790 resultados para N-3 LONG-CHAIN POLYUNSATURATED FATTY ACIDS
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Objective - The adjusted effect of long-chain polyunsaturated fatty acid (LCPUFA) intake during pregnancy on adiposity at birth of healthy full-term appropriate-for-gestational age neonates was evaluated. Study Design - In a cross-sectional convenience sample of 100 mother and infant dyads, LCPUFA intake during pregnancy was assessed by food frequency questionnaire with nutrient intake calculated using Food Processor Plus. Linear regression models for neonatal body composition measurements, assessed by air displacement plethysmography and anthropometry, were adjusted for maternal LCPUFA intakes, energy and macronutrient intakes, prepregnancy body mass index and gestational weight gain. Result - Positive associations between maternal docosahexaenoic acid intake and ponderal index in male offspring (β=0.165; 95% confidence interval (CI): 0.031–0.299; P=0.017), and between n-6:n-3 LCPUFA ratio intake and fat mass (β=0.021; 95% CI: 0.002–0.041; P=0.034) and percentage of fat mass (β=0.636; 95% CI: 0.125–1.147; P=0.016) in female offspring were found. Conclusion - Using a reliable validated method to assess body composition, adjusted positive associations between maternal docosahexaenoic acid intake and birth size in male offspring and between n-6:n-3 LCPUFA ratio intake and adiposity in female offspring were found, suggesting that maternal LCPUFA intake strongly influences fetal body composition.
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OBJECTIVE: The adjusted effect of long-chain polyunsaturated fatty acid (LCPUFA) intake during pregnancy on adiposity at birth of healthy full-term appropriate-for-gestational age neonates was evaluated. STUDY DESIGN: In a cross-sectional convenience sample of 100 mother and infant dyads, LCPUFA intake during pregnancy was assessed by food frequency questionnaire with nutrient intake calculated using Food Processor Plus. Linear regression models for neonatal body composition measurements, assessed by air displacement plethysmography and anthropometry, were adjusted for maternal LCPUFA intakes, energy and macronutrient intakes, prepregnancy body mass index and gestational weight gain. RESULT: Positive associations between maternal docosahexaenoic acid intake and ponderal index in male offspring (β=0.165; 95% confidence interval (CI): 0.031-0.299; P=0.017), and between n-6:n-3 LCPUFA ratio intake and fat mass (β=0.021; 95% CI: 0.002-0.041; P=0.034) and percentage of fat mass (β=0.636; 95% CI: 0.125-1.147; P=0.016) in female offspring were found. CONCLUSION: Using a reliable validated method to assess body composition, adjusted positive associations between maternal docosahexaenoic acid intake and birth size in male offspring and between n-6:n-3 LCPUFA ratio intake and adiposity in female offspring were found, suggesting that maternal LCPUFA intake strongly influences fetal body composition.
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Because previous studies showed that polyunsaturated fatty acids can reduce the contraction rate of spontaneously beating heart cells and have antiarrhythmic effects, we examined the effects of the fatty acids on the electrophysiology of the cardiac cycle in isolated neonatal rat cardiac myocytes. Exposure of cardiomyocytes to 10 microM eicosapentaenoic acid for 2-5 min markedly increased the strength of the depolarizing current required to elicit an action potential (from 18.0 +/- 2.4 pA to 26.8 +/- 2.7 pA, P < 0.01) and the cycle length of excitability (from 525 ms to 1225 ms, delta = 700 +/- 212, P < 0.05). These changes were due to an increase in the threshold for action potential (from -52 mV to -43 mV, delta = 9 +/- 3, P < 0.05) and a more negative resting membrane potential (from -52 mV to -57 mV, delta = 5 +/- 1, P < 0.05). There was a progressive prolongation of intervals between spontaneous action potentials and a slowed rate of phase 4 depolarization. Other polyunsaturated fatty acids--including docosahexaenoic acid, linolenic acid, linoleic acid, arachidonic acid, and its nonmetabolizable analog eicosatetraynoic acid, but neither the monounsaturated oleic acid nor the saturated stearic acid--had similar effects. The effects of the fatty acids could be reversed by washing with fatty acid-free bovine serum albumin. These results show that free polyunsaturated fatty acids can reduce membrane electrical excitability of heart cells and provide an electrophysiological basis for the antiarrhythmic effects of these fatty acids.
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Purpose It has been shown that lutein and zeaxanthin accumulate in the macula where they enhance contrast sensitivity and may reduce the risk of progression to advanced age-related macular degeneration (AMD). Furthermore, omega-3 long-chain polyunsaturated fatty acids (PUFA) might further reduce this risk. However, controversy exists regarding whether PUFA may reduce the bioavailability of lutein. Methods This was a prospective 12-month, randomized, open label study evaluating the effect of supplementation with lutein, other antioxidants, and minerals on contrast sensitivity (CS) and macular pigment optical density (MPOD) in patients with age-related maculopathy. A total of 79 patients were randomized to either lutein (10 mg) and antioxidant supplement or lutein and antioxidant supplement in combination with PUFA. Patients received supplementation for a period of 6 months and were followed for a total of 12 months. Results Serum lutein and zeaxanthin increased significantly by the first follow-up visit at 1 month, and remained elevated throughout the intervention period of 6 months in the lutein-only group but not in the lutein+PUFA group. Macular pigment optical density and CS increased significantly in the lutein-only group (P < 0.005) but not in the lutein+PUFA group (P = 0.059) compared to baseline. Best-corrected visual acuity remained unchanged during the entire study period in both groups. Conclusions Addition of PUFA may reduce the bioavailability of lutein and therefore lessen the beneficial effect on macular pigment and CS. This needs to be considered when prescribing lutein supplements to patients with low lutein levels. (ClinicalTrials.gov number, NCT00563979.).
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Recent evidence indicates that long-chain polyunsaturated fatty acids (PUFAs) can prevent cardiac arrhythmias by a reduction of cardiomyocyte excitability. This was shown to be due to a modulation of the voltage-dependent inactivation of both sodium (INa) and calcium (ICa) currents. To establish whether PUFAs also regulate neuronal excitability, the effects of PUFAs on INa and ICa were assessed in CA1 neurons freshly isolated from the rat hippocampus. Extracellular application of PUFAs produced a concentration-dependent shift of the voltage dependence of inactivation of both INa and ICa to more hyperpolarized potentials. Consequently, they accelerated the inactivation and retarded the recovery from inactivation. The EC50 for the shift of the INa steady-state inactivation curve was 2.1 +/- 0.4 microM for docosahexaenoic acid (DHA) and 4 +/- 0.4 microM for eicosapentaenoic acid (EPA). The EC50 for the shift on the ICa inactivation curve was 2.1 +/- 0.4 for DHA and > 15 microM for EPA. Additionally, DHA and EPA suppressed both INa and ICa amplitude at concentrations > 10 microM. PUFAs did not affect the voltage dependence of activation. The monounsaturated oleic acid and the saturated palmitic acid were virtually ineffective. The combined effects of the PUFAs on INa and ICa may reduce neuronal excitability and may exert anticonvulsive effects in vivo.
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Background Dietary lipids are directly related to the composition of adipose tissue, aetiology of obesity and arousal of obesity-related pathologies, like chronic inflammation states. Haptoglobin is an acute phase protein secreted by the liver and white adipose tissue, and its blood levels vary according to the volume of fat in the body. Aim of the study To investigate the effect of diets enriched with large amounts of dietary fats, which differ in their fatty acid composition, on the haptoglobin gene expression by visceral and subcutaneous adipose tissue of mice fed for 2 days or 8 weeks. 3T3-L1 cells were treated with fatty acids that are found in those types of dietary fats. Methods Mice were treated acutely (for 2 days) or chronically (for 8 weeks) with diets enriched with soybean oil, fish oil, coconut oil or lard. 3T3-L1 cells were treated with six different fatty acids. Haptoglobin gene expression was quantified by northern blotting. Results Both chronic and acute treatment with lard, which is rich in long chain saturated fatty acids, increased the haptoglobin mRNA expression in the retroperitoneal and epidydimal white adipose tissues. Chronic treatment with coconut oil, which is rich in medium chain saturated fatty acids, increased the haptoglobin expression in the epidydimal and subcutaneous depots. In 3T3-L1, palmitic acid increased the haptoglobin gene expression. Conclusion The type of lipids in the diet can differently modulate the white adipose tissue gene expression of haptoglobin, and saturated fatty acids play a major role in promoting a pro-inflammatory environment. This response is fat pad specific and dependant on the duration of treatment.
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Microspore-derived embryos of Brassica napus cv Reston were used to examine the effects of exogenous (+)-abscisic acid (ABA) and related compounds on the accumulation of very-long-chain monounsaturated fatty acids (VLCMFAs), VLCMFA elongase complex activity, and induction of the 3-ketoacyl-coenzyme A synthase (KCS) gene encoding the condensing enzyme of the VLCMFA elongation system. Of the concentrations tested, (+)-ABA at 10 μm showed the strongest effect. Maximum activity of the elongase complex, observed 6 h after 10 μm (+)-ABA treatment, was 60% higher than that of the untreated embryos at 24 h. The transcript of the KCS gene was induced by 10 μm (+)-ABA within 1 h and further increased up to 6 h. The VLCMFAs eicosenoic acid (20:1) and erucoic acid (22:1) increased by 1.5- to 2-fold in embryos treated with (+)-ABA for 72 h. Also, (+)-8′-methylene ABA, which is metabolized more slowly than ABA, had a stronger ABA-like effect on the KCS gene transcription, elongase complex activity (28% higher), and level of VLCMFAs (25–30% higher) than ABA. After 24 h approximately 60% of the added (+)-[3H]ABA (10 μm) was metabolized, yielding labeled phaseic and dihydrophaseic acid. This study demonstrates that (+)-ABA promotes VLCMFA biosynthesis via increased expression of the KCS gene and that reducing ABA catabolism would increase VLCMFAs in microspore-derived embryos.
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A number of research studies have reported abnormal plasma fatty acid profiles in children with ADHD along with some benefit of n−3 to symptoms of ADHD. However, it is currently unclear whether (lower) long chain-polyunsaturated fatty acids (LC-PUFAs) are related to ADHD pathology or to associated behaviours. The aim of this study was to test whether (1) ADHD children have abnormal plasma LC-PUFA levels and (2) ADHD symptoms and associated behaviours are correlated with LC-PUFA levels. Seventy-two, male children with (n=29) and without a clinical diagnosis of ADHD (n=43) were compared in their plasma levels of LC-PUFA. Plasma DHA was higher in the control group prior to statistical correction. Callous–unemotional (CU) traits were found to be significantly negatively related to both eicosapentaenoic acid (EPA), and total omega-3 in the ADHD group. The findings unveil for the first time that CU and anti-social traits in ADHD are associated with lower omega-3 levels.
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Tese de Doutoramento em Ciências Veterinárias, especialidade de Produção Animal
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The aim of this study was to determine and compare the fatty acid (FA) composition of colostrum and mature milk produced by nursing mothers of preterm and at-term newborns, in Florianopolis, SC, Brazil. Low contents of Eicosapentaenoic acid (EPA) (0.02%/colostrum and 0.01%/mature milk for preterm and term milk) and Docosahexaenoic acid (DHA) (colostrum group: 0.10%/preterm and 0.09%/term; mature milk: 0.05%/preterm and 0.03%/term) were determined. The comparison among the groups showed that the elaidic acid content was significantly higher (1.67%) in mature term milk. The content of rumenic acid (conjugated linoleic acid) was significantly higher in at-term colostrum compared with preterm colostrum. When considering the maturity of the milk, there was a significant increase in the percentage of this FA in the preterm group. The results show that, overall, the greatest differences observed were between the colostrums and mature milks for both groups and not between preterm and at-term mothers.
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Objective - The study evaluated the effect of a canned sardine supplement in C-reactive protein (CRP) in patients on hemodialysis (HD) and the compliance and adherence to this supplement. Design - This was a quasi-experimental study: Participants with a serum CRP of 5 mg/dL or less volunteered to consume a sardine supplement or were maintained on the usual cheese/ham sandwich supplement. Setting - The study took place in two outpatient dialysis units in Lisbon, Portugal. Patients - The study comprised 63 patients receiving maintenance HD three times per week for at least 6 months and an initial CRP concentration of 5 mg/dL or less. Exclusion criteria included the presence of graft vascular access or history of cancer. Intervention - After a 4-week washout period, the nutritional intervention included a canned sardine sandwich for the case group (n = 31) and a cheese or ham sandwich for the control group (n = 32), to be ingested during each routine HD session, 3 times per week, for 8 weeks. Main outcome measure - Serum levels of high-sensitivity CRP were the outcome measure. Results - Only 65 patients from the invited 186 patients met the inclusion criteria and agreed to eat the sardine sandwich supplement three times per week and were involved in the study. A significant proportion of 48% (n = 31, case group) consumed the sardine sandwich supplement three times per week for 8 weeks, fulfilling the requirements and completing the study. The present investigation showed that a sardine sandwich supplement had no effect on CRP levels among patients on HD. However, when participants were stratified according to tertiles of CRP distribution values at baseline, a reduction in CRP levels was found for those in the higher tertile, being higher for the case group (P = .047). Although diabetic patients were excluded from the analysis (eight in the sardine supplementation group and seven in the control group) a significant CRP reduction was found (P = .034). Conclusion - Although a supplement of low-dose n-3 long-chain polyunsaturated fatty acids had no effect on the plasma high-sensitivity CRP of the supplemented group, a reduction in CRP levels was found when patients were stratified for tertiles of CRP (for the upper tertile) and diabetic status (for nondiabetic patients). These findings need to be further confirmed. This canned sardine supplement was accepted by an important proportion of patients, enhancing diet variety and contributing for a greater n-3 long-chain polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid intake.
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Recently published data concerning dietary intake of fat and food sources of (n-3) long-chain polyunsaturated fatty acids (LCPUFA) in Brazil are reviewed together with data on biochemical indices of PUFA status during pregnancy and lactation and PUFA composition of breast milk in Brazilian adolescents and adults. Potential inadequacies of docosahexaenoic acid (DHA) status among Brazilian pregnant and lactating women have not yet been thoroughly evaluated. The data reviewed show that dietary intake of food sources of n-3 LCPUFA is low and possibly deficient in Brazil, and that biochemical indices of maternal DHA status and breast milk DHA content are low compared to the international literature. These data indicate inadequate DHA status among Brazilian women during pregnancy and lactation, but this evidence needs confirmation through comprehensive and specific population-based studies.
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OBJECTIVE We investigated the association between the proportion of long-chain n-3 polyunsaturated fatty acids (PUFA) in plasma phospholipids from blood samples drawn at enrollment and subsequent change in body weight. Sex, age, and BMI were considered as potential effect modifiers. METHOD A total of 1,998 women and men participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) were followed for a median of 4.9 years. The associations between the proportion of plasma phospholipid long-chain n-3 PUFA and change in weight were investigated using mixed-effect linear regression. RESULTS The proportion of long-chain n-3 PUFA was not associated with change in weight. Among all participants, the 1-year weight change was -0.7 g per 1% point higher long-chain n-3 PUFA level (95% confidence interval: -20.7 to 19.3). The results when stratified by sex, age, or BMI groups were not systematically different. CONCLUSION The results of this study suggest that the proportion of long-chain n-3 PUFA in plasma phospholipids is not associated with subsequent change in body weight within the range of exposure in the general population.
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The very long chain (VLC) n-3 polyunsaturated fatty acids (PUFA), particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are widely recognised to have beneficial effects on human health. However, recommended intakes of VLC n-3 PUFA (450 mg/day) are not being met by the diet in the majority of the population mainly because of low consumption of oil-rich fish. Current mean intake of VLC n-3 PUFA by adults is estimated to be about 282 mg/day with EPA and DHA contributing about 244 mg/day. Furthermore, the fact that only about 27% of adults eat any oil-rich fish (excluding canned tuna) and knowledge of the poor conversion of α-linolenic acid to EPA and DHA in vivo, particularly in men, leads to the need to review current dietary sources of these fatty acids. Animal-derived foods are likely to have an important function in increasing intake and studies have shown that feeding fish oils to animals can increase the EPA and DHA content of the resulting food products. This paper highlights the importance of examining current and projected consumption trends of meat and other animal products when exploring the potential impact of enriched foods by means of altering animal diets. When related to current food consumption data, potential dietary intakes of EPA+DHA from foods derived from animals fed enriched diets are calculated to be about 231 mg/day. If widely consumed, such foods could have a significant impact on progression of conditions such as cardiovascular disease. Consideration is also given to the sources of VLC n-3 PUFA in animal diets, with the sustainability of fish oil being questioned and the need to investigate the use of alternative dietary sources such as those of algal origin.
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Background: Indian Asians in Western countries have a higher rate of coronary artery disease than do the indigenous white populations, and this higher rate may be influenced by a dietary imbalance of n-6 and n-3 polyunsaturated fatty acids (PUFAs). Objective: The objective of the study was to test the hypothesis that a high background dietary intake of n-6 PUFA attenuates the effects of fish-oil supplementation on insulin sensitivity and associated blood lipids of the metabolic syndrome. Design: Twenty-nine Indian Asian men were recruited to participate in a 12-wk dietary intervention trial. Volunteers were randomly assigned to receive either a moderate or a high n-6 PUFA diet featuring modified oils and spreads over a 6-wk period. After this 6-wk period, both groups were supplemented with 4.0 g fish oil/d (2.5 g eicosapentaenoic acid + docosahexaenoic acid) for an additional 6 wk in combination with the dietary treatment. Volunteers participated in a postprandial study and an insulin sensitivity test after the 6-wk dietary intervention and again after the fish-oil supplementation period. Results: There was no significant time X treatment interaction for blood lipids or insulin action after dietary intervention with the moderate or high n-6 PUFA diets in combination with fish oil. After the 6-wk period of fish oil supplementation, fasting and postprandial plasma triacylglycerol concentrations decreased significantly. Conclusion: The background dietary n-6 PUFA concentration did not modulate the effect of fish-oil supplementation on blood lipids or measures of insulin sensitivity in this ethnic group.