Erythrocyte Fatty Acid Research Articles

N-3 pufa status predicts non-alcoholic fatty liver disease (NAFLD) in older Australians

s / Journal of Nutrition & Intermediary Metabolism 1 (2014) 1e55 9 4 School of Environmental& Life Sciences, UniversityofNewcastle, NSW,Australia E-mail: Edwina.Mingay@uon.edu.au (E. Mingay) Background/Aims: Restricting energy intake for weight management in older people is neither safe nor practical as nutrient depletion may result in impairment of an already compromised immune system. Alternative strategies to combat adiposity without pre-disposing older people to infectious diseases are warranted. n-3PUFA may play an important role through their impact on increased fat oxidation and reduced inflammation. This study aimed to examine the relationship between n-3PUFA status and anthropometric measures in an older population. Methods: Older adults (n 1⁄4 620; age 65-95 years; 56.3% females) from the Central Coast region, NSW, Australia were recruited. Anthropometric measurements, including height, weight, BMI, waist (WC) and hip circumference (HC) were taken. The fatty acid composition of erythrocyte membranes was analysed via GC to determine n-3PUFA status (%EPA plus % DHA). Results: A negative association was detected between n-3PUFA status and anthropometric measures: BMI (r 1⁄4 -0.08, p 60) suggestive of NAFLD. n-3PUFA status was significantly lower in participants with NAFLD compared to those NAFLD (p < 0.05). A significant inverse relationship was found between n-3PUFA status and FLI (r 1⁄4 -0.153; p < 0.001). Sex differences were evident, with women but not men showing a significant association between n-3PUFA status and FLI (r 1⁄4 -0.192; p < 0.015). Conclusions: This study demonstrated a sex-dependent inverse relationship between n-3PUFA status and NAFLD in an older population, paving the way for an n-3PUFA intervention trial in this high risk age group. Funding source(s): ARC. BASELINE OMEGA-3 INDEX CORRELATES WITH AGGRESSIVE AND ATTENTION DEFICIT BEHAVIOURS IN ADULT PRISONERS B.J. Meyer , M.K. Byrne , C. Collier , N. Parletta , D. Crawford , P.C. Winberg , D. Webster , K. Chapman , G. Thomas , J. Dally , M. Batterham , I. Farquhar , L. Grant . 1 School of Medicine, University of Wollongong (UOW), NSW, Australia; 2 School of Psychology, UOW, NSW, Australia; 3 South Coast Correctional Centre, Nowra, NSW, Australia; 4 School of Population Health, University of South Australia, Australia; Venus Shell Systems, NSW, Australia; 6 Statistical Consulting Service, UOW, Australia; NSW Department of Corrective Services, Australia E-mail: bmeyer@uow.edu.au (B.J. Meyer) Background/Aims: There is no published data on the omega-3 index in prison populations in relation to mental health. We aim to determine if the variance of the baseline omega-3 index is correlated with aggressive and attention deficit behaviours in a prison population. Methods: One hundred and thirty six adult male prisoners were recruited from South Coast Correctional Centre (SCCC), NSW Australia. A 7-point categorisation was used to quantify levels of aggressive behaviour (four weeks) from individual SCCC case notes, whereby higher scores correspond to increasingly aggressive behaviour. At baseline, study participants completed an Aggression Questionnaire (AQ) and the Brown’s Attention Deficit Disorder Scales (BADDS), provided a blood sample for erythrocyte fatty acid analysis using GC and the omega-3 index was calculated. Results: The baseline omega-3 index ranged from 2.3% to 10.3% with a median of 4.7%, indicating that some participants already had substantial omega-3 intake. Assessment of aggressive and attention deficit behaviour shows that there were negative correlations between baseline omega-3 index and baseline aggression categorisation scores (r 1⁄4 0.21, p 1⁄4 0.016); total AQ score (r 1⁄4 0.234, p 1⁄4 0.011); Anger (r 1⁄4 0.222, p 1⁄4 0.016); Hostility AQ (r 1⁄4 0.239, p 1⁄4 0.009); indirect aggression (r 1⁄4 0.188 p 1⁄4 0.042); total BADDS (r 1⁄4 0.263, p 1⁄4 0.005); Activation (r 1⁄4 0.224, p 1⁄4 0.016); Attention (r 1⁄4 0.192, p 1⁄4 0.043); Effort (r 1⁄4 0.253, p 1⁄4 0.007); Affect (r 1⁄4 0.330, p < 0.001) and Memory (r 1⁄4 0.240, p 1⁄4 0.010). Conclusions: There is a high variability on baseline omega-3 status of a NSW prison population, and inmates with lower omega-3 index were more aggressive and had higher ADD scores. Funding source(s): UOW, NSW Department of Corrective Services. DISTINGUISHING THE NUTRITIONAL REQUIREMENTS AND PHYSIOLOGICAL FATE OF DIETARY EPA AND DHA IN ATLANTIC SALMON G.M. Turchini , J.A. Emery , J. Trushenski , F. Norambuena . 1 School of Life and Environmental Sciences, Deakin University, VIC, Australia; Center for Fisheries Aquaculture and Aquatic Sciences, Southern Illinois University

Erythrocyte phospholipid molecular species and fatty acids of Down syndrome children compared with non-affected siblings

The majority of children with Down syndrome (DS) develop Alzheimer's disease (AD) at an early age. Although long-chain n-3 fatty acids (FA) are protective of neurodegeneration, little is known about the FA status in DS. In the present study, we aimed to investigate whether children with DS presented altered plasma and erythrocyte membrane phospholipids (PL) FA composition, when compared with their non-affected siblings. Venous blood samples were analysed for plasma and erythrocyte membrane FA composition by TLC followed by GC techniques. Lipid molecular species were determined by electrospray ionisation/tandem MS (ESI-MS/MS). FA analysis measured by standard GC showed an increased concentration of MUFA and a decreased concentration of plasmalogens in major PL fractions, but there were no differences in the concentrations of arachidonic acid or DHA. However, as identified by ESI-MS/MS, children with DS had increased levels of the following erythrocyte PL molecular species: 16 : 0-16 : 0, 16 : 0-18 : 1 and 16 : 0-18 : 2n-6, with reduced levels of 16 : 0-20 : 4n-6 species. Children with DS presented significantly higher levels of MUFA in both plasma and erythrocyte membrane, as well as higher levels of saturated and monounsaturated molecular species. Of interest was the almost double proportion of 16 : 0-18 : 2n-6 and nearly half the proportion of 16 : 0-20 : 4n-6 of choline phosphoacylglycerol species in children with DS compared with their non-affected siblings. These significant differences were only revealed by ESI-MS/MS and were not observed in the GC analysis. Further investigations are needed to explore molecular mechanisms and to test the association between the pathophysiology of DS and the risk of AD.

Lipidomic analysis of fatty acids in erythrocytes of coeliac patients before and after a gluten-free diet intervention: a comparison with healthy subjects

Coeliac disease (CD) patients may exhibit a pro-inflammatory profile and fatty acids (FA) can influence inflammation through a variety of cellular pathways in them. The aims of the present study were to (1) evaluate the FA composition of erythrocytes obtained from newly diagnosed CD patients by lipidomic analysis and compare it with that in healthy subjects and (2) determine the effects of 1-year gluten-free diet (GFD) intervention. A total of twenty CD patients (five men and fifteen women; mean age 34.0 (sem 1.7) years) were evaluated at diagnosis and after 1 year of GFD intervention. A total of twenty healthy subjects (seven men and thirteen women; mean age 40.2 (sem 2.5) years) served as controls. CD patients on an unrestricted diet exhibited a significant 2.08-fold higher concentration of arachidic acid when compared with healthy subjects, suggesting that it can be considered as a putative marker of CD. Besides, the arachidonic acid (AA):dihomo-γ-linolenic acid ratio was 2.01-fold significantly lower in CD patients than in healthy subjects (P< 0.01), underlying an inefficient synthesis of PUFA from their precursors in terms of desaturase activity. In addition, mainly due to lower concentrations of docosahexaenoic acid, the inflammation marker AA:docosahexaenoic acid ratio was 1.40-fold significantly higher in CD patients than in healthy subjects. After 1 year of GFD intervention, FA concentrations in CD patients were still different from those observed in healthy subjects. The lipidomic analysis of erythrocyte membranes confirmed the presence of an altered FA composition in CD patients and the GFD's ability to modify FA profile, even if 1-year GFD intervention seems to be not sufficient to restore FA concentrations to normality. This procedure, being easier and non-invasive compared with the evaluation of the FA pattern of the intestinal mucosa, could offer more potentiality for also evaluating therapeutic interventions in CD patients by using FA supplementation.

Validation of fatty acid intakes estimated by a food frequency questionnaire using erythrocyte fatty acid profiling in the Montreal Heart Institute Biobank.

To improve the prevention, treatment and risk prediction of cardiovascular diseases, genetic markers and gene-diet interactions are currently being investigated. The Montreal Heart Institute (MHI) Biobank is suitable for such studies because of its large sample size (currently, n = 17 000), the availability of biospecimens, and the collection of data on dietary intakes of saturated (SFAs) and n-3 and n-6 polyunsaturated (PUFAs) fatty acids estimated from a 14-item food frequency questionnaire (FFQ). We tested the validity of the FFQ by correlating dietary intakes of these fatty acids with their red blood cell (RBC) content in MHI Biobank participants. Seventy-five men and 75 women were selected from the Biobank. We successfully obtained RBC fatty acids for 142 subjects using gas chromatography coupled to mass spectrometry. Spearman correlation coefficients were used to test whether SFA scores and daily intakes (g day(-1)) of n-3 and n-6 PUFAs correlate with their RBC content. Based on covariate-adjusted analyses, intakes of n-3 PUFAs from vegetable sources were significantly correlated with RBC α-linolenic acid levels (ρ = 0.23, P = 0.007), whereas n-3 PUFA intakes from marine sources correlated significantly with RBC eicosapentaenoic acid (ρ = 0.29, P = 0.0008) and docosahexaenoic acid (ρ = 0.41, P = 9.2 × 10(-7)) levels. Intakes of n-6 PUFAs from vegetable sources correlated with RBC linoleic acid (ρ = 0.18, P = 0.04). SFA scores were not correlated with RBC total SFAs. The MHI Biobank 14-item FFQ can appropriately estimate daily intakes of n-3 PUFAs from vegetable and marine sources, as well as vegetable n-6 PUFAs, which enables the possibility of using these data in future studies.

Effects of hypercholesterolemic diet enriched with onion as functional ingredient on fatty acid metabolism in Wistar rats

The complex biochemical composition of onions has been studied as a source of biological components with health-related properties. The evolution of hypercholesterolemia is associated with a large range of alterations considered as strong risk factors for many cardiovascular events. The objective of this study was to investigate the effects of onion as functional ingredient on plasma, erythrocyte, liver and adipose tissue fatty acid composition in hypercholesterolemic male Wistar rats. Rats (n=24) were randomly divided into three groups: control (C), high-cholesterol (HC), and high-cholesterol enriched with onion (HCO) groups. At the end of 7weeks, animals were anesthetized and euthanized by extracting blood by cardiac puncture. Plasma, erythrocytes, liver and adipose tissue were collected and immediately stored at −80°C. Fatty acid methyl esters were identified and quantified by GC/MS. Total fatty acid concentration decreased in liver and adipose tissue both in HC and HCO groups. SFA content was significantly higher in plasma, erythrocytes and liver in the C group compared to HC and HCO groups. In contrast, SFAs increased in adipose tissue both in HC and HCO groups compared to the C group. A significant increase in MUFA content in plasma was found in HC and HCO groups compared to the C group; in erythrocytes and liver the increase was lower. In plasma, PUFA content was significantly lower in HC and HCO groups compared to the C group. Interestingly, in liver and adipose tissue, PUFAs increased in HC and HCO groups compared to the C group. Results showed noticeable effects on individual fatty acid composition when assaying high-cholesterol diets in rats, in some cases enhanced by onion enrichment. Further research is needed to deeper understand the involved mechanisms and pathways.

Higher Erythrocyte n–3 PUFAs Are Associated with Decreased Blood Pressure in Middle-Aged and Elderly Chinese Adults

Previous studies suggested that blood fatty acids (FAs) might affect blood pressure (BP), but the findings have been inconclusive. This study evaluated the cross-sectional and prospective associations of erythrocyte FAs with BP in middle-aged and elderly Chinese individuals. Between 2008 and 2010, 1834 participants (1364 women and 470 men) aged 57 ± 5 y had baseline measurements taken of their erythrocyte FAs and BP. A total of 1477 participants (1103 women and 374 men) had their BP measured again after 3.09 ± 0.32 y (range: 2.91–3.26 y). In the cross-sectional analyses (n = 1834), the erythrocyte saturated FA (SFA) content was positively associated with BP, whereas total cis polyunsaturated FAs (PUFAs), their subtypes cis n–3 (ω-3) PUFAs and cis n–6 (ω-6) PUFAs, and the PUFA-to-SFA ratio were inversely associated with BP (all P-trends < 0.05). The longitudinal results (n = 1477) showed marginally inverse associations between cis n–3 PUFAs and the n–3:n–6 PUFA ratio and BP. For individual cis n–3 PUFAs, higher contents of 20:5n–3, 22:5n–3, and 22:6n–3 were significantly associated with reduced increases in SBP over time (the mean change range between quartile 4 and quartile 1 was −0.917 to −0.749 mm Hg for SBP; all P-trends < 0.01), and 20:5n–3 was inversely associated with DBP change (the mean change between quartile 4 and quartile 1 was −0.631; P-trend < 0.001). Path analyses suggested that the associations between cis n–3 PUFAs and BP might be mediated by decreasing serum triglycerides (TGs) and body mass index (BMI). Our findings revealed that a higher content of cis n–3 PUFAs (mainly very long-chain cis n–3 PUFAs) may benefit BP progress, probably mediated by decreasing serum TGs and BMI.

Associations between Omega-3 Index increase and triacylglyceride decrease in subjects with hypertriglyceridemia in response to six month of EPA and DHA supplementation

IntroductionIngestion of long-chain n-3 PUFA effectively decreases serum triacylglycerol (TAG) levels and increases the Omega-3 Index, defined as the % of EPA and DHA in erythrocyte fatty acids. However, it remains unclear whether there is a relationship between the Omega-3 Index increase (ΔO3I increase) and the TAG level decrease (ΔTAG). We hypothesized that TAG reduction is strongly depended on Omega-3 Index increase. Subjects and methodsSecondary analyses of data from a former double-blind placebo-controlled trial in which 150 dyslipidemic statin-treated subjects were randomized to four capsules of fish oil daily either as re-esterified TAG or ethylesters in identical doses (1.01g EPA+0.67g DHA) or corn oil as a placebo for a period of six month. Results108 subjects fulfilled the criteria of the current study protocol and were included in the analyses. A weak but significant negative correlation between ΔO3I and ΔTAG was observed (r=−0.211, p<0.05). However, the relation between ΔO3I and serum ΔTAG was not linear (coefficients of determination R2: 0.044). After sub-grouping the study population into Omega-3 Index response groups, the group with a mean ΔO3I of>4% after six months of n-3 PUFA treatment demonstrated the greatest TAG reduction. Discussion and conclusionsA weak association between Omega-3 Index increase and TAG level decrease was found. This may be explained by highly fluctuating TAG levels, a large inter-individual difference in response of the Omega-3 Index, a cohort of subjects with only slightly elevated TAG levels and high Omega-3 Index values at baseline, and possibly to insufficient statistical power. Since there was no strong association between Omega-3 Index increase and the TAG level decrease, we conclude that changes in serum TAG levels are not a viable substitute for the Omega-3 Index to monitor treatment with EPA and DHA.

Erythrocyte fatty acids as potential biomarkers in the diagnosis of advanced lung adenocarcinoma, lung squamous cell carcinoma, and small cell lung cancer.

To analyze the fatty acid profiles of erythrocyte total lipids from patients with advanced squamous cell lung carcinoma (SCC), lung adenocarcinoma (ADC), and small cell lung cancer (SCLC) and benign lung diseases (chronic obstructive pulmonary disease [COPD] and asthma) to reveal the fatty acids that could be used as lung cancer biomarkers. Thirty, 20, 15, 17, and 19 patients with SCC, ADC, SCLC, COPD, and asthma, respectively, and 55 healthy participants were enrolled in our study. Fatty acid profiles were investigated using gas chromatography/mass spectrometry followed by receiver operating characteristic (ROC) curve analysis. Sialic acid (SA) and cytokeratins were measured by the thiobarbituric acid and immunoradiometric methods, respectively. At least one of the main fatty acids might be used as a biomarker for every type of lung cancer: arachidonic (20:4n6), linoleic (18:2n6), and stearic (18:0) acids for ADC, SCC, and SCLC, respectively. These fatty acids showed diagnostic yields and operating characteristics similar to or higher than the commonly used SA or cytokeratin markers. Fatty acids from erythrocyte total lipids might be used as diagnostic biomarkers of lung ADC, SCC, and SCLC. Their use in different aspects of the disease process needs to be explored.

Correlation of Erythrocyte Trans Fatty Acids with Ovulatory Disorder Infertility in Polycystic Ovarian Syndrome

Trans fatty acids are considered to be the important modifiable factor of the ovulatory infertility disorder. The purpose of this study was to test the hypothesis that higher trans fatty acids of erythrocytes (RBC) are associated with the risk of ovulatory infertility disorder in polycystic ovarian syndrome (PCOS). Thirty five infertile women with polycystic ovarian syndrome, defined by AES criteria and 29 age-matched healthy women as a control group were recruited for the study. After physical measurements and nutritional assessment, blood samples were collected. Fasting serum glucose and insulin were measured, and then insulin resistance was calculated by homeostasis model assessment (HOMA-IR). Erythrocyte fatty acids were measured by gas chromatography. The patients group had higher waist circumference (WC), insulin levels, HOMA-IR than controls ( p &lt; 0.05). Also, case group had lower percentage of normal BMI (BMI&lt;25), physical activity and education levels than healthy women ( p &lt; 0.05). Among RBC trans fatty acids only trans linoleate (18:2t) were significantly higher in case group than control women ( p = 0.019). PCOS group tended to consume more food rich in TFAs than the control group. Logistic regression analysis also showed that only 18:2t is positively associated with risk of ovulatory disorder infertility in PCOS (OR= 1.225, 95% CI. 1.024-1.465; P = 0.026), which was not affected after adjustment for BMI, physical activity and education levels. The results suggested that RBC trans fatty acids might be a predictor of increased risk for ovulatory infertility disorder in women with PCOS.

Docosahexaenoic Acid and Periodontitis in Adults

Periodontitis is a common chronic inflammatory disease initiated by bacteria, resulting in bone resorption, tooth loss, and systemic inflammation. Long-chain omega-3 fatty acids such as docosahexaenoic acid (DHA) reduce periodontitis in animals. We aimed to determine whether DHA supplementation with low-dose aspirin would reduce periodontitis in humans. We conducted a double-blind placebo-controlled parallel trial lasting 3 mo. Fifty-five adults with moderate periodontitis were randomized to 2,000 mg of DHA or identical soy/corn oil capsules. All participants received 81 mg of aspirin but received no other treatments. We analyzed the primary outcome of per-pocket change in pocket depth using mixed models among teeth with pocket depth ≥5 mm. Secondary outcomes assessed with generalized estimating equations included gingival index, plaque index, and bleeding on probing. Gingival crevicular fluid samples were analyzed for changes in high-sensitivity C-reactive protein (hsCRP) and interleukins 6 and 1β (IL-6 and IL-1β). Plasma was analyzed for changes in systemic inflammatory markers, including hsCRP. We confirmed adherence with erythrocyte fatty acid measurement. Forty-six participants completed the trial. While similar at baseline, the proportion of DHA in red blood cell plasma membranes increased from 3.6% ± 0.9% to 6.2% ± 1.6% in the intervention group but did not change among controls. DHA supplementation decreased mean pocket depth (–0.29 ± 0.13; p = .03) and gingival index (–0.26 ± 0.13; p = .04). Plaque index and bleeding on probing did not change. Significant adjusted differences were found between DHA and control for both gingival crevicular fluid hsCRP (–5.3 ng/mL, standard error [SE] = 2.4, p = .03) and IL-1β (–20.1 pg/mL, SE = 8.2, p = .02) but not IL-6 (0.02 pg/mL, SE = 0.71, p = .98) or systemic hsCRP (–1.19 mg/L, SE = 0.90, p = .20). In this randomized controlled trial, aspirin-triggered DHA supplementation significantly improved periodontal outcomes in people with periodontitis, indicating its potential therapeutic efficacy (clinicaltrials.gov NTC01976806).

Elevated Plasma Retinol-Binding Protein 4 Is Associated with Increased Risk of Type 2 Diabetes in Middle-Aged and Elderly Chinese Adults1–3

The association between circulating retinol-binding protein 4 (RBP4) and risk of type 2 diabetes has been inconsistent in cross-sectional studies, but prospective evidence is limited. We aimed to investigate whether plasma RBP4 is associated with future development of type 2 diabetes and whether the association could be explained by iron or other risk factors. A total of 2091 Chinese adults aged 50–70 y were followed up for 6 y. Baseline dietary intakes and fasting plasma RBP4, ferritin, adiponectin, C-reactive protein (CRP), γ-glutamyltransferase, creatinine, and erythrocyte fatty acids were determined. Self-reported doctor-diagnosed diabetes, or usage of antidiabetic agents, or fasting plasma glucose concentration at the follow-up visit ≥7.0 mmol/L was defined as an incident diabetes case. Plasma RBP4 concentration was significantly associated with dietary heme iron intake, plasma ferritin concentration, and other established risk factors. After multivariate adjustment for demographic and lifestyle variables, relative risk (RR) for type 2 diabetes when the extreme quartiles of RBP4 were compared was 1.75 (95% CI: 1.30, 2.37; P-trend < 0.001). This association remained significant when the extreme quartiles were compared (RR = 1.48; 95% CI: 1.06, 2.05; P-trend = 0.036) after further controlling for ferritin and dietary factors, as well as other risk factors, including body mass index, adiponectin, CRP, lipids, liver and kidney function, insulin resistance, and hypertension. A threshold effect of RBP4 concentrations on incident diabetes was suggested by restricted quadratic spline analysis (P = 0.026 for nonlinearity). Our study indicates that plasma RBP4 is independently associated with the 6-y risk of developing type 2 diabetes.

The muscle mass, omega-3, diet, exercise and lifestyle (MODEL) study - a randomised controlled trial for women who have completed breast cancer treatment.

BackgroundLoss of lean body mass (LBM) is a common occurrence after treatment for breast cancer and is related to deleterious metabolic health outcomes [Clin Oncol, 22(4):281–288, 2010; Appl Physiol Nutr Metab, 34(5):950–956, 2009]. The aim of this research is to determine the effectiveness of long chain omega-3 fatty acids (LCn-3s) and exercise training alone, or in combination, in addressing LBM loss in breast cancer survivors.Methods/designA total of 153 women who have completed treatment for breast cancer in the last 12 months, with a Body Mass Index (BMI) of 20 to 35 kg/m2, will be randomly assigned to one of 3 groups: 3g/d LCn-3s (N-3), a 12-week nutrition and exercise education program plus olive oil (P-LC) or the education program plus LCn-3s (EX+N-3). Participants randomised to the education groups will be blinded to treatment, and will receive either olive oil placebo (OO+N-3) or LCn-3 provision, while the N-3 group will be open label. The education program includes nine 60-75min sessions over 12 weeks that will involve breast cancer specific healthy eating advice, plus a supervised exercise session run as a resistance exercise circuit. They will also be advised to conduct the resistance training and aerobic training 5 to 7 days per week collectively. Outcome measures will be taken at baseline, 12-weeks and 24-weeks. The primary outcome is % change in LBM as measured by the air displacement plethysmograhy. Secondary outcomes include quality of life (FACT-B + 4) and inflammation (C-Reactive protein: CRP). Additional measures taken will be erythrocyte fatty acid analysis, fatigue, physical activity, menopausal symptoms, dietary intake, joint pain and function indices.DiscussionThis research will provide the first insight into the efficacy of LCn-3s alone or in combination with exercise in breast cancer survivors with regards to LBM and quality of life. In addition, this study is designed to improve evidence-based dietetic practice, and how specific dietary prescription may link with appropriate exercise interventions.Trials registrationACTRN12610001005044; and World Health Organisation Universal trial number: U1111-1116-8520.

Intake of trans fatty acid isomers found in ruminant fat versus industrial sources differentially impact concentrations of fatty acids in erythrocytes (1025.17)

Evidence suggests concentration of trans fatty acids (TFA) in erythrocyte (RBC) membranes is strongly predictive of coronary heart disease (CHD) risk. Some data suggest a direct association with industrially‐produced TFA (iTFA) and CHD risk, and an inverse or no association with naturally‐occurring TFA in ruminant fat (rTFA). Differential incorporation of TFA isomers in RBC membranes from iTFA and rTFA may account for differences in CHD risk reported between the two sources; however, controlled dietary interventions comparing iTFA and rTFA have not measured RBC TFA isomers. In a double‐blind randomized‐controlled crossover feeding trial healthy adults (N=106; 47M, 59F) were fed 4 diets for 24 days each: 0.1% en mixed isomers TFA (control), 3.0% en highly‐purified vaccenic acid (VA), 3.0% en mixed isomers iTFA, and 1.0% en c9,t11‐CLA. Total fat (34% en) and other macronutrients were matched across diets. RBC VA was highest following the VA diet (P &lt; 0.05), while elaidic acid was highest following the iTFA diet (P &lt; 0.05). RBC c9,t11‐CLA was highest after the CLA diet (P &lt; 0.05), followed by the VA diet (P &lt; 0.05), indicating some conversion of VA to c9,t11‐CLA resulting from the dietary VA. In conclusion, highly‐purified dietary VA and c9,t11‐CLA differentially impact RBC fatty acid profiles compared to iTFA. Differences in RBC fatty acids impact membrane fluidity which may explain differences of rTFA and iTFA on CHD risk.Grant Funding Source: Supported by: USDA, Nestle, National Dairy Council, Dairy Australia

Correlation between erythrocyte pentadecanoic acid, dairy intakes, and cognitive function in participants of the Cache County Study on Memory, Health and Aging (628.13)

Background Diet plays an important role in the pathogenesis of Alzheimer’s disease (AD). Dietary fatty acids that are not synthesized in humans may serve as tissue markers for intakes of those source foods. A growing body of evidence supports that erythrocyte pentadecanoic acid (15:0) is a potential biomarker for dairy intake.Objective To investigate the associations between dairy intakes, erythrocyte 15:0, and cognitive function among elderly participants in the Cache County Study on Memory, Health and Aging.Design Erythrocyte fatty acids were profiled as a percentage of total fatty acids for 1987 nondemented subjects. Cognitive function was assessed with an adapted Modified Mini‐Mental State examination (3MS). Food intakes were surveyed with a 142‐item food frequency questionnaire and were adjusted by total energy using the residual method. Spearman partial correlations adjusted for age, gender and BMI were examined for erythrocyte 15:0, intake of individual dairy product, and 3MS score. Multivariable linear regression models were fit on dairy intakes with erythrocyte 15:0 as the outcome controlling for potential confounding factors.Results Erythrocyte 15:0 was positively associated with dietary intakes of 1‐2% milk (r = 0.12, p &lt; 0.001), whole milk (r = 0.28, p = 0.001), butter (r = 0.16, p &lt; 0.001), and cheese besides Cottage/Ricotta or cream cheese (r = 0.12, p &lt; 0.001) but was not associated with the intakes of skim/chocolate milk, (frozen) yogurt, ice cream, and Cottage/Ricotta/cream cheese. In multivariable regression models each increase in servings of whole milk, butter, 1‐2% milk, and cheese besides Cottage/Ricotta or cream cheese was associated with a 0.30, 0.16, 0.13, and 0.12 points increase on the erythrocyte 15:0 (p &lt; 0.001 for all). Erythrocyte 15:0 was not correlated with 3MS score.Conclusion Erythrocyte pentadecanoic acid is a biomarker for the consumption of less modified dairy products and is not correlated with 3MS score in elderly adults living in Northern Utah.Grant Funding Source: Supported by Dairy Research Institute

Effect of modifying the n‐3 and n‐6 content of the Total Western Diet on the acute inflammatory response to lipopolysaccharide in C57BL mice (40.2)

To objective of this study was to determine if physiologically relevant levels of omega‐6 (n6) and omega‐3 (n3) fatty acids in the Total Western Diet (TWD) affect the acute inflammatory response in C57 mice challenged with LPS. The TWD is a new rodent diet that was formulated to match the macronutrient and micronutrient intakes of Americans and is based on data collected in 2009‐2010 in NHANES. Thirty‐two mice were randomly assigned to one of four versions of the TWD differing in n6 and n3 content. Based on NHANES, a typical Western Diet contains 7% kcal from n6 and 0.7% kcal n3. The diets used in this 2 x 2 design reflected the 10th and 90th percentile of n6 and n3 intakes. All diets contained 34% kcal from fat with the following n6 and n3 compositions (all in kcal): HH (10.4% n6, 1.1% n3 (10:1 ratio)), HL (10.4% n6, 0.4% n3 (26:1 ratio)), LH (5.1% n6, 1.1% (5:1 ratio)) and LL (5.1% n6, 0.4% n3 (13:1)). After 28d mice were challenged with 10mg/kg of an intraperitoneal injection of lipopolysaccharide (LPS), sacrificed after 24 h and plasma and tissues were collected. Fatty acids were measured in erythrocytes using gas chromatography and plasma cytokines were measured using a multiplexed bead assay. Mice fed the HH diet gained more 29% more weight than LH diet and 39% more than those fed the LL diet. The erythrocyte fatty acid profile indicated the LH group had significant more DHA and DPA than other diet groups, and higher EPA than HL and LL groups. Arachidonic acid, on the other hand, was not different between groups. Despite the differences in PUFA intakes there were no significant difference between the groups in the pro‐inflammatory and anti‐inflammatory cytokines in plasma. According to these results, dietary n6 and n3 PUFA at intakes physiologically relevant to the US diet did not affect the acute inflammatory response to LPS.Grant Funding Source: USDA‐NIFA

Dietary zinc deficiency affects blood linoleic acid:dihomo‐γ‐linolenic acid ratio: a sensitive physiological marker of zinc status in vivo (Gallus gallus) (1043.2)

Zinc (Zn) is a vital micronutrient for over 300 enzymatic reactions and multiple biochemical and structural processes. Sensitive biological markers of Zn status are needed, especially in delineating varying stages of Zn deficiency. Our objective was to evaluate the domestic chicken (Gallus gallus) as a model to test dietary Zn deficiency and to assess the sensitivity of a potential Zn biomarker, erythrocyte linoleic acid: dihomo‐γ‐linolenic acid (LA:DGLA) ratio. Diets identical in composition except for Zn concentration were formulated and birds (n=12) were randomly separated upon hatching into two dietary groups, Zn(+) and Zn(‐) (42 and 2.5µg/g Zn, respectively). Zn intake, BW, and serum Zn were measured weekly. Blood was collected weekly for erythrocyte fatty acid analysis. After 4 wks, tissues were collected for gene expression analysis. BW, Zn intake, and serum Zn were higher in the Zn(+) vs. Zn(‐) group (P&lt;.05). Hepatic Δ6‐desaturase, TNFα, IL1β, and IL6 gene expression were higher in the Zn(+) group (P&lt;.05). The LA:DGLA ratio was significantly elevated in the Zn(‐) group compared to the Zn(+) group (22.6±0.5 and 18.5±0.5, % w/w, respectively, P&lt;.001). This study suggests erythrocyte LA:DGLA ratio is able to differentiate Zn status between subjects with varying levels of Zn deficiency, and may be a novel biomarker to assess dietary Zn manipulation in vivo.

Abstract P251: Epigenome-Wide Study of Erythrocyte Fatty Acids in the Genetics of Lipid Lowering Drugs and Diet Network

Introduction: Dietary fatty acids have a role in many physiological mechanisms that influence cardiovascular health. An emerging body of evidence suggests that dietary fats may interact with genetic variants in regulating tissue levels of fatty acids, thus impacting disease risk. Epigenetic changes such as DNA methylation are a promising mechanism underlying such interactions. However, no studies to date have investigated the relationship between DNA methylation and tissue fatty acids at the genome-wide level. Methods: We have performed the first epigenome-wide association study (EWAS) of erythrocyte concentrations of polyunsaturated, monounsaturated, saturated, and trans fatty acids in 958 participants of the Genetics of Diet and Lipid Lowering Drugs Network (GOLDN). We assayed the methylation status of approximately 450,000 CpG sites in CD4+ T-cells. To investigate the associations between methylation of each CpG site and red blood cell fatty acids, we fit linear mixed models adjusted for age, sex, cell purity, and family structure. Results: The strongest association was observed between the methylation status of a CpG site in PDE4D, previously linked to systemic inflammation and stroke, and red blood cell trans fatty acids (P=4x10-7). In the analysis of polyunsaturated fatty acids, we found inverse associations with the methylation status of two CpG sites in BRSK2 (P=9x10-6 and P=1x10-5 respectively), as well as with a CpG site located in a “gene desert” on chromosome 14 proximally to VRK1 (P=5x10-7). BRSK2 encodes a kinase previously shown to control epigenetic programs that determine T-cell function. The top hits for monounsaturated and saturated fatty acids were located in ATL2 (P=1x10-6) and FGD2 (P=1x10-5), respectively. Conclusions: We present preliminary evidence of cross-sectional association between the methylation status of several biologically relevant genomic regions and erythrocyte concentrations of polyunsaturated, trans, monounsaturated, and saturated fatty acids. Upon successful validation, these findings further current understanding of gene-fatty acid interactions in human health and disease.

Plasma and erythrocyte membrane phospholipids and fatty acids in Italian general population and hemodialysis patients

BackgroundDyslipidemia and abnormal phospholipid metabolism are frequent in uremic patients and increase their risk of cardiovascular disease (CVD): ω-3 polyunsaturated fatty acids (PUFAs) may reduce this risk in the general population. In this study we compared the plasma and erythrocyte cell membrane composition of PUFAs in a group of Caucasian hemodialysis (HD) patients and in a control group of healthy subjects and evaluated the erythrocyte/cell membrane fatty acid ratio as a marker of the dietary intake of phospholipids. The relationship between ω-3 and ω-6 fatty acids and the possible differences in PUFAs concentrations were also investigated.Methods and resultsAfter obtaining a fully informed consent, a total of ninety-nine HD patients and 160 non uremic control subjects from “Tor Vergata” University Hospital were enrolled into the study. None of them took antioxidant drugs or dietary supplements for at least 90 days prior to the observation. Blood samples were analysed by gas-chromatographic coupled to a mass spectrometric detector.The daily intake of total calories, proteins, lipids and carbohydrates is significantly lower in HD patients than in controls (p < 0.001). Most plasma and erythrocyte PUFA were also reduced significantly in HD patients (p < 0.001).ConclusionsOur results suggest that many classes of PUFAs are lacking in HD patients, due to the removal of nutrients during the dialysis and to persistent malnutrition. A dietary treatment addressed to increase plasma ω-3 PUFAs and to optimize ω-6/ω-3 ratio may exert a protective action and reduce the risk of CVD in HD patient.

Dietary Zinc Deficiency Affects Blood Linoleic Acid: Dihomo-γ-linolenic Acid (LA:DGLA) Ratio; a Sensitive Physiological Marker of Zinc Status in Vivo (Gallus gallus)

Zinc is a vital micronutrient used for over 300 enzymatic reactions and multiple biochemical and structural processes in the body. To date, sensitive and specific biological markers of zinc status are still needed. The aim of this study was to evaluate Gallus gallus as an in vivo model in the context of assessing the sensitivity of a previously unexplored potential zinc biomarker, the erythrocyte linoleic acid: dihomo-γ-linolenic acid (LA:DGLA) ratio. Diets identical in composition were formulated and two groups of birds (n = 12) were randomly separated upon hatching into two diets, Zn(+) (zinc adequate control, 42.3 μg/g zinc), and Zn(−) (zinc deficient, 2.5 μg/g zinc). Dietary zinc intake, body weight, serum zinc, and the erythrocyte fatty acid profile were measured weekly. At the conclusion of the study, tissues were collected for gene expression analysis. Body weight, feed consumption, zinc intake, and serum zinc were higher in the Zn(+) control versus Zn(−) group (p < 0.05). Hepatic TNF-α, IL-1β, and IL-6 gene expression were higher in the Zn(+) control group (p < 0.05), and hepatic Δ6 desaturase was significantly higher in the Zn(+) group (p < 0.001). The LA:DGLA ratio was significantly elevated in the Zn(−) group compared to the Zn(+) group (22.6 ± 0.5 and 18.5 ± 0.5, % w/w, respectively, p < 0.001). This study suggests erythrocyte LA:DGLA is able to differentiate zinc status between zinc adequate and zinc deficient birds, and may be a sensitive biomarker to assess dietary zinc manipulation.

Association of n-3 polyunsaturated fatty acids and inflammatory indicators with renal function decline in type 2 diabetes

The n-3 polyunsaturated fatty acids (PUFAs) and the inflammatory indicator, interleukin-6 (IL-6), have been implied in the development of renal dysfunction. This longitudinal study examined the effect of n-3 PUFAs and IL-6 on the risk of renal function decline and explored whether n-3 PUFAs modify the effect of inflammatory indicators on renal dysfunction risk in type 2 diabetes. Studying 676 type 2 diabetic patients, we analyzed erythrocyte fatty acids and inflammatory markers in 2008 and estimated glomerular filtration rate (eGFR) in 2008 and 2012. Renal function decline was defined as an eGFR decline of ≥25% over a 4-year period. Multivariable logistic regression revealed erythrocyte total PUFAs, n-3 PUFAs, and n-3/n-6 PUFA ratio correlated negatively with risk of renal function decline (OR = 0.75, 0.78, and 0.61, respectively, all p < 0.01), while n-6 PUFAs did not. IL-6 independently predicted risk of renal dysfunction (OR = 1.18, p = 0.015). Stratifying erythrocyte PUFAs into low (<50(th) percentile) or high group (≥50(th) percentile), we found a positive association between IL-6 and risk of renal dysfunction only in the low n-3 PUFA (OR = 1.27, p = 0.035), low n-3/n-6 PUFA (OR = 1.27, p = 0.034), and low total PUFA groups (OR = 1.36, p = 0.005), but not in the high groups. High PUFA concentrations, especially n-3 or higher n-3/n-6 PUFA ratio, may exert protective effects against renal function impairment in type 2 diabetic patients. Whether the effect is mediated via modification of inflammatory biomarker such as IL-6 by high n-3 PUFA status warrants further investigation.