribute to our understanding of how some FAs modulate metabolism and may have protective health function.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-3306-x) contains supplementary material, which is available to authorized users.

Distinct fatty acid composition of some edible by-products from bovines fed high or low silage diets

In the present study, it was hypothesized that the incorporation of fatty acids is distinct among ruminant tissues and that it could be modulated by diet composition. To test this hypothesis, fatty acid composition, including conjugated linoleic acid isomers, of the most relevant beef by-products (brain, heart, kidney, liver, pancreas and tongue) from young bulls those fed distinct silage levels was assessed. Data indicated a large variation in fatty acid profile and conjugated linoleic acid composition among edible by-products. The most abundant fatty acids were C16:0 (kidney), C18:0 (heart and liver) and C18:1 c9 (brain, pancreas and tongue) followed by C20:4 n-6, except in brain (C22:6 n-3 predominates). Brain, as shown by principal component analysis, presents a distinct fatty acid composition compared to the other beef by-products analysed. In addition, high silage diet relative to low silage diet promoted an increase of n-3 polyunsaturated fatty acid, t11, t13 and t11, c13 conjugated linoleic acid in heart, kidney, liver and pancreas. Overall, the data suggested that beef by-products had, in general, high contents of cholesterol, saturated fatty acid and trans fatty acid, as well as high levels of conjugated linoleic acid. Therefore, from a nutritional point of view they are recommended only in small amounts as part of a balanced diet.

Effects of Conjugated Linoleic Acid Associated With Endurance Exercise on Muscle Fibres and Peroxisome Proliferator-Activated Receptor γ Coactivator 1 α Isoforms

Conjugated linoleic acid (CLA) has been reported to improve muscle hypertrophy, steroidogenesis, physical activity, and endurance capacity in mice, although the molecular mechanisms of its actions are not completely understood. The aim of the present study was to identify whether CLA alters the expression of any of the peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) isoforms, and to evaluate the possible existence of fibre-type-specific hypertrophy in the gastrocnemius and plantaris muscles. Mice were randomly assigned to one of four groups: placebo sedentary, CLA sedentary, placebo trained, or CLA trained. The CLA groups were gavaged with 35 μl per day of Tonalin® FFA 80 food supplement containing CLA throughout the 6-week experimental period, whereas the placebo groups were gavaged with 35 μl sunflower oil each day. Each administered dose of CLA corresponded to approximately 0.7 g/kg or 0.5%, of the dietary daily intake. Trained groups ran 5 days per week on a Rota-Rod for 6 weeks at increasing speeds and durations. Mice were sacrificed by cervical dislocation and hind limb posterior muscle groups were dissected and used for histological and molecular analyses. Endurance training stimulated mitochondrial biogenesis by PGC1α isoforms (tot, α1, α2, and α3) but CLA supplementation did not stimulate PGC1α isoforms or mitochondrial biogenesis in trained or sedentary mice. In the plantaris muscle, CLA supplementation induced a fibre-type-specific hypertrophy of type IIx muscle fibres, which was associated with increased capillary density and was different from the fibre-type-specific hypertrophy induced by endurance exercise (of types I and IIb muscle fibres). J. Cell. Physiol. 232: 1086-1094, 2017. © 2016 Wiley Periodicals, Inc.

Conjugated linoleic acid (CLA) promotes endurance capacity via peroxisome proliferator-activated receptor δ-mediated mechanism in mice

Previously, it was reported that conjugated linoleic acid (CLA) with exercise training potentially improved endurance capacity via the peroxisome proliferator-activated receptor δ (PPARδ)-mediated mechanism in mice. This study determined the role of exercise and/or CLA in endurance capacity and PPARδ-associated regulators. Male 129Sv/J mice were fed either control (soybean oil) or CLA (0.5%) containing diets for 4 weeks and were further divided into sedentary or training regimes. CLA supplementation significantly reduced body weight and fat mass independent of exercise during the experimental period. Endurance capacity was significantly improved by CLA supplementation, while no effect of exercise was observed. Similarly, CLA treatment significantly increased expressions of sirtuin 1 and PPARγ coactivator-1α, up-stream regulators of PPARδ, in both sedentary and trained animals. With respect to downstream markers of PPARδ, CLA up-regulated the key biomarker needed to stimulate mitochondrial biogenesis, nuclear respiratory factor 1. Moreover, CLA supplementation significantly induced overall genes associated with muscle fibers, such as type I (slow-twitch) and type II (fast twitch). Taken together, it suggests that CLA improves endurance capacity independent of mild-intensity exercise via PPARδ-mediated mechanism.

Dietary conjugated linoleic acid affects blood parameters, liver morphology and expression of selected hepatic genes in laying hens

The objective of this research were to investigate the effect of a conjugated linoleic acid (CLA)-enriched diet on Isa Brown laying hen health status and to provide a comprehensive analysis of changes in blood parameters, liver morphology and selected hepatic gene expression. Hens were allocated to the control and experimental group (diet enriched with 0.75% CLA) for a total period of 4 m. At the end of the experiment half of the hens from each group were slaughtered for analyses. The remaining hens were transferred to an organic farm for the next 5 m and fed on the diet without CLA supplementation. The CLA-enriched diet resulted in significant changes in blood and serum parameters; specifically, haematocrit (HCT), mean corpuscular volume (MCV) and white blood cells (WBC) count were decreased compared to the control. The total cholesterol (TC) was not significantly affected while the triacylglycerol's (TG) concentration was elevated. The activity of alanine aminotransferase (ALT) was significantly increased in the CLA-supplemented group, while aspartate aminotransferase (AST) showed an increasing tendency. Liver biopsies showed pathological changes classified as non-alcoholic fatty liver disease (NAFLD). Additionally, the expression of hepatic genes involved in fatty acids synthesis (ME1, ACLY, ACC, FASN, SCD1), oxidation (CPT1α, PPARA), detoxification processes (Cytochrome P450, CYP, Flavin-containing monooxygenase, FMO3), oxidative stress (NOX4, XbP1) and inflammation (IL6, TNFα) were elevated. Cessation of CLA supplementation for 5 m of organic farming resulted in normalisation of blood and hepatic parameters to the levels observed in control hens. The results of this study indicate that dietary CLA triggers an integrated stress response in laying hens and activates mechanisms involved in liver detoxification.