Incorporation Of Conjugated Linoleic Acid Research Articles

The enzymatic modification of phospholipids improves their surface-active properties and the formation of nanoemulsions

Phosphatidylcholine (PC) is an appealing molecule for stabilizing nanoemulsions due to its natural origin. PC can be modified to improve its physicochemical features or biological activities. On the other hand, conjugated linoleic acid (CLA) is a fatty acid with proven favorable biological activities. Replacing native PC fatty acids with CLA could modify the physicochemical properties of PC as well as its biological benefits. PC was enzymatically modified in this work to replace some of its fatty acids with CLA. The results showed molar incorporation of CLA of 56.3%, with reaction yields of 71.5%. In addition, we found that the modified PC enabled the reduction of its critical micelle concentration from 1.05 mM to 0.083 mM. Finally, both phospholipids successfully formed nanoemulsions with particle sizes of ca. 57 nm; however, nanoemulsions developed with modified PC showed greater stability after 60 days, demonstrating a superior surface coverage of the modified PC to the nanoemulsion.

Supplementing conjugated linoleic acid in breeder hens diet increased conjugated linoleic acid incorporation in liver and alters hepatic lipid metabolism in chick offspring.

This experiment was designed to investigate the effect of supplementing conjugated linoleic acid (CLA) in breeder hens diet on development and hepatic lipid metabolism of chick offspring. Hy-Line Brown breeder hens were allocated into two groups, supplemented with 0 (control (CT)) or 0·5 % CLA for 8 weeks. Offspring chicks were grouped according to the mother generation and fed for 7 d. CLA treatment had no significant influence on development, egg quality and fertility of breeder hens but darkened the egg yolks in shade and increased yolk sac mass compared with the CT group. Addition of CLA resulted in increased body mass and liver mass and decreased deposition of subcutaneous adipose tissue in chick offspring. The serum TAG and total cholesterol levels of chick offspring were decreased in CLA group. CLA treatment increased the incorporation of both CLA isomers (c9t11 and t10c12) in the liver of chick offspring, accompanied by the decreased hepatic TAG levels, related to the significant reduction of fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) enzyme activities and the increased carnitine palmitoyltransferase-1 (CPT1) enzyme activity. Meanwhile, CLA treatment reduced the mRNA expression of genes related to fatty acid biosynthesis (FAS, ACC and sterol regulatory element-binding protein-1c) and induced the expression of genes related to β-oxidative (CPT1, AMP-activated protein kinase and PPARα) in chick offspring liver. In summary, the addition of CLA in breeder hens diet significantly increased the incorporation of CLA in the liver of chick offspring, which further regulate hepatic lipid metabolism.

Production of structured lipids from hazelnut oil with conjugated linoleic acid by lipase-catalyzed esterification: Optimization by response surface methodology

The aim of this study was to synthesize structured lipid from hazelnut oil with conjugated linoleic acid (CLA) by lipase-catalyzed esterification reaction. The incorporation of CLA into hazelnut oil was optimized by response surface methodology (RSM). Substrate molar ratio, time, and temperature were independent variables chosen for optimization of the reaction. Substrate molar ratio was the most significant variable on the incorporation of conjugated linoleic acid. Good quadratic model was achieved by multiple regression analysis and backward elimination. Optimal incorporation conditions were determined as follows: reaction temperature, 59 °C; time, 6 hours; substrate molar ratio, 4. Under these optimum conditions, a maximum incorporation ratio of CLA into hazelnut oil of 49.42% was achieved.

Lipid Composition and Antioxidant Capacity Evaluation in Tilapia Fillets Supplemented with a Blend of Oils and Vitamin E

AbstractSince the nutritional value of farm‐raised fish fillets is directly related to the diet provided, we supplemented the diet of Tilapia (Oreochromis niloticus) with a blend of chia (Salvia hispanicaL.) oil, tung (Aleurites fordii) oil, and conjugated linoleic acid (CLA) to evaluate the effects on the fatty acid composition. Vitamin E was also added to the diet to improve the antioxidant capacity of tilapia fillets. We observed an increase in α‐linolenic acid content (from 6.56 to 19.03 mg g−1of total lipids), as well as the incorporation of CLA and conjugated linolenic acid (CLnA) isomers in the fillets. The addition of vitamin E resulted in the antioxidant capacity improvement of the fillets and higher values were found after 15 feeding days (39.25 µmol TE g−1in the Ferric Reducing Ability Power assay). Supplementation proved to be an excellent tool to improve the nutritional value of fish fillets.

Lipase Catalyzed Incorporation of Conjugated Linoleic Acid by Transesterification into Sunflower Oil Applying Immobilized Lipase (Lipozyme Thermomyces lanuginosus and Rhizomucor mehei)

Conjugated Linoleic Acid (CLA), Glycerol (G) and sunflower oil blends with varying concentration were subjected to enzymatic esterification using a 1, 3- specific immobilized lipase. CLA was used as acyl due to its purported health benefits. The transesterified lipids were evaluated for free fatty acids (FFA) and composition of fatty acids by gas chromatography. Lipozyme RM IM is preferred for enzymatic esterification because of more CLA incorporation and less free fatty acids at the end of reaction than Lipozyme TL IM. Response surface methodology (RSM) was used to determine the effects of three variables Glycerol concentration, reaction temperature, and amount of enzyme on the lipase catalyzed incorporation of CLA into Sunflower oil. The optimum condition for maximum CLA incorporation (96.7% Incorporation Yield), maximum reaction rate (0.0271 M/h) and minimum free fatty acids production (Acid No.2.73) was obtained, at 75 C by using 3 % enzyme and 0.27 M glycerol.

Production of concentrates of CLA obtained from sunflower and safflower and their application to the lipase‐catalyzed acidolysis of egg yolk phosphatidylcholine

The process of acidolysis of egg yolk phosphatidylcholine (PC) with concentrates of conjugated linoleic acid (CLA) was performed. CLA was obtained by the alkali isomerization of sunflower and safflower oils. Analysis of the influence of different reaction conditions on the process of isomerization was investigated. Reactions were carried out in preparative scale at 150°C in the ethylene glycol and afforded the mixture of isomers: cis‐9,trans‐11 and trans‐10,cis‐12. Their content was 30.8 and 32.3% for product obtained from sunflower oil and 30.4 and 36.4% for the product obtained from safflower oil. Crude concentrates were purified by urea complexation with 1:3 fatty acids to urea weight ratio. Enzymatic modification of phosphatidylcholine from egg yolk with CLA concentrates was carried out using lipase from Rhizomucor miehei. The process was performed at 45°C with controlled water activity. The highest effective incorporation (42%) of CLA into PC and lysophosphatidylcholine molecules was obtained using concentrate from the sunflower and safflower oils after 36 h of reaction.Practical applications: Results of this research are useful for the development of scaled up acidolysis reaction to produce phosphatidylcholine enriched in biologically active isomers of CLA using the sunflower or safflower oil as a rich source of linolenic acid.Application of the concentrates of CLA obtained from sunflower and safflower oils to the enzymatic acidolysis of egg yolk phosphatidylcholine.

Dietary CLA supplementation of pigs confers higher oxidative stability to Ciauscolo and Fabriano salami produced from their meat with no negative impact on the physico‐chemical, microbiological and sensorial characteristics

It has been reported that conjugated linoleic acid (CLA) isomers are considered particularly beneficial to human health and affect the technological properties of pork meat products such as salami. The objective of this study was to evaluate the effect of 0.5% CLA supplementation of heavy pig diets on the chemical composition, total fatty acids (FA), oxidative stability, sensory and microbial properties of Ciauscolo and Fabriano salami. The incorporation of CLA into the diet did not modify the chemical, microbial or sensory descriptive analysis of the salami. The CLA dietary supplementation changed the proportions of FA, in particular leading to an increase in the proportion of saturated fatty acids and CLA in both Ciauscolo and Fabriano salami. The results of consumer testing showed a higher degree of liking by consumers when the CLA sample was accompanied by product information, demonstrating the strong influence of the label on consumer perception. The interesting finding was the increase in the oxidative stability of the salami at the end of ripening. This confirms the hypothesis that CLA can affect the saturated and monounsaturated fatty acids/monounsaturated FA ratio in meat products and possesses antioxidative properties that can be transferred, through dietary supplementation, to salami.Practical applications: Feeding a 0.5% CLA diet to finisher pigs resulted in changes in the proportions of FA and enhanced the oxidative stability of salami but did not modify the sensory properties of the products. More research is needed to find the right inclusion level of CLA to be considered optimal from the point of view of producing a high quality product with superior organoleptical, technological and potential health‐related properties.Production of value‐added meat products, such as conjugated linoleic acids (CLA) enriched Ciauscolo and Fabriano salamis, by the inclusion of the c9 t11 and t10 c12 CLA isomers in the swine diet.

Lipase-catalyzed enrichment of egg yolk phosphatidylcholine with conjugated linoleic acid

The investigations were carried out to elaborate an efficient process of lipase-catalyzed acidolysis of egg yolk phosphatidylcholine (PC) with conjugated linoleic acid (CLA) taking into account both a high degree of incorporation into phospholipids (PLs) as well as the high yields of modified PLs. Therefore a term of “effective incorporation of CLA” (ECLA) was proposed as the most complex criterion for the evaluation of effectiveness of the process. The best results were achieved when Lipozyme RM IM was applied and the reaction conditions were as follows: CLA/PC molar ratio 8:1; enzyme loading 24% wt. based on substrates; reaction medium heptane; temperature 45°C; time 36h. Reaction was conducted under initial aw=0.33 which was changed after 12h to aw=0.11. Under these conditions incorporation of CLA (calculated as % of total FA) into modified PC and lysophosphatidylcholine (LPC) reached 33.8% and 50.1%, respectively. The ECLA incorporation reached 39.0%. The yields of PC and LPC were 39.5% and 25.3%, respectively. The results showed the highest effective incorporation of CLA into PC in comparison to the data reported previously.

Effect of conjugated linoleic acid in diacylglycerol-rich oil on the lipid metabolism of C57BL/6J mice fed a high-fat high-cholesterol diet

The effect of conjugated linoleic acid (CLA) isomers esterified in diacylglycerol (DAG)-rich oil on lipid metabolism was investigated. Since dietary DAG has been known to induce the regression of atherosclerosis, CLA-DAG and olive-DAG oils containing similar levels of DAG (51.4~54.2%) were synthesized from olive oil. Hyperlipidemic C57BL/6J mice were then fed high-fat high-cholesterol diets supplemented with these oils (5% each) for 7 wk. The CLA-DAG diet containing 2.1% CLA isomers (0.78% c9,t11-CLA; 1.18% t10,c12-CLA) remarkably increased the levels of total plasma cholesterol and glutamic oxaloacetic transaminase (GOT) along with hepatic cholesterol and triacylglycerol (TAG) contents. Furthermore, the CLA-DAG diet inhibited fat uptake into adipose tissue whereas fat deposition (especially in the liver) was increased, resulting in the development of fatty livers. Hepatic fatty acid composition in the CLA-DAG mice was different from that of the olive-DAG mice, showing higher ratios of C16:1/C16:0 and C18:1/C18:0 in the liver. The activity of hepatic acyl-CoA:cholesterol acyltransferase (ACAT) was higher in CLA-DAG mice while plasma lecithin:cholesterol acyltransferase (LCAT) activity and the ferric reducing ability of plasma (FRAP) were lower in CLA-DAG mice compared to the olive-DAG animals. Results of the present study suggest that CLA incorporation into DAG oil could induce atherosclerosis in mice.

Incorporation of conjugated linoleic and alpha linolenic fatty acids into Pimedolus maculatus fillets

The objective of this study was to investigate the fatty acid composition of Pimedolus maculatus fillets of fish fed with different diets. The fish were submitted to an adaptation period (over 30 days) and fed only a control diet (diet I). After this period, the fish were divided into two groups: one group received a diet enriched with flaxseed oil (diet II), and the other received a diet enriched with conjugated linoleic acid (CLA) (diet III). Subsequent collections were undertaken after 25 and 50 days. Compared to the control samples, fish fed diet II showed an increase in concentrations of total fatty acid omega-3 (n-3) in the fillets, with an improvement ratio of n-6/n-3. The incorporation of CLA into fish fed diet III was successful. Supplementing the diet of Pimedolus maculatus with CLA and flaxseed oil led to improvements in nutritional quality and fatty acid profile of the fish fillets.

Incorporation of conjugated linoleic acid into brain lipids is not necessary for conjugated linoleic acid–induced reductions in feed intake or body fat in mice

Dietary conjugated linoleic acid (CLA) causes reduced feed intake (FI) and body fat (BF). It is unknown, though, if CLA incorporation into tissues, alterations in serum hormones, and/or appetite-regulating neuropeptides are involved. We hypothesized that CLA incorporation into brain lipids would be correlated with changes in appetite-regulating neuropeptide expression and reductions in FI and BF. Male mice (n = 150; 9 weeks old, ICR) received the control diet ad libitum (CON), 2% CLA diet ad libitum (CLA), or control diet pair-fed to the intake of CLA-fed mice for 1, 2, 3, 5, or 7 days. Both FI and body weight were measured daily, and a BF index was calculated. Liver, adipose, and brain fatty acids; serum insulin, leptin, and peptide YY; and arcuate nucleus neuropeptide Y, agouti-related protein, and α-melanocyte–stimulating hormone protein were determined. Mice fed CLA ate less (P < .05) than did the CON on days 1, 2, 3, and 7 but were leaner (P < .05) only on day 7. Mice that received the control diet pair-fed to the intake of CLA-fed mice did not differ in BF from the CON. By days 1 and 2, CLA isomers were incorporated into the liver and adipose but not in the brain. Insulin was increased in CLA-fed mice on days 5 and 7, and leptin was decreased on day 7. Peptide YY and the neuropeptides did not differ. Tissue CLA was not correlated with FI, body weight, or BF but was positively correlated with insulin and negatively correlated with leptin. The reduction in FI is not sufficient to cause the reduction in BF, and tissue CLA accumulation does not appear to be required.

Use of immobilized phospholipase A1-catalyzed acidolysis for the production of structured phosphatidylcholine with an elevated conjugated linoleic acid content

Structured phosphatidylcholine (SPC) was successfully produced via immobilized phospholipase A 1 (PLA 1 ) – catalyzed acidolysis of phosphatidylcholine (PC) with conjugated linoleic acid (CLA). The effects of enzyme loading (2, 5, 10, 15 and 20%, with respect to the weight of substrates), temperature (20, 30, 40, 50 and 60 °C) and the molar ratio of substrates (1:2, 1:4, 1:6, 1:8 and 1:10, PC/CLA) were evaluated to maximize the incorporation of CLA into PC. The maximum incorporation of CLA achieved was ca. 90% for 24 h of reaction at 50 °C and 200 rpm, using a 1:4 substrate molar ratio and an enzyme loading of 15%.

A mixture of oleic, erucic and conjugated linoleic acids modulates cerebrospinal fluid inflammatory markers and improve somatosensorial evoked potential in X‐linked adrenoleukodystrophy female carriers

X−linked adrenoleukodystrophy is a rare inherited demyelinating disorder characterized by an abnormal accumulation of very long chain fatty acids, mainly hexacosanoic acid (26:0), due to a mutation of the gene encoding for a peroxisomal membrane protein. The only available, and partially effective, therapeutic treatment consists of dietary intake of a 4:1 mixture of triolein and trierucin, called Lorenzo’s oil (LO), targeted to inhibit the elongation of docosanoic acid (22:0) to 26:0. In this study we tested whether, besides inhibiting elongation, an enhancement of peroxisomal beta oxidation induced by conjugated linoleic acid (CLA), will improve somatosensory evoked potentials and modify inflammatory markers in adrenoleukodystrophy females carriers. We enrolled five heterozygous women. They received a mixture of LO (40 g/day) with CLA (5 g/day) for 2 months. The therapeutic efficacy was evaluated by the means of plasma levels of 26:0, 26:0/22:0 ratio, modification of cerebrospinal fluid (CSF) inflammatory markers and somatosensory evoked potentials. Changes of fatty acid profile, and in particular CLA incorporation, were also evaluated in CSF and plasma. The results showed that CLA promptly passes the blood brain barrier and the mixture was able to lower both 26:0 and 26:0/22:0 ratio in plasma. The mixture improved somatosensory evoked potentials, which were previously found unchanged or worsened with dietary LO alone, and reduced IL-6 levels in CSF in three out of five patients. Our data suggest that the synergic activity of CLA and LO, by enhancing peroxisomal beta-oxidation and preventing 26:0 formation, improves the somatosensory evoked potentials and reduces neuroinflammation.

Effects of dietary replacement of fish oil by conjugated linoleic acid on some meat quality traits of Pacific white shrimp Litopenaeus vannamei

This experiment was conducted to evaluate the effects of fish oil replacement by conjugated linoleic acid (CLA) on body proximate analysis and thiobarbituric acid-reactive substances, fat content, shear force and fatty acid composition in musculature of Pacific white shrimp ( Litopenaeus vannamei). Graded levels of CLA (0%, 0.5%, 1% and 2%) were added to the basic diet of shrimp at the expense of fish oil. Results showed that fat content ( p = 0.036) and shear force ( p = 0.001) in shrimp musculature were enhanced with increasing dietary CLA inclusion. Fish oil replacement by CLA significantly promoted the incorporation of cis-9, trans-11 CLA ( p = 0.0001) and trans-10, cis-12 CLA ( p < 0.0001) into shrimp musculature; moreover, the polyunsaturated fatty acid was elevated ( p = 0.020) and monounsaturated fatty acid was reduced by CLA inclusion ( p = 0.024). It was concluded that replacement of fish oil by CLA could improve some meat quality traits of shrimp and 1% CLA was an appropriate amount.

Evaluation of Conjugated Linoleic Acid Addition to a Chocolate Milk Drink

Aiming the development of a chocolate milk drink added of conjugated linoleic acid (CLA), some parameters, such as equipment type (blender and ultraturrax) and stirring time (1, 2 and 5 min) were tested. Chocolate milk drinks normally found in Brazilian market served as basis for obtaining the preparation in this study. The results showed that CLA incorporation to the dairy drink was more efficient using the blender (11,500 rpm, 3 min) than ultraturrax (11,000 rpm, 5 min), since it produced a higher emulsion stability, which was evaluated by visual inspection and optical microscopy (OM). The size of the oil droplets ranged from 2.28 mm to 11.80 mm and was evaluated only by MO due to the impossibility of using dynamic light scattering associated to the polydispersion of all samples which was higher than 1.0. After hand-shaking the samples, the oil phase was reincorporated to the dispersed phase, indicating that no complete destabilization of the emulsion occurred.

Conjugated linoleic acid content in cecotrophes, suprarenal and intramuscular fat in rabbit fed commercial diets

An experiment was conducted to measure recycling through cecotrophes and retention of conjugated linoleic acid (CLA) in the body fat of rabbits. A commercial diet was formulated and given ad libitum to six New Zealand × Californian rabbits. Animals were weaned at 25 days of age and were reared in individual cages for five weeks, reaching an average body weight of 2.5 kg. Excretion of soft faeces was individually determined for 24 h after putting a wooden collar around the animals' neck. Ether extract content and fatty acid profile were determined in both soft and hard faeces, and also in the suprarenal and intramuscular fat. CLA cis-9, trans-11 isomer was detected in faeces and tissues. The CLA concentration was higher in soft than in the hard faeces (6.4 vs. 3.6 g/kg total fatty acids). No difference in CLA concentration was found between tissues (muscle vs. adipose). However, CLA incorporation in muscle was only detected in the neutral lipid fraction. It was concluded that the amount of CLA cis-9, trans-11 isomer recycled through cecotrophy in rabbits fed a commercial diet is retained in similar proportions in the suprarenal and intramuscular fat, but differs in the lipid classes.

Incorporation of conjugated linoleic acid into mouse tissues and the regulation of feed intake and body fat in the short term

Conjugated linoleic acid (CLA) is known to decrease feed intake and body fat in mice. Our objectives were to determine the incorporation of CLA into tissues and the effect on serum hormones during the first 7 d of CLA consumption. Mice (n=150; 9‐wk‐old) were fed 0 (ad libitum or pair‐fed to CLA‐fed mice) or 2% CLA (ad libitum) for 1, 2, 3, 5, or 7 d. A body fat index was calculated; liver, adipose tissue, and brain were analyzed for fatty acid profiles; and serum insulin, leptin, and PYY were measured. CLA and pair‐fed mice ate less (P &lt; 0.05) than control mice on d 1, 2, 3, and 7, but CLA‐fed mice were leaner than control and pair‐fed mice only on d 7 (P &lt; 0.01). CLA was detected in adipose tissue starting on d 2 and in liver on d 1, but CLA was not detectable in the brain. Serum insulin tended (P = 0.11 and 0.13, respectively) to be increased in CLA‐fed mice on d 5 and 7, and serum leptin was non‐significantly reduced in CLA‐fed mice compared to control mice on d 7. The CLA‐induced reduction in feed intake was not sufficient to cause the loss of body fat as pair‐fed mice were not leaner than controls. The lack of CLA in the brain indicates that the effect on feed intake may be indirect.

Study of Some Experimental Parameters in the Synthesis of Triacylglycerols with CLA Isomers and Structural Analysis

AbstractThe present research deals with the synthesis of structured triacylglycerols (TAG) by enzymatic treatment of sn‐1,3‐diacylglycerol (sn‐1,3‐DAG) with conjugated linoleic acid (CLA) isomers using the immobilized lipase from Rhizomucor miehei (Lipozyme® IM) under different experimental conditions. In particular, the influence of reaction parameters, such as temperature, enzymatic load, reaction time and DAG/CLA ratio has been evaluated using an experimental design software with a screening objective. Two responses have been selected, they are the percentage of CLA isomers in total TAG and in the sn‐2‐ position and a three‐level‐4‐factor fractional factorial experimental design was used to screen the variables. The results showed that the selected experimental variables have an influence on the enzymatic reaction, in particular, the DAG/CLA substrate ratio and the temperature, both of which inversely correlated with CLA incorporation, but also the enzymatic load and the reaction time, both directly correlated with CLA incorporation. The best results for CLA isomer % content both in total TAG (46.3%) and in the sn‐2‐ position (52.2%) were obtained at 40 °C for 96 h, with 20% enzymatic load and a 0.5 reactive ratio.

Enzymatic Synthesis of Structured Triacylglycerols Containing CLA Isomers Starting from sn‐1,3‐Diacylglycerols

AbstractThe synthesis of structured triacylglycerols (TAG) by the enzymatic reaction between sn‐1,3‐diacylglycerols (sn‐1,3‐DAG) and conjugated linoleic acid (CLA) isomers was studied. Both the substrates of the reaction were produced from vegetable oils, the sn‐1,3‐DAG from extra virgin olive oil and the CLA isomers from sunflower oil. The enzymatic reactions between these substrates were catalyzed for 96 h by an immobilized lipase from Rhizomucor miehei (Lipozyme IM) and the reactions carried out in solvent were monitored every 24 h by using high‐performance liquid chromatography‐evaporative light scattering detector (HPLC‐ELSD). The enzymatic reactions were carried out in different reaction media (hexane, isooctane and solvent free) and with different CLA/sn‐1,3‐DAG ratios. Total % acidic composition and structural analysis data were evaluated to verify the presence of CLA isomers in sn‐2‐ position of synthesized TAG. The results showed good levels of CLA incorporation in sn‐1,3‐DAG, from 19.2% of TAG synthesized in solvent free conditions with a 0.5:1 substrate ratio, to 47.5% of TAG synthesized in isooctane with a 2:1 substrate ratio. It was observed that for all the reaction media, the best sn‐2‐ acylic specificity was obtained with a 0.5:1 substrate ratio.

Trans-11 Vaccenic Acid Dietary Supplementation Induces Hypolipidemic Effects in JCR:LA-cp Rats

Trans-11 vaccenic acid [VA; 18:1(n-9)] is a positional and geometric isomer of oleic acid and is the precursor to conjugated linoleic acid (CLA) in humans. Despite VA being the predominant trans monoene in ruminant-derived lipids, very little is known about its nutritional bioactivity, particularly in conditions of chronic metabolic disorders, including obesity, insulin resistance, and/or dyslipidemia. The aim of this study was to assess the potential of VA to improve dyslipidemia, insulin sensitivity, or inflammatory status in obese and insulin-resistant JCR:LA-cp rats. The obese rats and age-matched lean littermates were fed a control diet or a control diet supplemented with 1.5% (wt:wt) VA for a period of 3 wk. The incorporation of VA and subsequent conversion to CLA in triglyceride was measured in adipose tissue. Glucose and insulin metabolism were assessed via a conscious adapted meal tolerance test procedure. Plasma lipids as well as serum inflammatory cytokine concentrations were measured by commercially available assays. VA supplementation did not result in any observable adverse health effects in either lean or obese JCR:LA-cp rats. After 3 wk of feeding, body weight, food intake, and glucose/insulin metabolism did not differ between VA-supplemented and control groups. The incorporation of VA and CLA into adipose triglycerides in obese rats fed VA increased by 1.5-fold and 6.5-fold, respectively, compared with obese rats fed the control diet. The most striking effect was a 40% decrease (P < 0.05) in fasting triglyceride concentrations in VA-treated obese rats relative to obese controls. Serum Il-10 concentration was decreased by VA, regardless of genotype (P < 0.05). In conclusion, short-term dietary supplementation of 1.5% VA did not result in any detrimental metabolic effects in JCR:LA-cp rats. In contrast, dietary VA had substantial hypo-triglyceridemic effects, suggesting a new bioactivity of this fatty acid that is typically found in ruminant-derived food products.