Polyunsaturated Fatty Acid Concentrates of Carp Oil: Chemical Hydrolysis and Urea Complexation

The aims of this study were to compare three treatments in the chemical hydrolysis reaction of bleached oil from carp (Cyprinus carpio) heads and to obtain polyunsaturated fatty acid concentrates by urea complexation. The three treatments were carried out with different oil:ethanol molar ratios. In the treatment with a 1:39 molar ratio, a higher yield of free fatty acids was found. These fatty acids were submitted to urea complexation (−10 °C for 20 h, and urea–fatty acid ratio of 4.5–1). There was a 31.4% increase in monounsaturated and polyunsaturated fatty acids (MUFA and PUFA) content and a 75% decrease in saturated fatty acids (SAF) content. An increase of 85.4% in the EPA + DHA content was found. The non-urea complexing fraction can be considered a rich source of MUFA and PUFA with a total amount of 88.9%.     

Dietary fish oil inhibits Δ6-desaturase activity in vivo

Liver Δ6-desaturase activity was determined in mice which were made deficient in (i) n-6 and n-3 polyunsaturated fatty acids (PUFA), (ii) n-6 PUFA, or (iii) arachidonic acid (AA). Initially, the mice were subjected to two cycles of a fasting (1 d)/refeeding (2–3 d) protocol in which they were refed an essential fatty acid-deficient (EFAD) diet during the refeeding period. This 1-wk fasting/refeeding protocol, referred to as F/R EFAD, produced a rapid and substantial decline in tissue n-3 and n-6 PUFA and a corresponding increase in n-9 fatty acids, notably oleic acid and Mead acid (20:3n-9). Combined liver Δ6-desaturase/elongase/Δ5-desaturase activities in vivo were quantified by measuring the conversion of ¹⁴C-linoleic acid (LA) to ¹⁴C-AA in mouse liver. Although F/R EFAD caused, as expected, a substantial decline in liver AA and LA content, the conversion of ¹⁴C-LA to ¹⁴C-AA was the same in these mice as in chow-fed controls (approximately 33–34%). Subsequent refeeding of F/R EFAD mice with an EFAD diet, supplemented with corn oil, restored tissue n-6 PUFA levels without altering the conversion of ¹⁴C-LA to ¹⁴C-AA. In contrast, refeeding with an EFAD diet, supplemented with fish oil, inhibited ¹⁴C-LA to ¹⁴C-AA conversion by 78%. Significantly, inhibition of conversion of ¹⁴C-LA to ¹⁴C-AA was maintained in F/R EFAD mice that were subsequently fed an EFAD diet supplemented with a 1:1 mixture of fish oil/corn oil. This latter protocol yielded a unique liver fatty acid composition in which AA was selectively depleted, whereas LA and the n-3 PUFA were increased. The data suggest that dietary n-3 C_20–22 PUFA negatively regulate the in vivo synthesis of n-6 PUFA at the level of the Δ6-desaturase.     

Genetic Ablation of CD36 Does not Alter Mouse Brain Polyunsaturated Fatty Acid Concentrations

In the brain, polyunsaturated fatty acids (PUFA), especially arachidonic acid and docosahexaenoic acid (DHA), are required for regulating membrane fluidity, neuronal survival and signal transduction. Since the brain cannot synthesize n-6 and n-3 PUFA de novo, they must be supplied from the blood. However, the methods of PUFA entry into the brain are not agreed upon. This study tested the necessity of CD36, a candidate transporter of unesterified fatty acids, for maintaining brain PUFA concentrations by comparing brain PUFA concentrations in CD36^−/− mice to their wild-type littermates. Because CD36^−/− mice have been reported to have impaired learning ability, the PUFA concentrations in different brain regions (cortex, hippocampus, cerebellum and the remainder of brain) were investigated. At 9 weeks of age, the brain was separated into the four regions and fatty acid concentrations in total and phospholipid classes of these brain regions were analyzed using thin layer and gas chromatography. There were no statistical differences in arachidonic acid or DHA concentrations in the different brain regions between wild-type and CD36^−/− mice, in total or phospholipid fractions. Concentrations of monounsaturated fatty acids were decreased in several phospholipid fractions in CD36^−/− mice. These findings suggest that CD36 is not necessary for maintaining brain PUFA concentrations and that other mechanisms must exist.     

Determination of Underivatized Long Chain Fatty Acids Using HPLC with an Evaporative Light-Scattering Detector

A high-performance liquid chromatographic method with an evaporative light-scattering detector has been developed for the separation and quantitative analysis of four underivatized long chain fatty acids in four different oil matrices. An isocratic elution mode using methanol/water/acetic acid and an Agilent Eclipse XDB-C18 analytical column was used. Calibration curves of the four fatty acids (FA) were well correlated (r ² > 0.999) within the range of 1–10 mg mL⁻¹ for linoleic acid, 0.8–10 mg mL⁻¹ for stearic acid and 0.5–10 mg mL⁻¹ for the other FA. Four oil samples were examined; camellia oil, olive oil, Brucea javanica oil and sesame oil. Good agreement was found with the standard gas chromatographic (GC) method. The proposed method offers distinct advantages over the official GC method; better separation and precision, and the sample components do not need to be derivatized.     

Free Fatty Acids Reduction in Waste Cooking Oil by Rhodosporidium toruloides and Simultaneous Carotenoids,Lipids, and PAL Enzyme Production in a Two-Phase Culture System

Waste cooking oil (WCO) is a problematic waste product that contains free fatty acids (FFAs), preventing it from being valorized easily as biodiesel and poses an environmental hazard if incorrectly disposed. The use of WCO as a carbon source for Rhodosporidium toruloides (R. toruloides) using a two-phase culture system is developed. The normal growth of R. toruloides when cultured in WCO (OD₆₀₀ 52) reveals its ability to use a hydrophobic substrate as the carbon source compared to glucose (OD₆₀₀ 51.9). Interestingly, the extracellular lipase activity when R. toruloides is grown on WCO is 14.4 U mL⁻¹ compared to when grown on glucose (2.4 U mL⁻¹). Additionally, FFA levels in WCO are reduced from 2% to 0.2% at end of fermentation, suggesting that R. toruloides can consume FFA. Furthermore, higher yield of beneficial products: β-carotene (4.57 µg mL⁻¹), torularhodin (4.2 µg mL⁻¹), fatty acids (1 mg mL⁻¹), and phenylalanine ammonia-lyase (PAL) enzyme (0.12 µmol mg⁻¹) are produced when WCO is the carbon source, compared to glucose (4.1 µg mL⁻¹ β-carotene, 3.0 µg mL⁻¹ torularhodin, 1 mg mL⁻¹ of fatty acids, and 0.096 µmol mg⁻¹ PAL enzyme). This is a first study that shows R. toruloides can grow on hydrophobic carbon source.     

The Influence of Polyunsaturated Fatty Acids on the Phospholipase D Isoforms Trafficking and Activity in Mast Cells

The impact of polyunsaturated fatty acid (PUFA) supplementation on phospholipase D (PLD) trafficking and activity in mast cells was investigated. The enrichment of mast cells with different PUFA including α-linolenic acid (LNA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), linoleic acid (LA) or arachidonic acid (AA) revealed a PUFA-mediated modulation of the mastoparan-stimulated PLD trafficking and activity. All PUFA examined, except AA, prevented the migration of the PLD1 to the plasma membrane. For PLD2 no PUFA effects on trafficking could be observed. Moreover, PUFA supplementation resulted in an increase of mastoparan-stimulated total PLD activity, which correlated with the number of double bonds of the supplemented fatty acids. To investigate, which PLD isoform was affected by PUFA, stimulated mast cells were supplemented with DHA or AA in the presence of specific PLD-isoform inhibitors. It was found that both DHA and AA diminished the inhibition of PLD activity in the presence of a PLD1 inhibitor. By contrast, only AA diminished the inhibition of PLD activity in the presence of a PLD2 inhibitor. Thus, PUFA modulate the trafficking and activity of PLD isoforms in mast cells differently. This may, in part, account for the immunomodulatory effect of unsaturated fatty acids and contributes to our understanding of the modulation of mast cell activity by PUFA.     

n-3 Polyunsaturated Fatty Acids and Atopy in Korean Preschoolers

Atopy is a growing problem for Korean children. Since eicosapentaenoic acid is a precursor of less active inflammatory eicosanoids, n-3 polyunsaturated fatty acids (PUFA) may have a protective effect on atopy. This study was undertaken to determine whether n-3 PUFA in red blood cells (RBC) is lower in atopic than in non-atopic preschoolers. Three hundred and eight Korean children aged 4–6 years were enrolled. Total RBC fatty acid composition was measured by gas chromatography. The prevalence of atopic dermatitis, allergic rhinitis, or asthma was 29%. Total RBC n-3 PUFA were lower in preschoolers with atopy than controls (9.8 ± 1.2 vs. 11.4 ± 1.6%; P < 0.05), while n-6 PUFA (33.0 ± 1.4 vs. 32.2 ± 1.0%; P < 0.05) and n-6/n-3 PUFA ratio (3.4 ± 0.6 vs. 2.8 ± 0.5; P < 0.05) were greater. The following factors were also associated with an increase in atopy: higher saturated fatty acids (39.6 ± 1.4 vs. 40.6 ± 1.9; P < 0.05) and arachidonic acid (15.3 ± 1.6 vs. 16.0 ± 2.9; P < 0.05), and lower total PUFA (43.8 ± 0.7 vs. 42.8 ± 1.4; P < 0.05) and omega-3 index (EPA + DHA; 9.1 ± 0.8 vs. 7.8 ± 0.5; P < 0.05) in RBC. Maternal history of atopy was a significant (P < 0.05) risk factor, while lactation was not. The results suggest that a reduced content of n-3 PUFA in the RBC membrane could play a role in early children atopy.     

Effect of a Seaweed Extract on Fatty Acid Accumulation and Glycerol-3-Phosphate Dehydrogenase Activity in 3T3-L1 Adipocytes

This study was to determine the effect of a seaweed Ascophyllum nodosum extract (SE) containing 220 mg g⁻¹ phlorotannins on differentiation and fatty acid accumulation in differentiating 3T3-L1 adipocytes. 3T3-L1 cells (2 × 10⁴ mL⁻¹) were seeded to 24-well plates and proliferated to reach confluence and then were treated with media containing 0, 12.5, 25, 50, 75 and 100 μg mL⁻¹ SE for 8 days. Dexamethasone, methyl-isobutylxanthine and insulin (DMI) were added to the media in the first 2 days to induce cell differentiation. On day 8 the adipocytes were harvested for measuring cellular fatty acid concentration and the activity of glycerol-3-phosphate dehydrogenase (GPDH). It was found that treatment with SE increased (P < 0.01, n = 6) cellular myristoleic acid (C14:1), palmitoleic acid (C16:1) and oleic acid (C18:1) and total monounsaturated fatty acids (MUFA) without significantly affecting the cell number and saturated fatty acid (SFA). Ratios of MUFA/SFA, C14:1/C14:0, C16:1/C16:0 and C18:1/C18:0 in cellular lipids increased (P < 0.05, n = 6) with the SE treatment in a dose dependent manner (P < 0.001). Treatment with 75 μg mL⁻¹ SE depressed (P < 0.05) cellular GPDH activity. The results indicate that the biological factors in the SE may be involved in differentiation and MUFA accumulation in adipocytes.     

Fluorescence Enhancement Effect for the Determination of Nucleic Acids With Morin–NanoTiO<Subscript>2</Subscript>

It is found that nucleic acids can greatly enhance the fluorescence intensity of morin–nanoTiO₂. Under optimum conditions, the enhanced fluorescence intensity of the system is in proportion to the concentration of nucleic acids in the range of 2.0 × 10⁻⁸ to 2.2 × 10⁻⁷ g mL⁻¹ for calf thymus DNA (ctDNA) and 1.0 × 10⁻⁸ to 2.5 × 10⁻⁷ g mL⁻¹ for yeast RNA (yRNA). The detection limits are 4.8 × 10⁻⁹ g mL⁻¹ for ctDNA and 1.2 × 10⁻⁹ g mL⁻¹ for yRNA, respectively. This method has satisfactorily been used for the determination of nucleic acids in actual sample.     

Dietary arachidonic and linoleic acids: Comparative effects on tissue lipids

The effects of preformed dietary arachidonic acid (AA, 20∶4n−6) on murine phospholipid fatty acid composition in tissues capable (liver) and incapable (peritoneal exudate cells, PEC) of desaturating and elongating linoleic acid (LA, 18∶2n−6) to AA were investigated. The results were compared with those obtained on matched animals on LA diets by either substituting or supplementing dietary LA with AA. Modest amounts of AA ethyl ester (0.5 wt%) included in the diet significantly increased tissue phospholipid AA levels by 39% and 57% in the liver and in PEC, respectively. The changes were further enhanced when dietary LA and AA intakes were equivalent,i.e., 57% and 68% in liver and PEC, respectively. This enrichment was observed in all phospholipid classes analyzed, with the greatest impact on phosphatidylcholine. In addition, the doubling of dietary LA had little effect on tissue phospholipid AA levels. The data suggest that while the level of n−6 PUFA may have an important effect on tissue fatty acid composition, the type of n−6 PUFA in the diet could be of greater significance.     

Novel bismuth/multi-walled carbon nanotubes-based electrochemical sensor for the determination of neuroprotective drug cilostazol

A very sensitive electrochemical sensor has been developed by modification of glassy carbon electrode (GCE) with nanoparticles of bismuth (III) oxide (Bi₂O₃) and multi-walled carbon nanotubes (MWCNTs). The sensor was applied for the determination of cilostazol, cyclic nucleotide phosphodiesterase inhibitors in pharmaceutical formulation and human plasma. The voltammetric responses were compared with those obtained at bare GCE under optimum conditions. The cyclic and square-wave voltammograms of cilostazol showed 3.3 and 4.9 times enhancement in the oxidation peak current at MWCNTs–Bi₂O₃/GCE as compared to a bare GCE. Bi₂O₃–MWCNTs/GCE showed a linear response for cilostazol in standard solution over the concentration range of 0.8–13 μg mL⁻¹ with the detection limit 0.76 μg mL⁻¹, whereas human plasma over the concentration range 0.8–12.5 μg mL⁻¹ with the detection limit 0.66 μg mL⁻¹.     

Molecular evidence that the rate-limiting step for the biosynthesis of arachidonic acid in <Emphasis Type="Italic">Mortierella alpina</Emphasis> is at the level of an elongase

The oil-producing fungus Mortierella alpina 1S-4 is an industrial strain for arachidonic acid (AA) production. To determine its physiological properties and to clarify the biosynthetic pathways for PUFA, heterologous and homologous gene expression systems were established in this fungus. The first trial was performed with an enhanced green fluorescent protein gene to assess the transformation efficiency for heterologous gene expression. As a result, strong fluorescence was observed in the spores of the obtained transformant, suggesting that the foreign gene was inherited by the spores. The next trial was performed with a homologous PUFA elongase (GLELOp) gene, this enzyme having been reported to catalyze the elongation of GLA (18∶3n−6) to dihomo-γ-linolenic acid (20∶−6), and to be the rate-limiting step of AA production. The FA composition of the transformant was different from that of the host strain: The GLA content was decreased whereas that of AA was increased. These data support the hypothesis that the GLELOp enzyme plays an important role in PUFA synthesis, and may indicate how to control PUFA biosynthesis.     

Electrochemical Sensor for Detection of Trichlorfon Based on Molecularly Imprinted Sol–Gel Films Modified Glassy Carbon Electrode

Thin films of molecularly imprinted sol–gel polymer with specific binding sites for trichlorfon were prepared, fixed on glassy carbon electrodes and used as recognition material. The binding characteristic of the imprinted films to trichlorfon was evaluated by equilibrium binding experiments; and, the morphology was studied by scanning electronic microscope. A novel electrochemical sensor for determination of trichlorfon was developed based on the reaction between trichlorfon and the molecularly imprinted sol–gel film, which was a modified glassy carbon electrode. The sensor displayed excellent selectivity and high sensitivity. The linear response range of the sensor was 10⁻⁸ –10⁻⁶ g mL⁻¹, and the limit of detection was 2.8 × 10⁻⁹ g mL⁻¹. The relative standard deviation for the determination of 10⁻⁷ g mL⁻¹ trichlorfon was 3.5%. The sensor was applied to the determination of trichlorfon in vegetables with satisfactory results.     

One-Step Extraction and Concentration of Polyunsaturated Fatty Acids from Fish Liver

The fatty acids (FA) eicosapentaenoic acid (20:5ω-3; EPA) and docosahexaenoic acid (22:6ω-3; DHA), which have several health benefits, have been concentrated from mako shark liver (Isurus oxyrinchus). The process was carried out in one single step, in which fish liver oil was simultaneously extracted, saponified and concentrated. Additionally, the polyunsaturated fatty acids (PUFA) concentrate was winterized to crystallize the remaining saturated FA, resulting in a further increase in the concentration of DHA and EPA. Two variables, temperature and water concentration in the saponification mixture, were optimized to increase the concentration of ω-3 PUFA. Best results were obtained at 12 °C and 0% water content in the mixture, obtaining 17.8% purity and 77.6% yield of EPA; DHA purity and yield were 33.3 and 82.2%, respectively.     

Production of Polyunsaturated Fatty Acids by Mortierella alpina Using Submerse and Solid State Fermentation

A new isolate of Mortierella alpina, &#62; 98 % identical with M. alpina ATCC 16266, was cultivated in a defined glucose‐based medium with three organic nitrogen sources (glycine, urea and Na‐L‐glutamate) at three different concentrations in shaking flasks at 20 °C. The results were compared to the cultivation in complex medium with yeast extract as nitrogen source. In the defined media, high yields of polyunsaturated fatty acids (PUFAs) and arachidonic acid (ARA), respectively, were obtained with Na‐L‐glutamate. However, the absolute highest yields of PUFA and ARA were measured with the yeast extract medium. An optimized yeast extract complex medium was used for a submerse bioreactor cultivation in a 45‐L scale. Furthermore, M. alpina was cultivated in a solid state fermenter, using an oat bran water mixture as substrate.     

5c, 11c, 14c-Eicosatrienoic acid and 5c, 11c, 14c, 17c-eicosatetraenoic acid ofBiota orientalis seed oil affect lipid metabolism in the rat

The effects of 5c, 11c, 14c-eicosatrienoic acid (20∶3BSO) and 5c, 11c, 14c, 17c-eicosatetraenoic acid (20∶4BSO), polyunsaturated fatty acids (PUFA) contained inBiota orientalis seed oil (BSO), on lipid metabolism in rats were compared to the effects of fats rich in linoleic acid (LA) or α-linolenic acid (ALA) under similar conditions. The potential effect of ethyl 20∶4BSO as an essential fatty acid also was examined in comparison with the ethyl esters of LA. ALA and γ-linolenic acid (GLA). BSO- and ALA-rich fat decreased the concentration of plasma total cholesterol, high density lipoprotein cholesterol, triglyceride and phospholipid as compared to LA-rich fat. BSO was more effective in reducing plasma cholesterol concentrations than was the ALA-rich fat. Dietary BSO markedly decreased the hepatic triglyceride concentration as compared to the LA-rich or ALA-rich fats. Aortic production of prostaglandin I₂ tended to decrease in rats fed BSO or ALA-rich fat compared to those fed the LA-rich fat. Adenosine diphosphate-induced platelet aggregation was similar in the three groups. The proportion of arachidonic acid (AA) in liver phosphatidylcholine (PC) of rats fed BSO was lowest compared to that of rats fed ALA-rich or LA-rich fats. Administration of 20∶4BSO, ALA or GLA to essential fatty acid-deficient rats decreased the ratio of 20∶3n−9 to AA in liver PC to the same extent; administration of LA was more effective. The results indicate that the effects of specific PUFA contained in BSO on lipid metabolism are different from those of LA and ALA. It is also suggested that 20∶4BSO may exhibit some essential fatty acid effects.     

Pea (<Emphasis Type="Italic">Pisum</Emphasis><Emphasis Type="Italic">sativum</Emphasis> L.) Seeds as an Alternative Dietary Protein Source for Broilers: Influence on Fatty Acid Composition,Lipid and Protein Oxidation of Dark and White Meats

An experiment was conducted to evaluate the production parameters, breast and leg muscle fatty acid composition and lipid and protein oxidative stability of broilers fed peas (Pisum sativum L.). The trial involved 120 birds (Hubbard strain) allotted to two groups: group I—control group, fed a basal diet containing soybean meal (195 g kg⁻¹) as the main protein source; whereas group II—experimental group fed diet containing peas (400 g kg⁻¹) as a substitute for conventional soybean. No significant differences were observed for body weight, feed intake or feed conversion ratio (P > 0.05). The total lipids were lower (P < 0.05) in the breast and leg muscles of broilers fed peas. The content of total n-3 polyunsaturated fatty acids were higher (P < 0.05) in the white and dark meat of birds fed the pea diet compared with soybean control diet. After 7 days of refrigerated storage, the levels of thiobarbituric acid-reactive substances, lipid hydroperoxides and carbonyl proteins expressed as dinitrophenylhydrazine were similar (P > 0.05) in white and dark meat of chicks fed either diet. The data indicates that dietary pea inclusion does not cause detrimental changes in lipid and protein oxidation of poultry dark and white meats, suggesting the possibility of replacing soybean meal with peas.     

Cloning and Characterization of the ∆6 Polyunsaturated Fatty Acid Elongase from the Green Microalga <Emphasis Type="Italic">Parietochloris incisa</Emphasis>

The very-long-chain polyunsaturated fatty acid (VLC-PUFA), arachidonic acid (ARA, 20:4ω-6) is a component of neuron tissues such as brain and retina cells and a primary substrate for the biosynthesis of biologically active eicosanoids. The green freshwater microalga Parietochloris incisa (Trebouxiophyceae) has been shown to accumulate an extraordinary high content of ARA-rich triacylglycerols. It was thus interesting to characterize the genes involved in lipid biosynthesis in this alga. We report here the identification of a cDNA encoding for a P. incisa PUFA elongase (PiELO1) and demonstrate that the expression of PiELO1 in yeast Saccharomyces cereviseae confers its elongase activity on C18 ∆6 PUFA. Phylogenetic analysis indicated that PiELO1 is highly similar to functionally characterized ∆6 PUFA elongase genes from other green algae and lower plants. Quantitative real-time PCR expression studies showed that PiELO1 is upregulated under nitrogen starvation, the condition triggering and enhancing storage oil and ARA accumulation in P. incisa.     

Decreased production of inflammatory mediators in human osteoarthritic chondrocytes by conjugated linoleic acids

Osteoarthritic chondrocytes (OC) produce excessive prostaglandin E₂ (PGE₂) and nitric oxide (NO), which function as inflammation mediators in the pathogenesis of osteoarthritis (OA). This study examined the effect of CLA alone and in combination with other PUFA on the FA composition and the production of PGE₂ and NO in OC cultures isolated from OA patients. Human OC were grown in monolayer and treated with one of the following PUFA treatments: CLA, CLA+arachidonic acid (CLA/AA), CLA_EPA (CLA/EPA), linoleic acid (LA), LA+AA (LA/AA), LA+EPA (LA/EPA), and ethanol (as a vehicle control) at 10 and 20 μM for 6 d. Supplementation of PUFA at 10 μM for 6 d did not introduce any cytotoxic effects or morphological changes in OC, whereas 20 μM resulted in apoptosis. Cultures of OC treated with CLA, CLA/AA, and CLA/EPA had higher concentrations of CLA isomers, and these isomers were not detected in other treatments. Supplementation of CLA or LA alone to the OC led to a lower PGE₂ production compared to the control. Combination of CLA/EPA resulted in the lowest PGE₂ production in cultured OC. OC cultures treated with CLA were lower in NO production than the control, whereas the LA/AA treatment demonstrated the lowest NO production. The fact that CLA alone or in combination with other PUFA modulated PGE₂ and NO production in human OC cultures suggests that these 18∶2 isomers may have the potential to influence OA pathogenesis.     

Peripheral Artery Disease Is Associated with a Deficiency of Erythrocyte Membrane n-3 Polyunsaturated Fatty Acids

Population-based data suggest that individuals who consume large dietary amounts of n-3 polyunsaturated fatty acids (PUFA) have lower odds of peripheral artery disease (PAD); however, clinical studies examining n-3 PUFA levels in patients with PAD are sparse. The objective of this study is to compare erythrocyte membrane fatty acid (FA) content between patients with PAD and controls. We conducted a cross-sectional study of 179 vascular surgery outpatients (controls, 34; PAD, 145). A blood sample was drawn and the erythrocyte FA content was assayed using capillary gas chromatography. We calculated the ratio of the n-3 PUFA eicosapentaenoic acid (EPA) to the n-6 PUFA arachidonic acid (ARA) as well as the omega-3 index (O3I), a measure of erythrocyte content of the n-3 PUFA, EPA, and docosahexaenoic acid (DHA), expressed as a percentage of total erythrocyte FA. Compared with controls, patients with PAD smoked more and were more likely to have hypertension and hyperlipidemia (p < 0.05). Patients with PAD had a lower mean O3I (5.0 ± 1.7% vs 6.0 ± 1.6%, p < 0.001) and EPA:ARA ratio (0.04 ± 0.02 vs 0.05 ± 0.05, p < 0.001), but greater mean total saturated fats (39.5 ± 2.5% vs 38.5 ± 2.6%, p = 0.01). After adjusting for several patient characteristics, comorbidities, and medications, an absolute decrease of 1% in the O3I was associated with 39% greater odds of PAD (odds ratio [OR] 1.39, 95% confidence interval [CI] 1.03–1.86, and p = 0.03). PAD was associated with a deficiency of erythrocyte n-3 PUFA, a lower EPA:ARA ratio, and greater mean total saturated fats. These alterations in FA content may be involved in the pathogenesis or development of poor outcomes in PAD.