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Concept: Polyunsaturated fatty acid

173

n-3 polyunsaturated fatty acids, namely docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), reduce the risk of cardiovascular disease and can ameliorate many of obesity-associated disorders. We hypothesised that the latter effect will be more pronounced when DHA/EPA is supplemented as phospholipids rather than as triglycerides.

Concepts: Nutrition, Fatty acid, Fatty acids, Essential fatty acid, Omega-3 fatty acid, Eicosapentaenoic acid, Docosahexaenoic acid, Polyunsaturated fatty acid

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BACKGROUND: The objective of this study was to evaluate the mediating role of maternal early pregnancy plasma levels of long chain polyunsaturated fatty acids (LCPUFAs) in the association of interpregnancy interval (IPI) with birth weight and smallness for gestational age (SGA) at birth. METHODS: We analysed a subsample of the Amsterdam Born Children and their Development (ABCD) cohort, comprising 1,659 parous pregnant women recruited between January 2003 and March 2004. We used linear and logistic regression to evaluate the associations between fatty acid status, interpregnancy interval and pregnancy outcome. RESULTS: Low plasma phospholipids concentrations of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and dihomo-gamma-linolenic acid (DGLA), and high concentrations of arachidonic acid (AA) during early pregnancy were associated with reduced birth weight and/or an increased risk of SGA. Short IPIs (< 6 months, with 18--23 months as a reference) were associated with a mean decrease of 207.6 g (SE: +/- 73.1) in birth weight (p = 0.005) and a twofold increased risk of SGA (OR: 2.05; CI: 0.93--4.51; p = 0.074). Adjustment for maternal fatty acid concentrations did not affect these results to any meaningful extent. CONCLUSIONS: Despite the observed association of maternal early pregnancy LCPUFA status with birth weight and SGA, our study provides no evidence for the existence of an important role of maternal EPA, DHA, DGLA or AA in the association of short interpregnancy intervals with birth weight and SGA.

Concepts: Fatty acid, Fatty acids, Essential fatty acid, Eicosapentaenoic acid, Omega-6 fatty acid, Linoleic acid, Arachidonic acid, Polyunsaturated fatty acid

83

Experimental evidence supports an antineoplastic activity of marine ω-3 polyunsaturated fatty acids (ω-3 PUFAs; including eicosapentaenoic acid, docosahexaenoic acid and docosapentaenoic acid). However, the influence of ω-3 PUFAs on colorectal cancer (CRC) survival is unknown.

Concepts: Nutrition, Fatty acid, Fatty acids, Essential fatty acid, Omega-3 fatty acid, Eicosapentaenoic acid, Docosahexaenoic acid, Polyunsaturated fatty acid

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Subjective memory complaints are common with aging. Docosahexaenoic acid (DHA; 22:6 n-3) is a long-chain polyunsaturated fatty acid (LCPUFA) and an integral part of neural membrane phospholipids that impacts brain structure and function. Past research demonstrates a positive association between DHA plasma status/dietary intake and cognitive function.

Concepts: Psychology, Brain, Fatty acids, Omega-3 fatty acid, Cognition, Eicosapentaenoic acid, Docosahexaenoic acid, Polyunsaturated fatty acid

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Guidelines for suggested intake of ω-3 polyunsaturated fatty acids (PUFAs) are limited in youth and rely primarily on age. However, body weight varies considerably within age classifications. The current analyses examined effects of body weight and body mass index (BMI) on fatty acid accumulation in 64 youth (7-14 years) with a diagnosed mood disorder in a double-blind randomized-controlled trial (2000mg ω-3 supplements or a control capsule) across 12 weeks. Weight and height were measured at the first study visit and EPA and DHA levels were determined using fasting blood samples obtained at both the first and end-of-study visits. In the ω-3 supplementation group, higher baseline body weight predicted less plasma accumulation of both EPA [B = -0.047, (95% CI = -0.077; -0.017), β = -0.54, p = 0.003] and DHA [B = -0.02, (95% CI = -0.034; -0.007), β = -0.52, p = 0.004]. Similarly, higher BMI percentile as well as BMI category (underweight, normal weight, overweight/obese) predicted less accumulation of EPA and DHA (ps≤0.01). Adherence to supplementation was negatively correlated with BMI percentile [B = -0.002 (95% CI = -0.004; 0.00), β = -0.44, p = 0.019], but did not meaningfully affect observed associations. As intended, the control supplement exerted no significant effect on plasma levels of relevant fatty acids regardless of youth body parameters. These data show strong linear relationships of both absolute body weight and BMI percentile with ω-3 PUFA accumulation in youth. A dose-response effect was observed across the BMI spectrum. Given increasing variability in weight within BMI percentile ranges as youth age, dosing based on absolute weight should be considered. Moreover, effects of weight should be incorporated into statistical models in studies examining clinical effects of ω-3 PUFAs in youth as well as adults, as weight-related differences in effects may contribute meaningfully to inconsistencies in the current literature.

Concepts: Nutrition, Fatty acids, Essential fatty acid, Body mass index, Eicosapentaenoic acid, Polyunsaturated fatty acid

35

Prospective observational studies have shown inconsistent associations of dietary or circulating n-3 long-chain polyunsaturated fatty acids (LCPUFA) with risk of all-cause mortality. A meta-analysis was performed to evaluate the associations. Potentially eligible studies were identified by searching PubMed and EMBASE databases. The summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated using the random-effects model. Eleven prospective studies involving 371 965 participants from general populations and 31 185 death events were included. The summary RR of all-cause mortality for high-versus-low n-3 LCPUFA intake was 0.91 (95% CI: 0.84-0.98). The summary RR for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intake was 0.83 (95% CI: 0.75-0.92) and 0.81 (95% CI: 0.74-0.95), respectively. In the dose-response analysis, each 0.3 g/d increment in n-3 LCPUFA intake was associated with 6% lower risk of all-cause mortality (RR = 0.94, 95% CI: 0.89-0.99); and each 1% increment in the proportions of circulating EPA and DHA in total fatty acids in blood was associated with 20% (RR = 0.80, 95% CI: 0.65-0.98) and 21% (RR = 0.79, 95% CI: 0.63-0.99) decreased risk of all-cause mortality, respectively. Moderate to high heterogeneity was observed across our anlayses. Our findings suggest that both dietary and circulating LCPUFA are inversely associated with all-cause mortality.

Concepts: Nutrition, Fatty acids, Essential fatty acid, Omega-3 fatty acid, Eicosapentaenoic acid, Docosahexaenoic acid, Polyunsaturated fatty acid

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Studies in rodents indicate that diets deficient in omega-3 polyunsaturated fatty acids (n-3 PUFA) lower dopamine neurotransmission as measured by striatal vesicular monoamine transporter type 2 (VMAT2) density and amphetamine-induced dopamine release. This suggests that dietary supplementation with fish oil might increase VMAT2 availability, enhance dopamine storage and release, and improve dopamine-dependent cognitive functions such as working memory. To investigate this mechanism in humans, positron emission tomography (PET) was used to measure VMAT2 availability pre- and post-supplementation of n-3 PUFA in healthy individuals. Healthy young adult subjects were scanned with PET using [(11)C]-(+)-α-dihydrotetrabenzine (DTBZ) before and after six months of n-3 PUFA supplementation (Lovaza, 2 g/day containing docosahexaenonic acid, DHA 750 mg/d and eicosapentaenoic acid, EPA 930 mg/d). In addition, subjects underwent a working memory task (n-back) and red blood cell membrane (RBC) fatty acid composition analysis pre- and post-supplementation. RBC analysis showed a significant increase in both DHA and EPA post-supplementation. In contrast, no significant change in [(11)C]DTBZ binding potential (BP(ND)) in striatum and its subdivisions were observed after supplementation with n-3 PUFA. No correlation was evident between n-3 PUFA induced change in RBC DHA or EPA levels and change in [(11)C]DTBZ BP(ND) in striatal subdivisions. However, pre-supplementation RBC DHA levels was predictive of baseline performance (i.e., adjusted hit rate, AHR on 3-back) on the n-back task (y = 0.19+0.07, r(2) = 0.55, p = 0.009). In addition, subjects AHR performance improved on 3-back post-supplementation (pre 0.65±0.27, post 0.80±0.15, p = 0.04). The correlation between n-back performance, and DHA levels are consistent with reports in which higher DHA levels is related to improved cognitive performance. However, the lack of change in [(11)C]DBTZ BP(ND) indicates that striatal VMAT2 regulation is not the mechanism of action by which n-3 PUFA improves cognitive performance.

Concepts: Nutrition, Fatty acid, Fatty acids, Essential fatty acid, Omega-3 fatty acid, Eicosapentaenoic acid, Docosahexaenoic acid, Polyunsaturated fatty acid

28

The Japanese have higher levels of n-3 polyunsaturated fatty acids (PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in their diets. These facts may contribute to the lower rates of atherosclerosis in Japanese. The purposes of this study were to assess the PUFA levels in patients with subtypes of acute ischemic stroke and to assess the relationship between severity and PUFA levels.

Concepts: Nutrition, Fatty acids, Stroke, Essential fatty acid, Omega-3 fatty acid, Eicosapentaenoic acid, Docosahexaenoic acid, Polyunsaturated fatty acid

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Microalgae are a promising feedstock for biofuels because of their capability to produce lipids. Cell disruption is necessary to maximize lipid extraction. Sonication conditions were evaluated for breaking heterotrophic (Schizochytrium limacinum) and autotrophic (Chlamydomonas reinhardtii) microalgae cells. Cell disruption was estimated by Nile red-lipids fluorescence quantification in S. limacinum and by the release of intracellular chlorophyll and carotenoids in green microalga C. reinhardtii. In both species, approximately 800J/10mL was the energy input necessary to maximize cell disruption, regardless of the cell concentrations studied. Increasing sonication time produced increasing amount of free radicals, quantified by the formation of hydroxyterephthalate. Sonication energy beyond the level needed for cell disruption induced oxidation of arachidonic acid, a polyunsaturated fatty acid typically found in marine lipids. Careful control of sonication conditions is necessary to maximize oil extraction at the lowest operational cost and to prevent oil from free radical-induced degradation.

Concepts: Fatty acid, Fatty acids, Essential fatty acid, Fat, Omega-6 fatty acid, Prostaglandin, Arachidonic acid, Polyunsaturated fatty acid

28

Background- The potential health benefits of ω-3 polyunsaturated fatty acids (PUFAs) usually are studied using a combination of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). This combination reduces vulnerability to experimentally induced atrial fibrillation (AF). It is unknown whether EPA and DHA have differential effects when taken alone. Using a model of pacing-induced atrial hemodynamic overload, we investigated the individual effects of EPA and DHA on vulnerability to AF and atrial remodeling. Methods and Results- Thirty-four dogs were randomized into 3 groups, all of which underwent simultaneous atrial and ventricular pacing at 220 beats per minute for 14 days. One group received purified DHA (≈1 g/d) orally for 21 days beginning 7 days before pacing began. Similarly, 1 group received ≈1 g/d purified EPA. In a third (control) group (No-PUFAs), 8 dogs received ≈1 g/d olive oil, and 12 were unsupplemented. Electrophysiological and echocardiographic measurements were taken at baseline and 21 days. Atrial tissue samples were collected at 21 days for histological and molecular analyses. Persistent AF inducibility was significantly reduced by DHA compared with No-PUFAs median [25-75 percentiles], 0% [0%-3%] for DHA versus 3.1% [2.2%-11%] for No-PUFAs; P=0.007) but not by EPA (3.4% [1.9%-8.9%]). DHA also reduced atrial fibrosis compared with No-PUFAs (11±6% versus 20±4%, respectively; P<0.05), whereas EPA did not (15±5%; P>0.05). Conclusions- DHA is more effective than EPA in attenuating AF vulnerability and atrial remodeling in structural remodeling-induced AF.

Concepts: Fatty acid, Fatty acids, Atrial fibrillation, Essential fatty acid, Omega-3 fatty acid, Eicosapentaenoic acid, Docosahexaenoic acid, Polyunsaturated fatty acid