Dietary Olive Research Articles

Effects of dietary olive oil on growth performance, carcass parameters, serum characteristics, and Fatty Acid composition of breast and drumstick meat in broilers.

This experiment was conducted to evaluate the effects of dietary olive oil on growth performance, carcass parameters, serum characteristics, and fatty acid composition of breast and drumstick meat in broiler chickens. A total of 480 broilers were randomly allotted into three dietary treatments, including T (basal diet, 5% tallow), O1 (2% olive oil+3% tallow), and O2 (5% olive oil). During d 0 to 21, broilers fed the diet supplemented with 5% olive oil showed lower (p<0.05) body weight gain (BWG) and feed intake (FI) compared with those fed the T diet. Serum triglyceride concentration was reduced (p<0.05), while high density lipoprotein (HDL)-cholesterol concentration was increased (p<0.05) in the O2 treatment group compared with the T and O1 treatment groups. The addition of olive oil to the diets induced a reduction (p<0.05) in the total saturated fatty acid (SFA) contents in breast and drumstick meat, and increased (p<0.05) the total unsaturated fatty acid (USFA) contents and USFA/SFA ratios. In conclusion, a diet with 5% olive oil could decrease BWG and FI of broilers during the starter period (wk 0 to 3), and cause an increase in the serum HDL-cholesterol level, while decreasing the serum triglyceride concentration. Furthermore, USFA level and USFA/SFA ratios in breast and drumstick meat were increased by dietary supplementation of 2 or 5% olive oil.

Effects of a polyphenol present in olive oil, oleuropein aglycone, in a murine model of intestinal ischemia/reperfusion injury

Dietary olive oil supplementation and more recently, olive oil phenols have been recommended as important therapeutic interventions in preventive medicine. Ole has several pharmacological properties, including antioxidant, anti-inflammatory, antiatherogenic, anticancer, antimicrobial, and antiviral and for these reasons, is becoming an important subject of study in recent years. The aim of this study was to investigate the effects of Ole aglycone on the modulation of the secondary events in mice subjected to intestinal IRI. This was induced in mice by clamping the superior mesenteric artery and the celiac trunk for 30 min, followed by release of the clamp, allowing reperfusion for 1 h. After 60 min of reperfusion, animals were killed for histological examination of the ileum tissue and immunohistochemical localization of proinflammatory cytokines (TNF-α and IL-1β) and adhesion molecules (ICAM-1 and P-sel); moreover, by Western blot analysis, we investigated the activation of NF-κB and IκBα. In addition, we evaluated the apoptosis process, as shown by TUNEL staining and Bax/Bcl-2 expressions. The results obtained by the histological and molecular examinations showed in Ole aglycone-treated mice, a decrease of inflammation and apoptosis pathway versus SAO-shocked mice. In conclusion, we propose that the olive oil compounds, in particular, the Ole aglycone, could represent a possible treatment against secondary events of intestinal IRI.

Semen Quality and Sperm Function Loss by Hypercholesterolemic Diet Was Recovered by Addition of Olive Oil to Diet in Rabbit

Fat increment (0.05% cholesterol, chol) in standard diet promoted a significant increase in serum and sperm membrane chol, which ultimately altered membrane-coupled sperm specific functions: osmotic resistance, acrosomal reaction, and sperm capacitation in White New Zealand rabbits. These changes were also associated with a reduction in motility percentage and appearance of abnormal sperm morphology. The present study was carried out to evaluate the effect of dietary olive oil (OO, 7% v/w) administration to several male hypercholesterolemic rabbits (hypercholesterolemic rabbits, HCR) with altered fertility parameters. These HCR males were achieved by feeding normal rabbits with a high-fat diet (0.05% chol). HCR were associated with a modest non-significant increase in body weight (standard diet, 4.08±0.17 Kg, versus high-fat diet, 4.37±0.24 Kg). Hypercholesterolemic rabbits presented a marked decrease in semen volume, sperm cell count, and percentage of sperm motility, associated with a significant increase in sperm cell abnormalities. Moreover, sperm capacitation measured by the characteristic phosphorylated protein pattern in and induced acrosomal reaction were also altered suggesting sperm dysfunction. However, the administration of OO (for 16 weeks) to rabbits that were fed with 50% of the high-fat diet normalized serum chol. Curiously, OO supply succeeded to attenuate the seminal and sperm alterations observed in HCR group. Administration of OO alone did not cause any significant changes in above mentioned parameters. These data suggest that OO administration to HCR male rabbits recovers the loss of semen quality and sperm functionality.

Mediterranean diet and the Spanish paradox. A hypothesis

The Spanish paradox is a phenomenon observed in Spain and some other Mediterranean countries by which the cardiovascular morbidity and mortality levels are dissociated from their cardiovascular risk factors. The Mediterranean diet has been proposed as the main reason for this dissociation, but dietary changes themselves are not enough to explain this situation. It has been recently discovered that Stearoil-CoA desaturase (SCD) is involved in the dissociation between a favourable atherogenic metabolic profile and the risk for arteriosclerosis. We propose a hypothesis that attempts to clarify the Spanish paradox. This hypothesis contemplates the essential role of dietary olive oil and its interaction with different SCD genetic patterns. Confirmation of this hypothesis could provide the basis for the design of clinical and preventive strategies against cardiovascular morbidity and mortality, as well as certain metabolic risk factors.

Dietary Monounsaturated Fatty Acids Intake and Risk of Skin Photoaging

BackgroundIntake of monounsaturated fatty acids has been reported to reduce oxidative stress, insulin resistance and related inflammatory processes and may thus protect from skin photoaging. The objective of this study was to investigate the association between the risk of photoaging, monounsaturated fatty acids intake and the sources of monounsaturated fatty acids.Methodology/Principal FindingsA cross sectional study was conducted within the framework of the SUVIMAX cohort. The survey included 1264 women and 1655 men aged between 45 and 60 years old. Dietary monounsaturated fatty acids intakes were estimated by dietary source through at least ten 24-h diet records completed during the first 2.5 years of the follow-up period. Severity of facial skin photoaging was graded by trained investigators at baseline during a clinical examination using a 6-grade scale illustrated by photographs. A lower risk of severe photoaging was associated with higher intakes of monounsaturated fatty acids from olive oil in both sexes. Strikingly, no association was found with intake of monounsaturated fatty acids from animal sources whether from dairy products, meat or processed meat.Conclusion/SignificanceThese findings support the beneficial effect of dietary olive oil or healthy diet habits associated with olive oil consumption on the severity of facial photoaging.

Lipid oxidation of stored eggs enriched with very long chain n−3 fatty acids, as affected by dietary olive leaves (Olea europea L.) or α-tocopheryl acetate supplementation

The antioxidant potential of dietary olive leaves or α-tocopheryl acetate supplementation on lipid oxidation of refrigerated stored hen eggs enriched with very long-chain n-3 fatty acids, was investigated. Ninety-six brown Lohmann laying hens, were equally assigned into three groups. Hens within the control group were given a typical diet containing 3% fish oil, whereas other groups were given the same diet further supplemented with 10 g ground olive leaves/kg feed or 200mg α-tocopheryl acetate/kg feed. Results showed that α-tocopheryl acetate or olive leaves supplementation had no significant effect on the fatty acid composition and malondialdehyde (MDA) levels of fresh eggs but reduced their lipid hydroperoxide levels compared to controls. Storage for 60 d decreased the proportions of polyunsaturated fatty acids (PUFAs) but increased those of monounsaturated fatty acids (MUFAs) in eggs from the control group, while had no effect on the fatty acid composition of the eggs from the other two groups, which showed decreased levels of lipid hydroperoxides and MDA. Therefore, the very long chain n-3 PUFAs in eggs were protected from undergoing deterioration partly by olive leaves supplementation and totally by α-tocopheryl acetate supplementation. In addition, incorporating tocopherols into eggs might also provide a source of tocopherols for the human diet.

Dietary lipid-dependent regulation of de novo lipogenesis and lipid partitioning by ketogenic essential amino acids in mice

Background:We have previously reported that dietary ketogenic amino acids (KAAs) modulate hepatic de novo lipogenesis (DNL) and prevent hepatic steatosis in mice. However, the dependence of the metabolic phenotypes generated by KAA on the type of dietary lipid source remains unclear.Objective:The aim of this study was to assess the effect of KAA combined with different dietary lipid sources on hepatic DNL and tissue lipid partitioning in mice.Design:We compared three different KAA-supplemented diets, in which a portion of the dietary protein was replaced by five major essential amino acids (Leu, Ile, Val, Lys and Thr) in high-fat diets based on palm oil (PO), high-oleic safflower oil (FO) or soy oil (SO). To compare the effects of these diets in C57B6 mice, the differential regulation of DNL and dietary lipid partitioning due to KAA was assessed using stable isotopic flux analysis.Results:The different dietary oils showed strikingly different patterns of lipid partitioning and accumulation in tissues. High-PO diets increased both hepatic and adipose triglycerides (TG), whereas high-FO and high-SO diets increased hepatic and adipose TG, respectively. Stable isotopic flux analysis revealed high rates of hepatic DNL in high-PO and high-FO diets, whereas it was reduced in the high-SO diet. KAA supplementation in high-PO and high-FO diets reduced hepatic TG by reducing the DNL of palmitate and the accumulation of dietary oleate. However, KAA supplementation in the high-SO diet failed to reduce hepatic DNL and TG. Interestingly, KAA reduced SO-induced accumulation of hepatic linoleate and enhanced SO-induced accumulation of dietary oleate.Conclusions:Overall, the reduction of hepatic TG by KAA is dependent on dietary lipid sources and occurs through the modulation of DNL and altered partitioning of dietary lipids. The current results provide further insight into the underlying mechanisms of hepatic lipid reduction by amino acids.

Dietary Oleate Has Beneficial Effects on Every Step of Non-Alcoholic Fatty Liver Disease Progression in a Methionine- and Choline-Deficient Diet-Fed Animal Model

BackgroundNon-alcoholic fatty liver disease (NAFLD) is increasingly recognized as a major cause of liver-related morbidity and mortality. The underlying mechanisms of disease progression remain poorly understood, and primary therapy of NAFLD is not yet established. We investigated the effects of dietary oleate on the development and progression of NAFLD in a methionine- and choline-deficient (MCD) diet-fed animal model.MethodsA total of 30 C57BL/6J mice were randomly divided into three groups (n=10 in each group) and fed various experimental diets for four weeks: chow, MCD diet, or OMCD (MCD diet with oleate, 0.5 mg/g/day). Liver samples were examined for steatohepatitis and fibrosis parameters and associated genes.ResultsAdditional dietary oleate dramatically reduced MCD diet-induced hepatic steatosis. Hepatic carbohydrate responsive element-binding protein was overexpressed in MCD diet-fed mice, and dietary oleate prevented this overexpression (P<0.001). Dietary oleate partially prevented MCD diet-induced serum level increases in aspartate aminotransferase and alanine aminotransferase (P<0.001, respectively). The mRNA expressions of hepatic monocyte chemoattractant protein 1, tumor necrosis factor-α and matrix metalloproteinase-9 were increased in MCD diet-fed mice, and this overexpression of inflammatory molecules was prevented by dietary oleate (P<0.001). Hepatic pericellular fibrosis was observed in MCD diet-fed mice, and dietary oleate prevented this fibrosis. Altogether, dietary oleate prevented MCD diet-induced hepatic steatosis, inflammation and fibrosis.ConclusionDietary oleate has beneficial effects in every step of NAFLD development and progression and could be a nutritional option for NAFLD prevention and treatment.

Oxidative stability and microbial growth of turkey breast fillets during refrigerated storage as influenced by feed supplementation with olive leaves, oregano and/orα-tocopheryl acetate

1. The aim of this study was to evaluate the inhibitory potential of feed supplementation with olive leaves, oregano and/or α-tocopheryl acetate on microbial growth and lipid oxidation of turkey breast fillets during refrigerated storage. 2. A total of 40 turkeys, allocated to 5 groups of 8 birds each, were fed on diets supplemented with olive leaves at 10 g/kg, oregano at 10 g/kg or α-tocopheryl acetate at 150 or 300 mg/kg. Following slaughter, fillets from breast were stored at 4°C in the dark for 12 d, and lipid oxidation and microbial growth were assessed. 3. Results showed that dietary olive leaves were more effective than oregano at inhibiting lipid oxidation, but were inferior to dietary supplementation of 300 mg α-tocopheryl acetate/kg. In turn, α-tocopheryl acetate supplementation at 150 mg/kg was effective at inhibiting lipid oxidation compared to the control but inferior to oregano supplementation. 4. Total viable counts, lactic acid bacteria, Enterobacteriaceae and psychrotrophic bacteria counts were all increased in breast fillets of all groups throughout the refrigerated storage. Diet supplementation with α-tocopheryl acetate had no effect on the bacterial counts recorded in the control group, but diet supplementation with olive leaves or oregano resulted in a decrease of all bacterial counts at d 2 of storage and thereafter; during this period, oregano was more effective at inhibiting bacterial growth compared with olive leaves. 5. Therefore, if shown clinically to be safe and having beneficial effects in vivo, olive leaves and oregano might be utilised in novel applications as nutritional supplements or functional food components.

Direct analysis of glucuronidated metabolites of main olive oil phenols in human urine after dietary consumption of virgin olive oil

In the present study we report on a UPLC-MRM validated method for the simultaneous direct analysis of main glucuronidated metabolites of olive oil phenols: tyrosol, hydroxytyrosol and its O-methyl metabolite homovanillyl alcohol in human urine after dietary olive oil ingestion. The developed method was linear within the concentration range 20–2000ng/mL with adequate recovery of analytes (>86%). Intra- and inter-day precision and accuracy were according to standard requirements for method validation criteria. Using the developed method, urinary concentrations and excretion rates of glucuronides of olive oil phenols were successfully estimated in an intervention study with 11 healthy volunteers supplemented with a dietary dose of virgin olive oil (VOO) (50mL). Therefore, about 13% of the consumed olive oil polyphenols were recovered in 24-h urine, where 75% of them were in the form of glucuronides (3′- and 4′-O-hydroxytyrosol glucuronides, 4′-O-glucuronides of tyrosol and homovanillyl alcohol) and 25% as free compounds.

Effect of dietary olive leaves and rosemary on microbial growth and lipid oxidation of turkey breast during refrigerated storage

Forty turkeys were allocated to five groups of eight birds each. One (control) was fed a basal diet while the others were fed diets supplemented with either olive leaves at 10 g/kg, rosemary at 10 g/kg, α-tocopheryl acetate at 150 or at 300 mg/kg feed. Following slaughter, fillets from the breasts of the birds were stored at 4 °C in the dark for 12 days and their lipid oxidation and microbial growth rate were monitored. Results showed that dietary olive leaves were more effective in inhibiting lipid oxidation of the breast fillets compared to rosemary, but inferior to the dietary supplementation of 300 mg α-tocopheryl acetate/kg. In turn, lipid oxidation was more effectively inhibited when the birds received α-tocopheryl acetate supplementation at 150 mg/kg compared to when the birds received no suppelementation, but inferior to rosemary supplementation. Total viable counts, lactic acid bacteria, Enterobacteriaceae and psychrotrophic bacterial counts were all increased in breast fillets of all groups throughout refrigerated storage. Diet supplementation with a basal level of α-tocopheryl acetate had no effect on the bacterial counts recorded in the control group, but diet supplementation with olive leaves or rosemary resulted in a decrease in all bacterial counts from day 2 of storage and thereafter. During this period olive leaves were more effective in inhibiting bacterial growth than rosemaryKeywords: Antioxidant additives, α-tocopherol, turkey meat, herbs, spices, meat quality

Antioxidant Activities of Hydroxytyrosol Main Metabolites Do Not Contribute to Beneficial Health Effects after Olive Oil Ingestion

Hydroxytyrosol (HOTYR) and tyrosol (TYR), main phenolic compounds of olive oil, have been reported to contribute to the prevention of cardiovascular diseases due to their antioxidant activities, e.g., protection of low-density lipoprotein (LDL) oxidation. Their bioavailability in humans is poor, and they are found in biological fluids mainly as conjugated metabolites. Low concentrations of free phenols are unlikely to explain the biological activities seen in humans after olive oil intake. In this context, antioxidant activities of conjugated metabolites, in a range of concentrations compatible with their dietary consumption, were evaluated. Concentrations of metabolites and their core compounds were estimated in an intervention study of 11 healthy volunteers whose diet was supplemented with 50 ml of virgin olive oil, using high-performance liquid chromatography coupled to mass spectrometry for the simultaneous analysis of 3'-O- and 4'-O-HOTYR-glucuronides and 4'-O-glucuronides of TYR and homovanillyl alcohol in human urine. Glucuronides and core compounds were tested for their chemical (hydrogen donation by 1,1-diphenyl-2-picrylhydrazyl free radical test) and in vitro biological (inhibition of Cu-mediated LDL oxidation) antioxidant activities at the concentration ranges observed in human biological fluids (range, 0.01-10 muM) after dietary olive oil consumption. None of the glucuronides displayed significant antioxidant activities at the concentrations tested.

Dietary Nitrate, Olive oil and Inflammatory Bowel Disease

Dietary Nitrate, Olive oil and Inflammatory Bowel Disease

Dietary olive oil effect on antioxidant status and fatty acid profile in the erythrocyte of 2,4-D- exposed rats

BackgroundOxidative stress produced by reactive oxygen species (ROS) has been linked to the development of several diseases such as cardiovascular, cancer, and neurodegenerative diseases. This study investigates the possible protective effect of extra virgin olive oil (EVOO), lipophilic fraction (OOLF) and hydrophilic fraction (OOHF) on oxidative stress and fatty acid profile of erythrocytes in 2,4-D treated rats.MethodsMale Wistar rats were divided randomly into eight groups: control (C), (2,4-D) at a dose of 5 mg/kg b.w., (2,4-D/EVOO) was given 2,4-D plus EVOO, (2,4-D/OOHF) that received 2,4-D plus hydrophilic fraction, (2,4-D/OOLF) treated with 2,4-D plus lipophilic fraction, (EVOO) that received only EVOO, (OOHF) was given hydrophilic fraction and (OOLF) treated with lipophilic fraction. These components were daily administered by gavages for 4 weeks.Results2,4-D treatment lead to decrease of antioxidant enzyme activities, namely, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) associated with a higher amount of MDA level. Erythrocyte membranes' fatty acid composition was also significantly modified with 2,4-D exposure. EVOO and hydrophilic fraction supplemented to rats with or not 2,4-D treatment enhanced the antioxidant enzyme activities and reduced the MDA level. However, lipophilic fraction did not show any improvement in oxidative damage induced by 2,4-D in spite its richness in MUFA and vitamins.ConclusionEVOO administered to 2,4-D-treated rats protected erythrocyte membranes against oxidative damage by means of preventing excessive lipid peroxidation to increase the MUFA composition and increase maintaining antioxidants enzymes at normal concentrations.

Effect of dietary olive leaves and/or α-tocopheryl acetate supplementation on microbial growth and lipid oxidation of turkey breast fillets during refrigerated storage

Abstract Thirty turkeys were allocated to five groups of six birds each. One group that served as control was fed a basal diet, while the others were fed diets supplemented with olive leaves at 5 or 10 g/kg, or α-tocopheryl acetate at 150 or 300 mg/kg. Following slaughter, fillets from breast were stored at 4 °C in the dark for 12 days, and lipid oxidation and microbial growth were assessed. Results showed that the incorporation of olive leaves in turkey diets increased ( P P P P

Dietary olive oil and corn oil differentially affect experimental breast cancer through distinct modulation of the p21Ras signaling and the proliferation-apoptosis balance

Extra-virgin olive oil (EVOO) has been hypothesized to have chemopreventive effects on breast cancer, unlike high corn oil (HCO) diets that stimulate it. We have investigated mechanisms of these differential modulatory actions on experimental mammary cancer. In 7,12-dimethylbenz(a)anthracene adenocarcinomas of rats fed a high EVOO, HCO and control diets (n = 20 for each group), we have analyzed the expression and activity of ErbB receptors, p21Ras and its extracellular signal-regulated kinase (ERK) 1/2, Akt and RalA/B effectors by immunoblotting analyses. We explored the Ha-ras1 mutation status by Southern blot, mismatch amplification mutation assay and sequencing, and the 3-hydroxy-3-methylglutaryl-coenzyme A reductase and squalene synthase messenger RNA expression by real-time polymerase chain reaction. We analyzed the tumor mitotic index, proliferating cell nuclear antigen (PCNA) levels, and apoptosis through Caspase-3 analysis and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling assays. Finally, we measured the 8-oxo-2'-deoxyguanosine levels. Non-parametrical statistics were used. The EVOO diet decreased Ras activation, downregulated the Ras/phosphatidyl inositol 3-kinase/Akt pathway and upregulated the Raf/Erk pathway, compared with the control. In contrast, the HCO diet did not modify Ras activity but rather enhanced the Raf/Erk pathway. The EVOO diet decreased the cleaved ErbB4 levels, compared with the HCO diet, increased apoptosis and diminished the mono-ubiquitylated PCNA levels, which is related to DNA damage. Tumors from rats fed the EVOO diet displayed a more benign phenotype, whereas those from rats fed the HCO diet were biologically more aggressive. In conclusion, high EVOO and corn oil diets exert their modulatory effects on breast cancer through a different combination of Ras signaling pathways, a different proliferation-apoptosis balance and probably distinct levels of DNA damage.

Dietary olive oil prevents carbon tetrachloride-induced hepatic fibrosis in mice

The specific purpose of this study was to investigate the effects of dietary olive oil on hepatic fibrosis induced by chronic administration of carbon tetrachloride (CCl(4)) in the mouse. In addition, the effects of oleic acid, a major component of olive oil, on activation of hepatic stellate cells (HSCs) were investigated in vitro. Mice were fed liquid diets containing either corn oil (control, AIN-93) or olive oil (6.25 g/L) throughout experiments. Animals were treated with CCl(4) for 4 weeks intraperitoneally. The mRNA expression of TGF-beta1 and collagen 1alpha2 (col1alpha2) in the liver was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR). The HSCs were isolated from mice, and co-cultured with either oleic acid (100 microM) or linoleic acid (100 microM) for 2 days. The expression of alpha-smooth muscle actin (alpha-SMA) was assessed by immunohistochemistry. In addition, the production of hydroxyproline was determined. Serum alanine aminotransferase levels and the mRNA expression of TGF-beta and collalpha2 were significantly reduced by treatment of olive oil. Dietary olive oil blunted the expression of alpha-SMA in the liverand liver injury and hepatic fibrosis were prevented by treatment of olive oil. The number of alpha-SMA positive cells was significantly lower in HSCs co-cultured with oleic acid than in those co-cultured with linoleic acid. Concentration of hydroxyproline in culture medium was significantly lower in cells co-cultured with oleic acid than in the control. Dietary olive oil prevents CCl(4)-induced tissue injury and fibrosis in the liver. Since oleic acid inhibited activation of HSCs, oleic acid may play a key role on this mechanism.

Effects of foal presence at milking and dietary extra virgin olive oil on jennet milk fatty acids profile

Twelve Ragusana jennets were studied to investigate the effects of dietary extra virgin olive oil and presence of the foal during milking on milk fatty acids (FA) profile. At 20, 50 the and 90 days post-foaling, each jennet was milked 4 times per day. The feeding system and the milking procedures are given by Alabiso et al. (2009). FA profiles of the composites from milkings without foals (1MNF+3MNF) and with foals (2MYF+4MYF) were analyzed by gas chromatography. Dietary oil had no significant effect on milk yield or fat content but increased the proportion of C18:1 (n-9) in milk. Jennet milk had a beneficial FA profile compared to bovine milk and thus would be suitable for consumption by infants suffering from cows milk protein allergy, however, augmentation of the long-chain n-3 polyunsaturated FA content warrants further study.

Physical Inactivity Differentially Alters Dietary Oleate and Palmitate Trafficking

OBJECTIVE— Obesity and diabetes are characterized by the incapacity to use fat as fuel. We hypothesized that this reduced fat oxidation is secondary to a sedentary lifestyle.RESEARCH DESIGN AND METHODS— We investigated the effect of a 2-month bed rest on the dietary oleate and palmitate trafficking in lean women (control group, n = 8) and the effect of concomitant resistance/aerobic exercise training as a countermeasure (exercise group, n = 8). Trafficking of stable isotope–labeled dietary fats was combined with muscle gene expression and magnetic resonance imaging–derived muscle fat content analyses.RESULTS— In the control group, bed rest increased the cumulative [1-13C]oleate and [d31]palmitate appearance in triglycerides (37%, P = 0.009, and 34%, P = 0.016, respectively) and nonesterified fatty acids (NEFAs) (37%, P = 0.038, and 38%, P = 0.002) and decreased muscle lipoprotein lipase (P = 0.043) and fatty acid translocase CD36 (P = 0.043) mRNA expressions. Plasma NEFA-to-triglyceride ratios for [1-13C]oleate and [d31]palmitate remained unchanged, suggesting that the same proportion of tracers enters the peripheral tissues after bed rest. Bed rest did not affect [1-13C]oleate oxidation but decreased [d31]palmitate oxidation by −8.2 ± 4.9% (P < 0.0001). Despite a decreased spontaneous energy intake and a reduction of 1.9 ± 0.3 kg (P = 0.001) in fat mass, exercise training did not mitigate these alterations but partially maintained fat-free mass, insulin sensitivity, and total lipid oxidation in fasting and fed states. In both groups, muscle fat content increased by 2.7% after bed rest and negatively correlated with the reduction in [d31]palmitate oxidation (r2 = 0.48, P = 0.003).CONCLUSIONS— While saturated and monounsaturated fats have similar plasma trafficking and clearance, physical inactivity affects the partitioning of saturated fats toward storage, likely leading to an accumulation of palmitate in muscle fat.

Inhibition of Stearoyl-Coenzyme A Desaturase 1 Dissociates Insulin Resistance and Obesity From Atherosclerosis

Stearoyl-coenzyme A desaturase 1 (SCD1) is a well-known enhancer of the metabolic syndrome. The purpose of the present study was to investigate the role of SCD1 in lipoprotein metabolism and atherosclerosis progression. Antisense oligonucleotides were used to inhibit SCD1 in a mouse model of hyperlipidemia and atherosclerosis (LDLr(-/-)Apob(100/100)). In agreement with previous reports, inhibition of SCD1 protected against diet-induced obesity, insulin resistance, and hepatic steatosis. Unexpectedly, however, SCD1 inhibition strongly promoted aortic atherosclerosis, which could not be reversed by dietary oleate. Further analyses revealed that SCD1 inhibition promoted accumulation of saturated fatty acids in plasma and tissues and reduced plasma triglyceride, yet had little impact on low-density lipoprotein cholesterol. Because dietary saturated fatty acids have been shown to promote inflammation through toll-like receptor 4, we examined macrophage toll-like receptor 4 function. Interestingly, SCD1 inhibition resulted in alterations in macrophage membrane lipid composition and marked hypersensitivity to toll-like receptor 4 agonists. This study demonstrates that atherosclerosis can occur independently of obesity and insulin resistance and argues against SCD1 inhibition as a safe therapeutic target for the metabolic syndrome.