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Conjugated linoleic acid isomers may affect the onset and severity of several diseases, including tumors, atherogenesis, and obesity. They may also modulate the immune response. However, little information regarding the most advantageous duration of CLA supplementation is available. The purpose of this study was to determine whether the length of dietary CLA supplementation of a sow affects growth, immune components, and metabolic and hormonal factors in lactating sows and piglets. Gestating sows were fed a control (0%) and a 0.5% CLA-supplemented diet beginning 7 d before parturition and ending 7 d postpartum (T1), or until weaning (T2; 7 sows per treatment). Colostrum and sow and piglet blood samples were collected for the determination of serum metabolite concentrations and immunoglobulin titer. Piglet BW at weaning were greater (P < 0.05) in the CLA groups compared with the control. Dietary CLA supplementation increased (P < 0.05) serum thyroxine concentration in sows, but serum insulin, glucose, NEFA, IGF-I, and leptin concentrations were not affected by CLA supplementation. Colostral IgG, IgA, and IgM titers were greater in sows fed CLA than in control sows (P < 0.05). At weaning (21 d), serum IgG titer of the piglets was greater (P < 0.05) in the T1 and T2 groups than the control group, but at 13 d postweaning, a difference (P < 0.05) was observed between the control and T2 group. The results from this study indicate potential beneficial effects of 0.5% dietary CLA supplementation from 7 d before parturition until 7 d postpartum in improving BW at weaning and immune components in piglets. Key words: conjugated linoleic acid, immunoglobulin, piglet, sow

The objective of this experiment was to determine the effects of dietary lipid source with or without the addition of CLA on bacon composition and quality. Forty-eight barrows at a beginning BW of 55 kg [+ or -] 2.2 were fed 1 of 6 diets for 56 d. These diets consisted of: 1) normal corn (NC), 2) NC + 1.25% CLA-60 oil (NC + CLA), 3) high-oil corn (HOC), 4) HOC + 1.25% CLA-60 oil (HOC-CLA), 5) NC + choice white grease (CWG; NC + CWG), and 6) NC + CWG + 1.25% CLA-60 oil (NC + CWG + CLA). The CLA-60 contains 60% CLA isomers in the oil, and therefore, 1.25% oil was needed to achieve 0.75% CLA in the diet. Soy oil replaced CLA in control diets. Choice white grease and high-oil corn were selected as fat sources for this study because of their utility in energy density for growing-finishing pigs, especially in hot weather. Pigs were slaughtered at an average BW of 113 kg [+ or -] 4.1, and carcasses were fabricated at 24 h postmortem. Statistical analysis was performed using the mixed model procedure of SAS, and the main effects tested were dietary lipid source, CLA, and 2-way interaction. The addition of CLA to each basal diet improved (P < 0.05) belly firmness measured either lean side down or fat side down from the belly bar firmness test [4.39 cm vs. 7.01 cm (lean down) and 5.75 cm vs. 10.54 cm (fat down)] for 0 and 0.75% dietary CLA, respectively. The compression test used on bacon slabs showed that bacon from CLA-supplemented pigs was approximately 20% firmer than that from controls. Pigs fed the HOC diets had softer bellies compared (P < 0.05) with pigs fed the NC diet as measured by the belly bar test [6.94 cm vs. 9.26 cm (fat down)], respectively. Conjugated linoleic acid did not, however, improve bacon sliceability. No differences were observed for moisture, protein, or lipid percentages between any treatments. Overall, there was a CLA effect (P < 0.04) for lipid oxidation, in which the addition of CLA decreased bacon oxidation (0.1498 CLA vs. 0.1638 no CLA). Dietary CLA increased the percentage of SFA in tissues from pigs supplemented with CLA. Dietary inclusion of CLA increased the concentration of all measured isomers of CLA in bacon. Sensory scores of bacon showed no differences for any of the sensory attributes measured between any of the treatments. Our results indicate that inclusion of dietary CLA will improve belly firmness, extend the shelf life stability of bacon, and increase the degree of fat saturation. Key words: bacon, belly, conjugated linoleic acid, pork

Dried corn distillers grains with solubles (DDGS) fed to swine may adversely affect carcass quality due to the high concentration of unsaturated fat. Feeding CLA enhances pork quality when unsaturated fat is contained in the diet. The effects of CLA on growth and pork quality were evaluated in pigs fed DDGS. Diets containing 0, 20, or 40% DDGS were fed to pigs beginning 30 d before slaughter. At 10 d before slaughter, one-half of each DDGS treatment group was fed 0.6% CLA or 1% choice white grease. Carcass data, liver- and backfat-samples were collected at slaughter. Longissimus muscle area, 10th-rib backfat depth, last rib midline backfat depth, LM color, marbling, firmness and drip loss, and bacon collagen content were not altered by DDGS or CLA. Outer layer backfat iodine values were increased (P [less than or equal to] 0.05) with DDGS feeding and were 65.07, 69.75, and 74.25 for 0, 20, and 40% DDGS, respectively. Addition of CLA decreased (P [less than or equal to] 0.05) outer layer backfat iodine values from 71.11 to 68.31. Diets containing DDGS decreased (P [less than or equal to] 0.05) percent lean tissue contained in bacon from 48% for controls to 38% for pigs fed 40%. Abundance of fatty acid synthase, carnitine palmitoyl transferase Ia, acetyl-CoA-carboxylase, stearoyl-CoA desaturase, and glycerol-3-phosphate dehydrogenase mRNA in adipose or liver were not different (P > 0.05) for pigs fed DDGS. Feeding CLA decreased (P [less than or equal to] 0.05) the [[DELTA].sup.9] desaturase index in adipose tissue. The data indicate that decreased carcass firmness with DDGS feeding is not reflected by changes in lipogenic gene expression. Feeding 20% or more DDGS to finishing swine decreases bacon leanness, but inclusion of 0.6% CLA in the finishing diet can partially reverse these effects. Key words: conjugated linoleic acid, distiller grain, pork quality, swine

Both (n-3) long-chain PUFA (LCPUFA) and linoleic acid [LA, 18:2(n-6)] improve cardiovascular disease (CVD) risk factors, but a high-LA intake may weaken the effect of (n-3) LCPUFA. In a controlled, double-blind, 2 x 2-factorial 8-wk intervention, we investigated whether fish oil combined with a high- or Iow-LA intake affects overall CVD risk profile. Healthy men (n = 64) were randomized to 5 mL/d fish oil capsules (FO))mean intake 3.1 g/d (n-3) LCPUFA) or olive oil capsules (control) and to oils and spreads with either a high (S/B) or a low (R/K) LA content, resulting in a 7.3 g/d higher LA intake in the S/B groups than in the R/K groups. Diet, (n-3) LCPUFA in peripheral blood mononuclear cells, blood pressure (BP), heart rate (HR), and plasma CVD risk markers were measured before and after the intervention. FO lowered fasting plasma triacylglycerol (TAG) (P < 0.001) by 51% and 19% in the FO+R/K-group and FO+S/B-group, respectively, which was also reflected in postprandial TAG measured after the intervention (P < 0.01 ). Although a fat x FO interaction was found for monocyte chemoattractant protein-I, neither the FO nor fat intervention affected fasting plasma cholesterol, glucose, insulin, fibrinogen, C-reactive protein, interleukin-6, vascular cell adhesion molecule-I, P-selectin, oxidized LDL, cluster of differentiation antigen 40 ligand (CD40L), adiponectin, or fasting or postprandial BP or HR after adjustment for body weight changes. In conclusion, neither fish oil supplementation nor the LA intake had immediate pronounced effects on the overall CVD risk profile in healthy men, but fish oil lowered plasma TAG in healthy subjects with initially low concentrations. J. Nutr. 138: 1061-1066, 2008.

To maximize growth, farmed fish are fed high-fat diets, which can lead to high tissue lipid concentrations that have an impact on quality. The intake of conjugated linoleic acid (CLA) reduces body fat in mammals and this study was undertaken to determine the effects of dietary CLA on growth, composition, and postprandial metabolic variables in sea bream. Fish were fed 3 diets containing 48 g/100 g protein and 24 g/100 g fat, including fish oil supplemented with 0 (control), 2, or 4% CLA for 12 wk. Feed intake, specific growth rate, total body fat, and circulating somatolactin concentration were lower in fish fed CLA than in controls. Feed efficiency was greater in fish fed 2% CLA than in controls. Liver triglyceride concentrations were higher in fish fed 4% CLA and muscle triglyceride concentrations were lower in fish fed both CLA diets than in controls. Hepatic fatty acyl desaturase and elongase mRNA levels in fish fed CLA were lower than in controls. Metabolic differences between controls and CLA-fed fish were observed at 6 h but not at 24 h after the last meal, including lower postprandial circulating triglyceride concentrations, higher hepatic acyl-CoA-oxidase, and lower L-3-hydroxyacyl-CoA dehydrogenase activities in CLA-fed fish than in controls. Dietary CLA did not affect enzymes involved in lipogenesis including hepatic fatty acid synthase and malic enzyme, but it decreased glucose 6-phosphate dehydrogenase activity at 24 h, but not at 6 h after feeding. The data suggest that CLA intake in sea bream has little effect on hepatic lipogenesis, channels dietary lipid from adipose tissue to the liver, and switches hepatic mitochondrial to peroxisomal [beta]-oxidation.

Two experiments were conducted to determine the effectiveness of a rumen-protected CLA (pCLA) supplement and the impact of feeding this pCLA on carcass characteristics and tissue fatty acid composition of lambs. In Exp. 1, a CLA-80 preparation (80% pure CLA; contained similar proportions of cis-9, trans11, and trans-10, cis-12 CLA), protected against rumen degradation, was fed to sheep, and the proportion of CLA reaching the duodenum was determined. A 3 x 3 Latin square design was used with 3 diets (1.4 kg of concentrate-based control diet, the same control diet plus 22 g of CLA-80, or the same control diet plus 110 g of pCLA/d), 3 feeding periods, and 3 rumen and duodenally cannulated sheep (Mule x Charolais males, 10 mo of age, BW 55.3 [+ or -] 1.8 kg). After 7 d of feeding, sheep were ruminally infused with chromium EDTA and Yb acetate for 7 d, after which samples of duodenal digesta were collected every 6 h for 48 h to determine the quantity of CLA reaching the small intestine each day. The amounts of CLA cis-9, trans-11 and trans-10, cis-12, and combined isomers, flowing through the duodenum each day were greater (P = 0.01) in sheep fed pCLA. Approximately 65% of the pCLA avoided rumen biohy drogenation, with the ratio of the 2 main isomers remaining similar. In Exp. 2, 36 Mule x Charolais ewe lambs (approximately 13-wk old, average initial BW 29.3 kg) were fed 3 levels of the pCLA or Megalac, which were fed to provide an equivalent energy content at each pCLA level. Lambs were randomly assigned to 1 of 7 treatment groups, which were fed for 10 wk to achieve a growth rate of 180 g/d. Treatments included the basal diet and the basal diet plus 25, 50, or 100 g of pCLA/kg of diet or the equivalent amount of Megalac. In liver (P < 0.001) and all adipose tissue depots studied, the proportions of both CLA isomers increased (P = 0.02) with the amount of pCLA fed but were not altered with increasing of Megalac. Although there was no effect of treatment on cis-9, trans-11 CLA content, accumulation (P < 0.001) in the LM with increasing of pCLA supplementation was observed for the trans-10, cis-12 isomer. Although tissues had been enriched with CLA, there was no evidence of a reduction in adipose tissue or an increase in muscle mass in these sheep. However, an effect of pCLA on tissue fatty acid composition was consistent with an inhibition of stearoyl-CoA desaturase. Key words: carcass, conjugated linoleic acid, sheep

We studied the incorporation of the trans-11 vaccenic-1-[sup.13]C acid ([sup.13]C-VA) into milk and endogenous synthesis of cis-9, trans-11 conjugated linoleic acid (CLA) in lactating women. Subjects (n = 4) were 247 [+ or -] 30 d postpartum, weighed 70.8 [+ or -] 3.7 kg, breast-fed at least 6 times/d and consumed self-selected diets. After an overnight fast, they consumed the [sup.13]C-VA (2.5 mg/kg body wt). Milk samples were obtained by complete breast expression at 0, 2, 4, 8, 12, 18, 24, and 48 h post-[sup.13]C-VA ingestion. Lipid was extracted using chloroform:methanol. Fatty acids were methylated and converted to dimethyl disulfide and Diels-Alder derivatives before analysis by gas chromatography mass spectrometry. The mean [sup.13]C-enrichment of milk VA was 3.1% at 8 h and reached maximal enrichment of 7.6% at 18 h. The [sup.13]C enrichment of milk cis-9, trans-11 CLA reached a maximum of 0.4% at 18 h, confirming its conversion of VA to the [DELTA]9-desaturase enzyme product. In the subjects examined, a portion (

Several studies have shown that conjugated linoleic acid (CLA) supplementation can improve the plasma lipid profile and thereby probably decrease the risk for development of atherosclerosis. The aim of the present study was to compare the effects on plasma and organ lipids of different dietary forms of CLA: triacylglycerol (TAG), diacylglycerol (DAG), monoacylglycerol (MAG), and fatty acid ethyl esters (FAEEs). DAG-, MAG-, and FAEE-CLA were produced by enzymatic interesterifications and all supplements were composed of a 1:1 mixture of the 2 major CLA isomers: cis-9, trans-11 and trans-10, cis-12. Male Syrian Golden hamsters were fed mildly atherogenic diets (10 g butter/100 g, 0.1 g cholesterol/100 g) supplemented with 0.5 g CLA/100 g or without CLA (control) for 8 wk. Liver weights were greater in the TAG- and FAEE-CLA groups than in the control group. In general, the form of CLA did not differentially affect plasma or liver cholesterol or plasma lipoprotein cholesterol concentrations, but only the TAG-CLA group had a higher final plasma TAG concentration than the control group. Both CLA isomers were incorporated into plasma, livers, and spleens. The results of the present study suggest that the form in which CLA is supplemented in the diet does not affect hamster plasma and liver TAG concentrations. The TAG-CLA form, a frequently used form of supplemental CLA, increases plasma TAG concentrations. If similar effects occur in humans, supplemental TAG-CLA cannot be considered to be beneficial given the relation between plasma TAG and the development of atherosclerosis.

Animal studies consistently show that dietary conjugated linoleic acid (CLA) reduces mammary tumorigenesis including metastasis. Relatively low concentrations of CLA are required for those effects, and a threshold level exists above which there is no added reduction. We reasoned that the concentration of CLA required to effectively alter mammary tumor metastasis may be dependent on the type of dietary fat because select fatty acids can enhance or suppress normal or malignant cell growth and metastasis. For this study, the diets (a total of 12 different groups) differed in fatty acid composition but not in energy from fat (40%). In experiments involving spontaneous metastasis, mice were fed for 11 wk; in experiments in which mice were injected i.v. with tumor cells, they were fed for 7 wk. Mice were then assessed for the effect of CLA concentration on mammary tumorigenesis. Mammary tumor growth was not altered, but metastasis was significantly decreased when beef tallow (BT) replaced half of a defined vegetable fat blend (VFB). That blend reflects the typical fat content of a Western diet. In addition, that same VFB:BT diet lowered the concentration of CLA required to significantly decrease mammary tumor metastasis from 0.1% of the diet to 0.05%. A diet in which corn oil replaced half of the VFB did not lower the threshold from 0.1 to 0.05%. In vitro, the main fatty acid in vegetable oil, linoleic acid, reduced the efficacy of CLA toxicity on mammary tumor cells in culture. Alternatively, fatty acids normally found in BT, such as oleic, stearic, and palmitic acids, either did not change or enhanced the cytolytic effects of CLA isomers on mouse mammary tumor cells in culture. These data provide evidence that dietary BT, itself with negligible levels of CLA, may increase the efficacy of dietary CLA in reducing mammary tumorigenesis. KEY WORDS: * conjugated linoleic acid * mouse mammary tumor metastasis * beef tallow

Conjugated linoleic acids are a group of geometric and positional isomers of linoleic acid that decrease body fat in growing animals by a poorly understood mechanism. The objective of this study was to investigate the isomer-specific effect of CLA on the proliferation and differentiation of pig preadipocytes in primary culture. The effect of CLA on preadipocyte proliferation was determined using cleavage of the tetrazolium salt, WST-1, as a marker for proliferation. Preadipocyte number was decreased in a dose-dependent fashion by trans-12,cis-10 CLA (P < 0.05). No other fatty acid affected preadipocyte number. Differentiation was monitored on d 10 after induction morphologically, enzymatically, and by measuring the mRNA abundance of key adipogenic transcription factors. Both a crude CLA preparation containing a mixture of CLA isomers (CLA-mix) and the pure trans-10,cis-12 CLA isomer inhibited glycerol-3-phosphate dehydrogenase (GPDH) activity in a dose-dependent fashion, with trans-10,cis12 CLA being more potent (P < 0.01) than the CLA-mix. Cis-9,trans-11 CLA failed to decrease GPDH activity; however, increasing concentrations of cis-9,trans-11 CLA tended to blunt the inhibitory effect of trans-10,cis-12 CLA on GPDH activity (P < 0.09), suggesting that cis-9,trans-11 CLA may antagonize the action of trans10,cis-12 CLA in porcine adipocytes. Finally, the isomer-specific effect of CLA on adipogenic transcription factor gene expression was investigated. Trans-10,cis-12 CLA decreased expression of peroxisome proliferator-activated receptor [gamma] (PPAR[gamma], P < 0.01) and sterol regulatory element-binding protein-1c (SREBP-1c; P < 0.05) mRNA, while failing to alter the expression of CCAAT/enhancer binding protein [alpha] (C/EBP[alpha]) mRNA. Interestingly, both the CLA-mix and the trans-10,cis-12 CLA isomer increased the mRNA abundance of chicken ovalbumin upstream promoter transcription factor 1 (COUP-TF; P < 0.002). No other fatty acid affected COUP-TF mRNA levels. Collectively these data support the concept that CLA decreases fat accretion in pigs, in part by inhibiting preadipocyte proliferation and differentiation, with trans-10,cis-12 CLA being an active isomer eliciting these effects. Furthermore, trans-10,cis-12 CLA inhibits porcine preadipocyte differentiation by a mechanism that involves the down-regulation of PPAR [gamma] and SREBP-1c mRNA. This mechanism is independent of changes in C/EBP [alpha] mRNA abundance and may involve COUP-TF. Key Words: Adipogenesis, Chicken Ovalbumin Upstream Promoter Transcription Factor 1, Conjugated Linoleic Acid, Primary Culture, Swine

The chemical characteristics, fatty acid and conjugated linoleic acid (CLA) contents and cholesterol levels of some traditional Turkish cheeses that are consumed mostly in Turkey were determined in this study. The fatty acid and cholesterol contents and CLA amount of cheeses were analysed as methyl esters by gas chromatography. The aim of this study was to determine the nutritional profile of some Turkish cheeses produced by traditional methods. The major fatty acids of the cheeses were palmitic acid ([C.sub.16:0]) and oleic acid ([C.sub.18:1]). The saturated fatty acid content of samples changed between 60.80% and 76.57%, while the monounsaturated fatty acid content ranged from 21.42% to 34.05% and the polyunsaturated fatty acid content was between 1.47% and 3.59%. The CLA contents of the cheeses ranged from 0.44 to 1.04 g/ 100 g in fat. The cholesterol levels of the samples were determined as 44.6-147.69 mg/100 g in cheese. Keywords: Conjugated linoleic acid (CLA), cholesterol level, fatty acid composition, traditional Turkish cheeses

Nearly half of the U.S. adult population is overweight or obese, which may be related to increased energy intake combined with lack of physical activity. Obesity increases the risk of several chronic diseases including diabetes, coronary heart disease, hypertension, and stroke. Conjugated linoleic acids (CLA) were shown to decrease fat and increase lean mass in several animal studies. However, the effects of CLA in combination with exercise (Ex) on body composition have not been studied in an animal model. We examined the effect of a low concentration of either safflower oil as control (0.5%) or mixed isomers of CLA (0.4%) along with treadmill exercise on body composition in male Balb/C mice fed a high-fat diet (20% corn oil) in a 2 x 2 factorial design. CLA consumption lowered change in fat mass (P < 0.001) confirming the results of other studies, and change in fat mass decreased further (P < 0.001) with CLA and exercise. Change in lean mass did not increase with exercise alone; it increased, although not significantly, with CLA alone and increased significantly (P < 0.05) due to the combination of CLA and exercise. This effect was accompanied by decreased serum leptin levels and lower leptin mRNA expression in peritoneal fat (P < 0.001). Serum insulin, glucose, tumor necrosis factor (TNF)-[alpha], and interleukin-6 were lower in CLA-fed mice than in controls (P < 0.05), whereas serum TNF-[alpha] was increased by exercise (P < 0.05). Exercise increased oxygen consumption and energy expenditure when measured under resting conditions (P < 0.05). In summary, the combination of dietary CLA and exercise decreased fat mass and increased lean mass in mice fed a high-fat diet, and these effects may be related in part to decreased serum leptin and exercise-induced increases in oxygen consumption and energy expenditure. KEY WORDS: * conjugated linoleic acid * exercise * body fat * leptin

We studied the effects of conjugated linoleic acid (CLA) on metabolic and immunologic variables in lactating sows and piglets. Gestating sows (n = 16) were assigned to 1 of 2 weight- and parity-matched groups supplemented with 0% (C) or 0.5% (T) of a CLA preparation containing 50% CLA isomers. Supplementation started in late pregnancy and continued throughout lactation. At weaning, 80 piglets, half from each group of sows, were assigned to 0% CLA (C) or 0.5% CLA (T). Thus, there were four groups of 20 piglets: C-C, C-T, T-T, and T-C. Body weight and the number of piglets per litter at birth and weaning, and the chemical composition of colostrum did not differ among the groups. CLA affected the fatty acid composition of colostrum fat; palmitoleic and [gamma]-linolenic acid were significantly lower compared with controls, whereas eicosenoic and eicosatrienoic acids were significantly higher. Feeding CLA increased (P < 0.05) colostrum IgG in sows. Sows fed CLA had higher (P < 0.05) serum leptin, IgG, and lysozyme. Nursing piglets from CLA-fed sows had significantly higher (P < 0.01) serum lysozyme and IgG. Consumption of CLA did not affect postweaning growth. Postweaning piglets fed CLA (T-T, C-T) had a higher IgG titer at 25 d (P < 0.05) and 35 d (P < 0.01) after weaning. Serum lysozyme was also higher at 25 d (P < 0.05) in CLA-fed piglets (T-T, C-T). At 35 d, serum [alpha]-1 acylglicoprotein was lower (P < 0.05) in piglets fed CLA. Dietary CLA had a positive effect on immunologic variables in lactating sows and piglets. KEY WORDS: * conjugated linoleic acid * immune response * sows * piglets

Several analyses and tests are conducted to explain the benefits of the supplementation of the conjugated linoleic acid (CLA) and dietary calcium on in mice and humans. The cosupplementation of dietary calcium and CLA is shown to highly enhance the bone mass in mice.

Ingredients in food products that boost immunity are emerging today. Some of these ingredients include: probiotics, prebiotics (such as oligofructose and fructooligosaccharides) , beta-glucans, conjugated linoleic acid, and mushrooms. Details regarding the nutritional aspects of these items are discussed.

The impact of the dietary supplementation of cows on the nutritional benefits of yogurt is examined.