Omega-3 fatty acids and hypertension in humans

Eating more sardines instead of fish oil supplementation: Beyond omega-3 polyunsaturated fatty acids, a matrix of nutrients with cardiovascular benefits

Omega-3 polyunsaturated fatty acids (n-3 PUFA) play a significant role in the prevention and management of cardiometabolic diseases associated with a mild chronic pro-inflammatory background, including type 2 diabetes, hypertension, hypertriglyceridaemia, and fatty liver disease. The effects of n-3 PUFA supplements specifically, remain controversial regarding reducing risks of cardiovascular events. n-3 PUFA supplements come at a cost for the consumer and can result in polypharmacy for patients on pharmacotherapy. Sardines are a well-known, inexpensive source of n-3 PUFA and their consumption could reduce the need for n-3 PUFA supplementation. Moreover, sardines contain other cardioprotective nutrients, although further insights are crucial to translate a recommendation for sardine consumption into clinical practice. The present review discusses the matrix of nutrients contained in sardines which confer health benefits for cardiometabolism, beyond n-3 PUFA. Sardines contain calcium, potassium, magnesium, zinc, iron, taurine, arginine and other nutrients which together modulate mild inflammation and exacerbated oxidative stress observed in cardiovascular disease and in haemodynamic dysfunction. In a common serving of sardines, calcium, potassium, and magnesium are the minerals at higher amounts to elicit clinical benefits, whilst other nutrients are present in lower but valuable amounts. A pragmatic approach towards the consumption of such nutrients in the clinical scenario should be adopted to consider the dose-response relationship effects on physiological interactions. As most recommendations currently available are based on an indirect rationale of the physiological actions of the nutrients found in sardines, randomised clinical trials are warranted to expand the evidence on the benefits of sardine consumption.

Dietary Fats and Cardio-Metabolic Outcomes in a Cohort of Italian Adults

Background: Dietary fats, and especially saturated fatty acid (SFA), have been blamed for being the culprit in the dramatic increase in obesity and its associated diseases. However multiple systematic reviews and recent meta-analyses do not support the association between SFA and cardiovascular diseases. Thus, the objective of this study was to test whether specific types and subtypes of dietary fats are associated with metabolic outcomes in a cohort of Italian adults. Methods: Nutritional and demographic data of 1936 adults living in the south of Italy were examined. Food frequency questionnaires (FFQs) were administered to assess the intake of total dietary fat and each specific class of dietary fat, such as SFA, monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA). The intake of fatty acids was also examined according to the carbon-chain length of each individual class. Cases of hypertension, type-2 diabetes and dyslipidemias were collected from previous doctor-confirmed diagnosis records (or direct measurement of blood pressure). Results: After adjustment for potential confounding factors, individuals reporting higher intakes of total and saturated fats were associated with lower likelihood of having hypertension (odds ratio (OR) = 0.57, 95% CI: 0.35, 0.91 and OR = 0.55, 95% CI: 0.34, 0.89, respectively). Moreover, higher intake of short-chain saturated fatty acids (SCSFAs) and medium-chain saturated fatty acids (MCSFAs) was inversely associated with dyslipidemia and diabetes (OR = 0.43, 95% CI: 0.23, 0.82 and OR = 0.25, 95% CI: 0.09, 0.72, respectively). Among MUFAs, C18:1 was inversely associated with hypertension and diabetes (OR = 0.52, 95% CI: 0.30, 0.92 and OR = 0.21, 95% CI: 0.07, 0.67, respectively), while C14:1 intake was inversely associated only with hypertension (OR = 0.57, 95% CI: 0.37, 0.88). In contrast, C20:1 intake was associated with dyslipidemia (OR = 3.35, 95% CI: 1.33, 8.42). Regarding PUFA, C18:2 and 20:5 were inversely associated with hypertension (OR = 0.33, 95% CI: 0.18, 0.60 and OR = 0.30, 95% CI: 0.10, 0.89, respectively). Conclusions: The consumption of SFA does not seem to be harmful to cardio-metabolic health and, on the contrary, SCSFA may exert beneficial effects. Further studies are needed to clearly validate the results of the present study.

Unexpected Antioxidant Efficiency of Chlorogenic Acid Phenolipids in Fish Oil-in-Water Nanoemulsions: An Example of How Relatively Low Interfacial Concentrations Can Make Antioxidants to Be Inefficient

Selecting effective antioxidants is challenging since their efficiency in inhibiting lipid oxidation depends on the rate constants of the chemical reactions involved and their concentration at the reaction site, i.e., at the interfacial region. Accumulation of antioxidants at the interface of emulsions is key to modulate their efficiency in inhibiting lipid oxidation but its control was not well understood, especially in emulsions. It can be optimized by modifying the physicochemical properties of antioxidants or the environmental conditions. In this work, we analyze the effects of surfactant concentration, droplet size, and oil to water ratio on the effective interfacial concentration of a set of chlorogenic acid (CGA) esters in fish oil-in-water (O/W) emulsions and nanoemulsions and on their antioxidant efficiency. A well-established pseudophase kinetic model is used to determine in the intact emulsified systems the effective concentrations of the antioxidants (AOs). The relative oxidative stability of the emulsions is assessed by monitoring the formation of primary oxidation products with time. Results show that the concentration of all AOs at the interfacial region is much higher (20–90 fold) than the stoichiometric one but is much lower than those of other phenolipid series such as caffeic or hydroxytyrosol derivatives. The main parameter controlling the interfacial concentration of antioxidants is the surfactant volume fraction, Φ_I, followed by the O/W ratio. Changes in the droplet sizes (emulsions and nanoemulsions) have no influence on the interfacial concentrations. Despite the high radical scavenging capacity of CGA derivatives and their being concentrated at the interfacial region, the investigated AOs do not show a significant effect in inhibiting lipid oxidation in contrast with what is observed using other series of homologous antioxidants with similar reactivity. Results are tentatively interpreted in terms of the relatively low interfacial concentrations of the antioxidants, which may not be high enough to make the rate of the inhibition reaction faster than the rate of radical propagation.

Omega-3 supplementation during unilateral resistance exercise training in older women: A within subject and double-blind placebo-controlled trial

Background & aims

The skeletal muscle anabolic effects of n-3 polyunsaturated fatty acids (n-3 PUFA) appear favoured towards women; a property that could be exploited in older women who typically exhibit poor muscle growth responses to resistance exercise training (RET). Here we sought to generate novel insights into the efficacy and mechanisms of n-3 PUFA alongside short-term RET in older women.

Methods

We recruited 16 healthy older women (Placebo n = 8 (PLA): 67±1y, n-3 PUFA n = 8: 64±1y) to a randomised double-blind placebo-controlled trial (n-3 PUFA; 3680 mg/day versus PLA) of 6 weeks fully-supervised progressive unilateral RET (i.e. 6 × 8 reps, 75% 1-RM, 3/wk⁻¹). Strength was assessed by knee extensor 1-RM and isokinetic dynamometry ∼ every 10 d. Thigh fat free mass (TFFM) was measured by DXA at 0/3/6 weeks. Bilateral vastus lateralis (VL) biopsies at 0/2/4/6 weeks with deuterium oxide (D₂O) dosing were used to determine MPS responses for 0–2 and 4–6 weeks. Further, fibre cross sectional area (CSA), myonuclei number and satellite cell (SC) number were assessed, alongside muscle anabolic/catabolic signalling via immunoblotting.

Results

RET increased 1-RM equally in the trained leg of both groups (+23 ± 5% n-3 PUFA vs. +25 ± 5% PLA (both P < 0.01)) with no significant increase in maximum voluntary contraction (MVC) (+10 ± 6% n-3 PUFA vs. +13 ± 5% PLA). Only the n-3 PUFA group increased TFFM (3774 ± 158 g to 3961 ± 151 g n-3 PUFA (P < 0.05) vs. 3406 ± 201 g to 3561 ± 170 PLA) and type II fibre CSA (3097 ± 339 μm² to 4329 ± 264 μm² n-3 PUFA (P < 0.05) vs. 2520 ± 316 μm² to 3467 ± 303 μm² in PL) with RET. Myonuclei number increased equally in n-3 PUFA and PLA in both type I and type II fibres, with no change in SC number. N-3 PUFA had no added benefit on muscle protein synthesis (MPS), however, during weeks 4–6 of RET, absolute synthesis rates (ASR) displayed a trend to increase with n-3 PUFA only (5.6 ± 0.3 g d⁻¹ to 7.1 ± 0.5 g d⁻¹ n-3 PUFA (P = 0.09) vs. 5.5 ± 0.5 g d⁻¹ to 6.5 ± 0.5 g d⁻¹ PLA). Further, the n-3 PUFA group displayed greater 4EBP1 activation after acute RE at 6 weeks.

Conclusion

n3-PUFA enhanced RET gains in muscle mass through type II fibre hypertrophy, with data suggesting a role for MPS rather than via SC recruitment. As such, the present study adds to a literature base illustrating the apparent enhancement of muscle hypertrophy with RET in older women fed adjuvant n3-PUFA.

Interfacial Concentrations of Hydroxytyrosol Derivatives in Fish Oil-in-Water Emulsions and Nanoemulsions and Its Influence on Their Lipid Oxidation: Droplet Size Effects

Reports on the effect of droplet size on the oxidative stability of emulsions and nanoemulsions are scarce in the literature and frequently contradictory. Here, we have employed a set of hydroxytyrosol (HT) esters of different hydrophobicity and fish oil-in-water emulsified systems containing droplets of different sizes to evaluate the effect of the droplet size, surfactant, (Φ_I) and oil (Φ_O) volume fractions on their oxidative stability. To quantitatively unravel the observed findings, we employed a well-established pseudophase kinetic model to determine the distribution and interfacial concentrations of the antioxidants (AOs) in the intact emulsions and nanoemulsions. Results show that there is a direct correlation between antioxidant efficiency and the concentration of the AOs in the interfacial region, which is much higher (20–200 fold) than the stoichiometric one. In both emulsified systems, the highest interfacial concentration and the highest antioxidant efficiency was found for hydroxytyrosol octanoate. Results clearly show that the principal parameter controlling the partitioning of antioxidants is the surfactant volume fraction, Φ_I, followed by the O/W ratio; meanwhile, the droplet size has no influence on their interfacial concentrations and, therefore, on their antioxidant efficiency. Moreover, no correlation was seen between droplet size and oxidative stability of both emulsions and nanoemulsions.

The effects of Canola oil on cardiovascular risk factors: A systematic review and meta-analysis with dose-response analysis of controlled clinical trials

BACKGROUND AND AIMS

Canola oil (CO) is a plant-based oil with the potential to improve several cardiometabolic risk factors. We systematically reviewed controlled clinical trials investigating the effects of CO on lipid profiles, apo-lipoproteins, glycemic indices, inflammation, and blood pressure compared to other edible oils in adults.

METHODS AND RESULTS

Online databases were searched for articles up to January 2020. Forty-two articles met the inclusion criteria. CO significantly reduced total cholesterol (TC, -0.27 mmol/l, n = 37), low-density lipoprotein cholesterol (LDL-C, -0.23 mmol/l, n = 35), LDL-C to high-density lipoprotein cholesterol ratio (LDL/HDL, -0.21, n = 10), TC/HDL (-0.13, n = 15), apolipoprotein B (Apo B, -0.03 g/l, n = 14), and Apo B/Apo A-1 (-0.02, n = 6) compared to other edible oils (P < 0.05). Compared to olive oil, CO decreased TC (-0.23 mmol/l, n = 9), LDL-C (-0.17 mmol/l, n = 9), LDL/HDL (-0.39, n = 2), and triglycerides in VLDL (VLDL-TG, -0.10 mmol/l, n = 2) (P < 0.05). Compared to sunflower oil, CO improved LDL-C (-0.14 mmol/l, n = 11), and LDL/HDL (-0.30, n = 3) (P < 0.05). In comparison with saturated fats, CO improved TC (-0.59 mmol/l, n = 11), TG (-0.08 mmol/l, n = 11), LDL-C (-0.49 mmol/l, n = 10), TC/HDL (-0.29, n = 5), and Apo B (-0.09 g/l, n = 4) (P < 0.05). Based on the nonlinear dose-response curve, replacing CO with ~15% of total caloric intake provided the greatest benefits.

CONCLUSION

CO significantly improved different cardiometabolic risk factors compared to other edible oils. Further well-designed clinical trials are warranted to confirm the dose-response associations.

Intervention of Uncaria and Its Components on Liver Lipid Metabolism in Spontaneously Hypertensive Rats

Uncaria rhynchophylla (Miq.) Miq. ex Havil is widely used in the treatment of hypertension. The Uncaria extract and its bioactives, rhynchophylline and isorhynchophylline, reduced the blood pressure and fatty content in liver cells. In the present study, the antihypertensive effects of Uncaria ethanol extract (UET), rhynchophylline (RT) and isorhynchophylline (IT) were investigated in spontaneously hypertensive rats (SHR) using UPLC-Q-Orbitrap/MS based lipidomics approach. Histological changes in the liver were evaluated. Cytolysis and fatty degeneration in the liver tissues were observed in the SHR group. Lipid species in WKY, SHR treated with UET, RT, and IT were plotted to obtain the Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) score plots. Fifty-six endogenous metabolites in the liver such as glycerides, glycerophospholipids, unsaturated fatty acids, and sphingomyelins were selected as potential hypertension associated biomarkers. In order to further explore the metabolite targets of UET for antihypertensive, student's t test and correlation analysis were performed to recognize the pattern recognition and to select the significant metabolites. Similar and prolonged reduction in blood pressure was observed in all SHR groups treated with UET, RT, and IT, while the metabolite profiles were perturbed slightly compared to that of the untreated SHR. Further analysis showed that only a few common components were observed in both RT and IT, which showed similar antihypertensive effect in spite of the distinct metabolic pathways. These results help in understanding the mechanisms of isomeric ingredients in exhibiting the antihypertensive effect but with different targets.

Plasma phospholipid very-long-chain SFAs in midlife and 20-year cognitive change in the Atherosclerosis Risk in Communities (ARIC): a cohort study

BACKGROUND

Very-long-chain SFAs (VLSFAs) have recently gained considerable attention as having beneficial effects on health and aging.

OBJECTIVES

The objective of this study was to assess the associations of plasma phospholipid VLSFAs [arachidic acid (20:0), behenic acid (22:0), tricosanoic acid (23:0), and lignoceric acid (24:0)] with 20-y cognitive decline in the Atherosclerosis Risk in Communities (ARIC) participants. Furthermore, this study compared the associations of plasma phospholipid VLSFAs with 5 common groups of fatty acids [i.e., total SFAs, total MUFAs, total ω-3 (n-3) PUFAs, total marine-derived ω-3 PUFAs, total ω-6 PUFAs].

METHODS

This study used a cohort study design of 3229 ARIC participants enrolled at the Minnesota field center. Fatty acids were measured at visit 1 (1987-1989); and cognition was assessed at visits 2 (1990-1992), 4 (1996-1998), and 5 (2011-2013) using 3 tests: the Delayed Word Recall Test (DWRT), the Digit-Symbol Substitution Test (DSST), and the Word Fluency Test (WFT).

RESULTS

Higher proportions of plasma phospholipid total VLSFAs and each individual VLSFA were associated with less decline in WFT, a test of verbal fluency. For example, 1 SD higher in total VLSFAs at baseline was associated with 0.057 SD (95% CI: 0.018, 0.096, P = 0.004) less cognitive decline over 20 y as measured by WFT score. None of the 5 common fatty acid groups were associated with change in WFT, but a higher proportion of plasma phospholipid total MUFAs was associated with greater decline in DWRT; higher total ω-6 PUFAs with less decline in DWRT; and higher total ω-3 and total marine-derived ω-3 PUFAs with less decline in DSST.

CONCLUSIONS

This study suggests that higher proportions of plasma phospholipid VLSFAs in midlife may be associated with less 20-y cognitive decline.

Evidence of the Role of Omega-3 Polyunsaturated Fatty Acids in Brain Glucose Metabolism

In mammals, brain function, particularly neuronal activity, has high energy needs. When glucose is supplemented by alternative oxidative substrates under different physiological conditions, these fuels do not fully replace the functions fulfilled by glucose. Thus, it is of major importance that the brain is almost continuously supplied with glucose from the circulation. Numerous studies describe the decrease in brain glucose metabolism during healthy or pathological ageing, but little is known about the mechanisms that cause such impairment. Although it appears difficult to determine the exact role of brain glucose hypometabolism during healthy ageing or during age-related neurodegenerative diseases such as Alzheimer’s disease, uninterrupted glucose supply to the brain is still of major importance for proper brain function. Interestingly, a body of evidence suggests that dietary n-3 polyunsaturated fatty acids (PUFAs) might play significant roles in brain glucose regulation. Thus, the goal of the present review is to summarize this evidence and address the role of n-3 PUFAs in brain energy metabolism. Taken together, these data suggest that ensuring an adequate dietary supply of n-3 PUFAs could constitute an essential aspect of a promising strategy to promote optimal brain function during both healthy and pathological ageing.

Genome-Wide Association Study for Serum Omega-3 and Omega-6 Polyunsaturated Fatty Acids: Exploratory Analysis of the Sex-Specific Effects and Dietary Modulation in Mediterranean Subjects with Metabolic Syndrome

Many early studies presented beneficial effects of polyunsaturated fatty acids (PUFA) on cardiovascular risk factors and disease. However, results from recent meta-analyses indicate that this effect would be very low or nil. One of the factors that may contribute to the inconsistency of the results is that, in most studies, genetic factors have not been taken into consideration. It is known that fatty acid desaturase (FADS) gene cluster in chromosome 11 is a very important determinant of plasma PUFA, and that the prevalence of the single nucleotide polymorphisms (SNPs) varies greatly between populations and may constitute a bias in meta-analyses. Previous genome-wide association studies (GWAS) have been carried out in other populations and none of them have investigated sex and Mediterranean dietary pattern interactions at the genome-wide level. Our aims were to undertake a GWAS to discover the genes most associated with serum PUFA concentrations (omega-3, omega-6, and some fatty acids) in a scarcely studied Mediterranean population with metabolic syndrome, and to explore sex and adherence to Mediterranean diet (MedDiet) interactions at the genome-wide level. Serum PUFA were determined by NMR spectroscopy. We found strong robust associations between various SNPs in the FADS cluster and omega-3 concentrations (top-ranked in the adjusted model: FADS1-rs174547, p = 3.34 × 10-14; FADS1-rs174550, p = 5.35 × 10-14; FADS2-rs1535, p = 5.85 × 10-14; FADS1-rs174546, p = 6.72 × 10-14; FADS2-rs174546, p = 9.75 × 10-14; FADS2- rs174576, p = 1.17 × 10-13; FADS2-rs174577, p = 1.12 × 10-12, among others). We also detected a genome-wide significant association with other genes in chromosome 11: MYRF (myelin regulatory factor)-rs174535, p = 1.49 × 10-12; TMEM258 (transmembrane protein 258)-rs102275, p = 2.43 × 10-12; FEN1 (flap structure-specific endonuclease 1)-rs174538, p = 1.96 × 10-11). Similar genome-wide statistically significant results were found for docosahexaenoic fatty acid (DHA). However, no such associations were detected for omega-6 PUFAs or linoleic acid (LA). For total PUFA, we observed a consistent gene*sex interaction with the DNTTIP2 (deoxynucleotidyl transferase terminal interacting protein 2)-rs3747965 p = 1.36 × 10-8. For adherence to MedDiet, we obtained a relevant interaction with the ME1 (malic enzyme 1) gene (a gene strongly regulated by fat) in determining serum omega-3. The top-ranked SNP for this interaction was ME1-rs3798890 (p = 2.15 × 10-7). In the regional-wide association study, specifically focused on the FADS1/FASD2/FADS3 and ELOVL (fatty acid elongase) 2/ELOVL 5 regions, we detected several statistically significant associations at p < 0.05. In conclusion, our results confirm a robust role of the FADS cluster on serum PUFA in this population, but the associations vary depending on the PUFA. Moreover, the detection of some sex and diet interactions underlines the need for these associations/interactions to be studied in all specific populations so as to better understand the complex metabolism of PUFA.

Role of cytochrome P450-derived, polyunsaturated fatty acid mediators in diabetes and the metabolic syndrome

Over the last decade, cases of metabolic syndrome and type II diabetes have increased exponentially. Exercise and ω-3 polyunsaturated fatty acid (PUFA)-enriched diets are usually prescribed but no therapy is effectively able to restore the impaired glucose metabolism, hypertension, and atherogenic dyslipidemia encountered by diabetic patients. PUFAs are metabolized by different enzymes into bioactive metabolites with anti- or pro-inflammatory activity. One important class of PUFA metabolizing enzymes are the cytochrome P450 (CYP) enzymes that can generate a series of bioactive products, many of which have been attributed protective/anti-inflammatory and insulin-sensitizing effects in animal models. PUFA epoxides are, however, further metabolized by the soluble epoxide hydrolase (sEH) to fatty acid diols. The biological actions of the latter are less well understood but while low concentrations may be biologically important, higher concentrations of diols derived from linoleic acid and docosahexaenoic acid have been linked with inflammation. One potential application for sEH inhibitors is in the treatment of diabetic retinopathy where sEH expression and activity is elevated as are levels of a diol of docosahexaenoic acid that can induce the destabilization of the retina vasculature.

Effect of Low Dose Docosahexaenoic Acid-Rich Fish Oil on Plasma Lipids and Lipoproteins in Pre-Menopausal Women: A Dose⁻Response Randomized Placebo-Controlled Trial

Omega-3 long chain polyunsaturated fatty acid (n-3 LCPUFA) supplementation has been shown to improve plasma lipid profiles in men and post-menopausal women, however, data for pre-menopausal women are lacking. The benefits of intakes less than 1 g/day have not been well studied, and dose–response data is limited. The aim of this study was to determine the effect of low doses of docosahexaenoic acid (DHA)-rich tuna oil on plasma triglyceride (TG) lowering in pre-menopausal women, and investigate if low dose DHA-rich tuna oil supplementation would increase the low-density lipoprotein (LDL) and high-density lipoprotein (HDL) particle sizes. A randomized, double-blind, placebo-controlled trial was conducted, in which 53 healthy pre-menopausal women with mildly elevated plasma TG levels consumed 0, 0.35, 0.7, or 1 g/day n-3 LCPUFA as HiDHA™ tuna oil or placebo (Sunola oil) capsules for 8 weeks. Supplementation with 1 g/day n-3 LCPUFA, but not lower doses, reduced plasma TG by 23% in pre-menopausal women. This was reflected in a dose-dependent reduction in very-low-density lipoprotein (VLDL)-TG (R² = 0.20, p = 0.003). A weak dose-dependent shift in HDL (but not LDL) particle size was identified (R² = 0.05, p = 0.04). The results of this study indicate that DHA-rich n-3 LCPUFA supplementation at a dose of 1 g/day is an effective TG-lowering agent and increases HDL particle size in pre-menopausal women.

UPLC-Q-Exactive Orbitrap/MS-Based Lipidomics Approach To Characterize Lipid Extracts from Bee Pollen and Their in Vitro Anti-Inflammatory Properties

Bee pollen (BP) is collected by honeybees from flower pollen mixed with nectar and its secretions with extensive nutritional and therapeutic properties. Lipids are known to be critical contributors for the therapeutic effects of BP and vary depending on different plant sources; however, lipid profiles of BP are not available. Here, an UPLC-Q-Exactive Orbitrap/MS method was established for comprehensive lipidomics analysis of BP derived from three major nectar plants (Brassica campestris L., Camellia sinensis L., and Nelumbo nucifera Gaertn.). A total of nine lipid classes, including phosphatidylcholine (41 species), phosphatidylethanolamine (43 species), phosphatidylglycerol (9 species), phosphatidylserine (10 species), lysophosphatidylcholine (12 species), ceramide (8 species), diglyceride (27 species), triglyceride (137 species), and fatty acids (47 species), were first identified and quantified in the three BPs. In vitro anti-inflammatory activity was also discovered in the lipid extracts of three BPs, which has potential relevance to the abundance of phospholipids and unsaturated fatty acids in BP. Our comprehensive lipidomics profiling and in vitro anti-inflammatory properties of BP provide evidence for its future application.

Functional implications of maternal intake of flaxseed and its by-products during pregnancy and lactation on offspring

Purpose

The purpose of this review of the literature is to provide data about flaxseed intake during pregnancy and/or lactation and its effects in the offspring from birth to adulthood.

Design/methodology/approach

This review includes up-to-date information from evidence-based sources on flaxseed intake and its by-products, during pregnancy and lactation and its effects on male and female offspring, from post-weaning until adulthood. Topics included are effects on body mass; glycaemic metabolism; lipid profile; blood pressure and aortic structure; reproductive system and brain tissue.

Findings

The main effects of flaxseed or its by-products were observed in the cardiovascular system, where a lipid profile improvement and minor aortic remodelling were noticed, and in the cerebral development, where greater n-3 PUFA incorporation in the brain was detected.

Originality/value

The research done in this study, to understand the offspring response that were early exposed to the flaxseed components during pregnancy and lactation, may be the first step toward guiding future strategies for recommending the use of this seed during the offspring’s perinatal period.

Membrane-lipid therapy: A historical perspective of membrane-targeted therapies - From lipid bilayer structure to the pathophysiological regulation of cells

Our current understanding of membrane lipid composition, structure and functions has led to the investigation of their role in cell signaling, both in healthy and pathological cells. As a consequence, therapies based on the regulation of membrane lipid composition and structure have been recently developed. This novel field, known as Membrane Lipid Therapy, is growing and evolving rapidly, providing treatments that are now in use or that are being studied for their application to oncological disorders, Alzheimer's disease, spinal cord injury, stroke, diabetes, obesity, and neuropathic pain. This field has arisen from relevant discoveries on the behavior of membranes in recent decades, and it paves the way to adopt new approaches in modern pharmacology and nutrition. This innovative area will promote further investigation into membranes and the development of new therapies with molecules that target the cell membrane. Due to the prominent roles of membranes in the cells' physiology and the paucity of therapeutic approaches based on the regulation of the lipids they contain, it is expected that membrane lipid therapy will provide new treatments for numerous pathologies. The first on-purpose rationally designed molecule in this field, minerval, is currently being tested in clinical trials and it is expected to enter the market around 2020. However, it seems feasible that during the next few decades other membrane regulators will also be marketed for the treatment of human pathologies. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.

WITHDRAWN: Membrane-lipid therapy: A historical perspective of membrane-targeted therapies-From lipid bilayer structure to the pathophysiological regulation of cells

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.bbamem.2017.05.017. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Blood pressure-lowering effects of long chain n-3 fatty acids from meals enriched with liquid fish oil and from microencapsulated powder

BACKGROUND

Diet plays an important role in the etiology of hypertension. Blood pressure (BP)-lowering properties of long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) are promising. The aim was to investigate whether different formulations of fish oil differently affect blood pressure in community-dwelling adults. The hypothesis was that fish oil formulations would improve BP in comparison with a placebo.

METHODS

In this 4-week randomized, placebo-controlled, doubly-blinded dietary intervention study, participants (N = 99, >50 years) from the capital area of Iceland were randomized into three groups. Group 1 (n = 38) received 6 meals/week fortified with a liquid fish oil and placebo powder. Group 2 (n = 30) received conventional (unfortified) meals and microencapsulated powder. Group 3 (n = 31) was the control group which received conventional meals and placebo powder. Calculated on a weekly basis, the amount of EPA + DHA provided was 1.5 g/d. Systolic (SBP) and diastolic BP (DBP) were measured before and after the intervention period.

RESULTS

Seventy-seven subjects finished the study (77.8%). Drop-out rates were not different between groups. According to multivariate statistics, endpoint SBP was lower in Group 1 (-7.0 mmHg, p = 0.037) and in Group 2 (-7.2 mmHg, p = 0.037) as compared with Group 3. There was no significant difference in DBP between the groups.

CONCLUSION

Our study shows that LC n-3 PUFA from microencapsulated powder are equally effective to meaningfully reduce SBP as LC n-3 PUFA from meals enriched with liquid fish oil in comparison with a control group.

Personalized hypertension management in practice

The revolution occurring in genomic and personalized medicine is likely to have a significant impact on the management of hypertension. However, from the perspective of translating new knowledge into clinical practice, progress has been slow. This review article summarizes recent advances in hypertension-related diagnostics while also offering new perspective on hypertension management for the future. Such new perspectives will likely require a paradigm shift toward more integrated and holistic approaches for better prevention and treatment of hypertension in both individuals and the population as a whole.

Membrane lipid therapy: Modulation of the cell membrane composition and structure as a molecular base for drug discovery and new disease treatment

Nowadays we understand cell membranes not as a simple double lipid layer but as a collection of complex and dynamic protein-lipid structures and microdomains that serve as functional platforms for interacting signaling lipids and proteins. Membrane lipids and lipid structures participate directly as messengers or regulators of signal transduction. In addition, protein-lipid interactions participate in the localization of signaling protein partners to specific membrane microdomains. Thus, lipid alterations change cell signaling that are associated with a variety of diseases including cancer, obesity, neurodegenerative disorders, cardiovascular pathologies, etc. This article reviews the newly emerging field of membrane lipid therapy which involves the pharmacological regulation of membrane lipid composition and structure for the treatment of diseases. Membrane lipid therapy proposes the use of new molecules specifically designed to modify membrane lipid structures and microdomains as pharmaceutical disease-modifying agents by reversing the malfunction or altering the expression of disease-specific protein or lipid signal cascades. Here, we provide an in-depth analysis of this emerging field, especially its molecular bases and its relevance to the development of innovative therapeutic approaches.

Dietary supplementation with docosahexanoic acid (DHA) increases red blood cell membrane flexibility in mice with sickle cell disease

Humans and mice with sickle cell disease (SCD) have rigid red blood cells (RBCs). Omega-3 fatty acids, such as docosahexanoic acid (DHA), may influence RBC deformability via incorporation into the RBC membrane. In this study, sickle cell (SS) mice were fed natural ingredient rodent diets supplemented with 3% DHA (DHA diet) or a control diet matched in total fat (CTRL diet). After 8weeks of feeding, we examined the RBCs for: 1) stiffness, as measured by atomic force microscopy; 2) deformability, as measured by ektacytometry; and 3) percent irreversibly sickled RBCs on peripheral blood smears. Using atomic force microscopy, it is found that stiffness is increased and deformability decreased in RBCs from SS mice fed CTRL diet compared to wild-type mice. In contrast, RBCs from SS mice fed DHA diet had markedly decreased stiffness and increased deformability compared to RBCs from SS mice fed CTRL diet. Furthermore, examination of peripheral blood smears revealed less irreversibly sickled RBCs in SS mice fed DHA diet as compared to CTRL diet. In summary, our findings indicate that DHA supplementation improves RBC flexibility and reduces irreversibly sickled cells by 40% in SS mice. These results point to potential therapeutic benefits of dietary omega-3 fatty acids in SCD.

Complementary and alternative medicine: a survey of its use in pediatric cardiology

BACKGROUND

The use of complementary and alternative medicine is high among children and youth with chronic illnesses, including patients with cardiac conditions. Our goal was to assess the prevalence and patterns of such use among patients presenting to academic pediatric cardiology clinics in Canada.

METHODS

A survey instrument was developed to inquire about current or previous use of complementary and alternative medicine products and practices, including indications, beliefs, sources of information and whether this use was discussed with physicians. Between February and July 2007, the survey was administered to patients (or their parents/guardians) presenting to 2 hospital-based cardiology clinics: the Stollery Children's Hospital in Edmonton, Alberta, and the Children's Hospital of Eastern Ontario in Ottawa, Ontario.

RESULTS

At the Stollery Children's Hospital, 64.1% of the 145 respondents had used complementary and alternative medicine compared with 35.5% of the 31 respondents at the Children's Hospital of Eastern Ontario (p = 0.003). Overall, the most common products in current use were multivitamins (70.6%), vitamin C (22.1%), calcium (13.2%), unspecified "cold remedies" (11.8%) and fish oil or omega-3 fatty acids (11.8%). The most common practices in current use were massage (37.5%), faith healing (25.0%), chiropractic (20.0%), aromatherapy (15.0%) and Aboriginal healing (7.5%). Many patients (44.9%) used complementary and alternative medicine products at the same time as conventional prescription drugs. Concurrent use was discussed with physicians or pharmacists by 64.3% and 31.3% of respondents, respectively.

INTERPRETATION

Use of complementary and alternative medicine products and practices was high among patients seen in the pediatric cardiology clinics in our study. Most respondents believed that the use of these products and practices was helpful; few reported harms and many did not discuss this use with their physicians, increasing the potential for interactions with prescribed medications.

A new, microalgal DHA- and EPA-containing oil lowers triacylglycerols in adults with mild-to-moderate hypertriglyceridemia

In this double-blind, parallel trial, 93 healthy adults with hypertriglyceridemia (triacylglycerols [TAG] 150-499 mg/dL) were randomized to receive either a nutritional oil derived from marine algae (DHA-O; 2.4 g/day docosahexaenoic acid [DHA] and eicosapentaenoic acid [EPA] in a 2.7:1 ratio), fish oil (FO; 2.0 g/day DHA and EPA in a 0.7:1 ratio), or a corn oil/soy oil control as 4-1g softgel capsules/day with meals for 14 weeks; and were instructed to maintain their habitual diet. Percent changes from baseline for DHA-O, FO, and control, respectively, were TAG (-18.9, -22.9, 3.5; p<0.001 DHA-O and FO vs. control), low-density lipoprotein cholesterol (4.6, 6.8, -0.6; p<0.05 DHA-O and FO vs. control), and high-density lipoprotein cholesterol (4.3, 6.9, 0.6; p<0.05 FO vs. control). This study demonstrated that ingestion of microalgal DHA-O providing 2.4 g/day DHA+EPA lowered TAG levels to a degree that was not different from that of a standard fish oil product, and that was significantly more than for a corn oil/soy oil control.

Recent advances in pharmacotherapy for hypertriglyceridemia

Elevated plasma triglyceride (TG) concentrations are associated with an increased risk of atherosclerotic cardiovascular disease (CVD), hepatic steatosis and pancreatitis. Existing pharmacotherapies, such as fibrates, n-3 polyunsaturated fatty acids (PUFAs) and niacin, are partially efficacious in correcting elevated plasma TG. However, several new TG-lowering agents are in development that can regulate the transport of triglyceride-rich lipoproteins (TRLs) by modulating key enzymes, receptors or ligands involved in their metabolism. Balanced dual peroxisome proliferator-activated receptor (PPAR) α/γ agonists, inhibitors of microsomal triglyceride transfer protein (MTTP) and acyl-CoA:diacylglycerol acyltransferase-1 (DGAT-1), incretin mimetics, and apolipoprotein (apo) B-targeted antisense oligonucleotides (ASOs) can all decrease the production and secretion of TRLs; inhibitors of cholesteryl ester transfer protein (CETP) and angiopoietin-like proteins (ANGPTLs) 3 and 4, monoclonal antibodies (Mabs) against proprotein convertase subtilisin/kexin type 9 (PCSK9), apoC-III-targeted ASOs, selective peroxisome proliferator-activated receptor modulators (SPPARMs), and lipoprotein lipase (LPL) gene replacement therapy (alipogene tiparvovec) enhance the catabolism and clearance of TRLs; dual PPAR-α/δ agonists and n-3 polyunsaturated fatty acids can lower plasma TG by regulating both TRL secretion and catabolism. Varying degrees of TG reduction have been reported with the use of these therapies, and for some agents such as CETP inhibitors and PCSK9 Mabs findings have not been consistent. Whether they reduce CVD events has not been established. Trials investigating the effect of CETP inhibitors (anacetrapib and evacetrapib) and PCSK9 Mabs (AMG-145 and REGN727/SAR236553) on CVD outcomes are currently in progress, although these agents also regulate LDL metabolism and, in the case of CETP inhibitors, HDL metabolism. Further to CVD risk reduction, these new treatments might also have a potential role in the management of diabetes and non-alcoholic fatty liver disease owing to their insulin-sensitizing action (PPAR-α/γ agonists) and potential capacity to decrease hepatic TG accumulation (PPAR-α/δ agonists and DGAT-1 inhibitors), but this needs to be tested in future trials. We summarize the clinical trial findings regarding the efficacy and safety of these novel therapies for hypertriglyceridemia.

DHA-enriched high-oleic acid canola oil improves lipid profile and lowers predicted cardiovascular disease risk in the canola oil multicenter randomized controlled trial

BACKGROUND

It is well recognized that amounts of trans and saturated fats should be minimized in Western diets; however, considerable debate remains regarding optimal amounts of dietary n-9, n-6, and n-3 fatty acids.

OBJECTIVE

The objective was to examine the effects of varying n-9, n-6, and longer-chain n-3 fatty acid composition on markers of coronary heart disease (CHD) risk.

DESIGN

A randomized, double-blind, 5-period, crossover design was used. Each 4-wk treatment period was separated by 4-wk washout intervals. Volunteers with abdominal obesity consumed each of 5 identical weight-maintaining, fixed-composition diets with one of the following treatment oils (60 g/3000 kcal) in beverages: 1) conventional canola oil (Canola; n-9 rich), 2) high-oleic acid canola oil with docosahexaenoic acid (CanolaDHA; n-9 and n-3 rich), 3) a blend of corn and safflower oil (25:75) (CornSaff; n-6 rich), 4) a blend of flax and safflower oils (60:40) (FlaxSaff; n-6 and short-chain n-3 rich), or 5) high-oleic acid canola oil (CanolaOleic; highest in n-9).

RESULTS

One hundred thirty individuals completed the trial. At endpoint, total cholesterol (TC) was lowest after the FlaxSaff phase (P < 0.05 compared with Canola and CanolaDHA) and highest after the CanolaDHA phase (P < 0.05 compared with CornSaff, FlaxSaff, and CanolaOleic). Low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol were highest, and triglycerides were lowest, after CanolaDHA (P < 0.05 compared with the other diets). All diets decreased TC and LDL cholesterol from baseline to treatment endpoint (P < 0.05). CanolaDHA was the only diet that increased HDL cholesterol from baseline (3.5 ± 1.8%; P < 0.05) and produced the greatest reduction in triglycerides (-20.7 ± 3.8%; P < 0.001) and in systolic blood pressure (-3.3 ± 0.8%; P < 0.001) compared with the other diets (P < 0.05). Percentage reductions in Framingham 10-y CHD risk scores (FRS) from baseline were greatest after CanolaDHA (-19.0 ± 3.1%; P < 0.001) than after other treatments (P < 0.05).

CONCLUSION

Consumption of CanolaDHA, a novel DHA-rich canola oil, improves HDL cholesterol, triglycerides, and blood pressure, thereby reducing FRS compared with other oils varying in unsaturated fatty acid composition. This trial was registered at www.clinicaltrials.gov as NCT01351012.

An omega-3 epoxide of docosahexaenoic acid lowers blood pressure in angiotensin-II-dependent hypertension

Mediators of antihypertensive actions of docosahexaenoic acid (DHA) are largely unknown. The omega-3 epoxide of DHA, 19, 20-EDP (epoxy docosapentaenoic acid), is metabolized by soluble epoxide hydrolase (sEH), which also metabolizes the anti-inflammatory and antihypertensive arachidonic acid epoxides, epoxyeicosatrienoic acids (EETs). Based in part on plasma levels of EDPs after a DHA-rich diet, we hypothesized that 19, 20-EDP contributes to the antihypertensive actions of DHA in angiotensin-II (Ang-II)-dependent hypertension. Treatment individually with 19, 20-EDP and a potent sEH inhibitor TPPU (1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea) significantly lowered blood pressure (BP) as compared with Ang-II-infused animals. The largest reduction in BP was obtained with the combination of 19, 20-EDP and TPPU, which was more efficacious than the combination of 14, 15-EET and TPPU. Oxylipin profiling revealed that 19, 20-EDP and 14, 15-EET infusion affected not only most metabolites of the P450 pathway but also renal levels of prostaglandin-E2. Our findings suggest that 19, 20-EDP is a mediator of the antihypertensive effects of DHA in Ang-II-dependent hypertension. It seems that 19, 20-EDP requires metabolic stabilization with a sEH inhibitor to be most effective in lowering BP, although both TPPU and 19, 20-EDP are so effective on their own that demonstrating additive or synergistic interactions is difficult.

Metabolic syndrome and polycystic ovary syndrome: an intriguing overlapping

Metabolic syndrome is an increasing pathology in adults and in children, due to a parallel rise of obesity. Sedentary lifestyle, food habits, cultural influences and also a genetic predisposition can cause dyslipidemia, hypertension, abdominal obesity and insulin resistance which are the two main features of metabolic syndrome. Polycystic ovary syndrome (PCOS) is a condition directly associated with obesity, insulin resistance (HOMA index) and metabolic syndrome, and it is very interesting for its relationship and overlap with the metabolic syndrome. The relationship between the two syndromes is mutual: PCOS women have a higher prevalence of metabolic syndrome and also women with metabolic syndrome commonly present the reproductive/endocrine trait of PCOS. Prevention and treatment of metabolic syndrome and PCOS are similar for various aspects. It is necessary to treat excess adiposity and insulin resistance, with the overall goals of preventing cardiovascular disease and type 2 diabetes and improving reproductive failure in young women with PCOS. First of all, lifestyle changes, then pharmacological therapy, bariatric surgery and laparoscopic ovarian surgery represent the pillars for PCOS treatment.

The role of nutrition and nutraceutical supplements in the treatment of hypertension

Vascular biology, endothelial and vascular smooth muscle and cardiac dysfunction play a primary role in the initiation and perpetuation of hypertension, cardiovascular disease and target organ damage. Nutrient-gene interactions and epigenetics are predominant factors in promoting beneficial or detrimental effects in cardiovascular health and hypertension. Macronutrients and micronutrients can prevent, control and treat hypertension through numerous mechanisms related to vascular biology. Oxidative stress, inflammation and autoimmune dysfunction initiate and propagate hypertension and cardiovascular disease. There is a role for the selected use of single and component nutraceutical supplements, vitamins, antioxidants and minerals in the treatment of hypertension based on scientifically controlled studies which complement optimal nutrition, coupled with other lifestyle modifications.

Nutrition and nutraceutical supplements for the treatment of hypertension: part II

Vascular biology, endothelial and vascular smooth muscle, and cardiac dysfunction play a primary role in the initiation and perpetuation of hypertension, cardiovascular disease, and target organ damage. Nutrient-gene interactions and epigenetics are predominant factors in promoting beneficial or detrimental effects in cardiovascular health and hypertension. Macronutrients and micronutrients can prevent, control, and treat hypertension through numerous mechanisms related to vascular biology. Oxidative stress, inflammation, and autoimmune dysfunction initiate and propagate hypertension and cardiovascular disease. There is a role for the select use of single and component nutraceutical supplements, vitamins, antioxidants, and minerals in the treatment of hypertension based on scientifically controlled studies, which complement optimal nutrition, coupled with other lifestyle modifications.

Atherosclerosis, dyslipidemia, and inflammation: the significant role of polyunsaturated Fatty acids

Phospholipids play an essential role in cell membrane structure and function. The length and number of double bonds of fatty acids in membrane phospholipids are main determinants of fluidity, transport systems, activity of membrane-bound enzymes, and susceptibility to lipid peroxidation. The fatty acid profile of serum lipids, especially the phospholipids, reflects the fatty acid composition of cell membranes. Moreover, long-chain n-3 polyunsatured fatty acids decrease very-low-density lipoprotein assembly and secretion reducing triacylglycerol production. N-6 and n-3 polyunsatured fatty acids are the precursors of signalling molecules, termed "eicosanoids," which play an important role in the regulation of inflammation. Eicosanoids derived from n-6 polyunsatured fatty acids have proinflammatory actions, while eicosanoids derived from n-3 polyunsatured fatty acids have anti-inflammatory ones. Previous studies showed that inflammation contributes to both the onset and progression of atherosclerosis: actually, atherosclerosis is predominantly a chronic low-grade inflammatory disease of the vessel wall. Several studies suggested the relationship between long-chain n-3 polyunsaturated fatty acids and inflammation, showing that fatty acids may decrease endothelial activation and affect eicosanoid metabolism.

Effects of marine-derived omega-3 fatty acids on systemic hemodynamics at rest and during stress: a dose-response study

BACKGROUND

Omega-3 fatty acids reduced heart rate (HR) and blood pressure (BP) in some studies, but dose-response studies are rare, and little is known about underlying mechanisms.

PURPOSE

We examined effects of 0.85 g/day eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) (low dose) and 3.4 g/day EPA + DHA (high dose) on HR and systemic hemodynamics during rest, speech, and foot cold pressor tasks.

METHODS

This was a dose-response, placebo-controlled, double-blind, randomized, crossover trial (8-week treatment, 6-week washout) in 26 adults.

RESULTS

Throughout the testing sessions, HR was reduced in a dose-dependent manner. The high dose reduced BP and stroke volume and increased pre-ejection period. Reductions in BP were associated with increases in erythrocyte omega-3 fatty acids.

CONCLUSIONS

High-dose long-chain omega-3 fatty acids can reduce BP and HR, at rest and during stress. These findings suggest that at-risk populations may achieve benefits with increased omega-3 intake. The trial was registered on ClinicalTrials.gov (NCT00504309).

Dietary oils and FADS1-FADS2 genetic variants modulate [13C]α-linolenic acid metabolism and plasma fatty acid composition

BACKGROUND

Desaturation of dietary α-linolenic acid (ALA) to omega-3 (n-3) long-chain fatty acids (FAs) is mediated through FA desaturases (FADS1-FADS2) and may be influenced by dietary FA composition.

OBJECTIVE

We investigated the effects of diets enriched in flaxseed oil (FXCO) or high-oleic acid canola oil (HOCO) compared with a Western diet (WD) and FADS1-FADS2 single nucleotide polymorphisms (SNPs) on plasma FAs and [U-(13)C]ALA metabolism.

DESIGN

In a randomized crossover design, 36 hyperlipidemic subjects consumed 3 isoenergetic diets enriched in FXCO (20.6 g ALA/d), HOCO (2.4 g ALA/d), or WD (1.3 g ALA/d) for 4 wk. On day 27, blood was sampled 0, 24, and 48 h after the subjects (n = 26) consumed 45 mg [U-(13)C]ALA. The subjects were genotyped for 4 FADS SNPs.

RESULTS

FXCO increased (P < 0.001) plasma ALA, EPA, and docosapentaenoic acid (DPA), with no change in DHA compared with the HOCO or WD diets. At 24 and 48 h, [U-(13)C]ALA recovered as plasma [(13)C]EPA and [(13)C]DPA were lower (P < 0.001) after the FXCO diet than after the HOCO and WD diets. No change in [(13)C]DHA was observed between diets. Minor allele homozygotes of rs174545, rs174583, rs174561, and rs174537 had lower (P < 0.05) plasma EPA, arachidonic acid (AA), EPA/ALA, and AA/linoleic acid compositions and lower (P < 0.05) plasma [(13)C]EPA enrichment at 24 and 48 h in comparison with carriers of the major allele after all diets. SNPs were not associated with plasma composition of DHA or [(13)C]DHA enrichment.

CONCLUSION

An increase in ALA intake resulting in increased plasma EPA composition may be cardioprotective, especially in minor allele homozygotes. This trial was registered at www.clinicaltrials.gov as NCT00927199.

Sodium alginate as feed additive in cultured sea bream (Sparus aurata): does it modify the quality of the flesh?

The objective of this study was to evaluate the effect of sodium alginate obtained from brown seaweed as a prebiotic supplement to the feed of reared sea bream (Sparus aurata). Addition of the alginate to a control diet was investigated at both concentrations 2% and 5%. Proximate composition in the flesh were not modified significantly by sodium alginate inclusion in the diet of the sea bream; however the fat and ash content in the specimens supplemented with 5% alginate were found to be significantly higher than those found in individuals who were fed the control diet. No significant differences in mineral content, fatty acid profiles, cholesterol content, texture parameters and sensory acceptability among the three studied groups. Results obtained in this study offer support for the use of alginate as a feed additive in sea bream diets since no significant effects were found in the flesh quality and characteristics of commercial size sea bream.

Metabolic engineering plant seeds with fish oil-like levels of DHA

Background

Omega-3 long-chain (≥C₂₀) polyunsaturated fatty acids (ω3 LC-PUFA) have critical roles in human health and development with studies indicating that deficiencies in these fatty acids can increase the risk or severity of cardiovascular and inflammatory diseases in particular. These fatty acids are predominantly sourced from fish and algal oils, but it is widely recognised that there is an urgent need for an alternative and sustainable source of EPA and DHA. Since the earliest demonstrations of ω3 LC-PUFA engineering there has been good progress in engineering the C₂₀ EPA with seed fatty acid levels similar to that observed in bulk fish oil (∼18%), although undesirable ω6 PUFA levels have also remained high.

Methodology/Principal Findings

The transgenic seed production of the particularly important C₂₂ DHA has been problematic with many attempts resulting in the accumulation of EPA/DPA, but only a few percent of DHA. This study describes the production of up to 15% of the C₂₂ fatty acid DHA in Arabidopsis thaliana seed oil with a high ω3/ω6 ratio. This was achieved using a transgenic pathway to increase the C₁₈ ALA which was then converted to DHA by a microalgal Δ6-desaturase pathway.

Conclusions/Significance

The amount of DHA described in this study exceeds the 12% level at which DHA is generally found in bulk fish oil. This is a breakthrough in the development of sustainable alternative sources of DHA as this technology should be applicable in oilseed crops. One hectare of a Brassica napus crop containing 12% DHA in seed oil would produce as much DHA as approximately 10,000 fish.

DHA derivatives of fish oil as dietary supplements: a nutrition-based drug discovery approach for therapies to prevent metabolic cardiotoxicity

INTRODUCTION

During the early 1970s, Danish physicians Jorn Dyerberg and colleagues observed that Greenland Eskimos consuming fatty fishes exhibited low incidences of heart disease. Fish oil is now one of the most commonly consumed dietary supplements. In 2004, concentrated fish oil was approved as a drug by the FDA for the treatment of hyperlipidemia. Fish oil contains two major omega-3 fatty acids: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). With advancements in lipid concentration and purification techniques, EPA- or DHA-enriched products are now commercially available, and the availability of these components in isolation allows their individual effects to be examined. Newly synthesized derivatives and endogenously discovered metabolites of DHA exhibit therapeutic utility for obesity, metabolic syndrome and cardiovascular disease.

AREAS COVERED

This review summarizes our current knowledge on the distinct effects of EPA and DHA to prevent metabolic syndrome and reduce cardiotoxicity risk. Since EPA is an integral component of fish oil, we will briefly review EPA effects, but our main theme will be to summarize effects of the DHA derivatives that are available today. We focus on using nutrition-based drug discovery to explore the potential of DHA derivatives for the treatment of obesity, metabolic syndrome and cardiovascular diseases.

EXPERT OPINION

The safety and efficacy evaluation of DHA derivatives will provide novel biomolecules for the drug discovery arsenal. Novel nutritional-based drug discoveries of DHA derivatives or metabolites may provide realistic and alternative strategies for the treatment of metabolic and cardiovascular disease.

Associations of plasma n-3 polyunsaturated fatty acids with blood pressure and cardiovascular risk factors among Chinese

The relationship between plasma fatty acid (FA) levels and hypertension in Chinese is not fully understood. The aim of this study was to examine relationships between plasma phospholipid (PL) FAs and hypertension in Chinese subjects. One thousand one hundred and fifty-four subjects in Hangzhou, China, were recruited in this cross-sectional study. Two hundred and fourteen (160 males, 54 females) subjects with hypertension and 940 (664 males, 276 females) healthy subjects were identified. The prevalence of hypertension in females (19.6%) was significantly higher than that in males (16.4%). Compared with healthy subjects, hypertensive subjects showed significantly lower plasma PL 22:5n-3 (p = 0.017), 22:6n-3 (p = 0.008), PL polyunsaturated fatty acids (PUFAs; p < 0.001), n-3 PUFA (p = 0.015), n-6 PUFA (p < 0.001) and 20:4n-6 (p < 0.010). PL n-3 PUFA [odds ratio (OR) = 0.43, 95% confidence interval (CI) = 0.29-1.19] and n-3:n-6 (OR = 0.48, 95% CI = 0.12-1.86) were inversely associated with hypertension. However, plasma saturated fatty acid (SFA; OR = 2.01, 95% CI = 1.05-2.98) was significantly positively associated with hypertension. PL SFA was significantly positively associated with systolic blood pressure (p = 0.048), whereas plasma PL monounsaturated FA was significantly positively associated with diastolic blood pressure (DBP; p = 0.009) in hypertensive subjects. PL PUFA (p = 0.022) and n-3 PUFA (p = 0.047) were significantly negatively associated with DBP in hypertensive subjects. Our results suggest that plasma PL n-3 PUFA was significantly inversely associated with hypertension in Chinese. It would seem appropriate for hypertensive subjects to increase their dietary n-3 PUFA which may help reduce BP.

Are we consuming enough long chain omega-3 polyunsaturated fatty acids for optimal health?

The health benefits attributed to the consumption of long chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) are enormous but are we consuming enough for optimal health? Cardiovascular disease rates are much lower in countries like Japan compared with the Western world. Western countries' LC n-3 PUFA intakes are up to 5 fold lower than Japanese intakes. Various professional bodies and government organisations recommend 500mg LC n-3 PUFA per day. The actual reported intake of LC n-3 PUFA from Australia and various other countries are compared to these recommended intakes. Not surprisingly, the actual intakes of LC n-3 PUFA in Western countries fall short of the recommended intakes. Consumption of fish and seafood is the easiest way to achieve the recommended intakes but increased consumption of foods enriched with LC n-3 PUFA will also contribute to achieving the recommended intakes. Most people are not consuming enough LC n-3 PUFA for optimal health.

Fish oil, selenium and mercury in relation to incidence of hypertension: a 20-year follow-up study

OBJECTIVES

Long-chain omega-3 polyunsaturated fatty acids (LCω3PUFAs), selenium (Se) and mercury (Hg) are three important components in fish. The cardioprotective effect of LCω3PUFA intake has been recognized; however, the hypothesis that this benefit may be greatest with high Se and low Hg levels has not been investigated.

DESIGN

A cohort of 4508 American adults aged 18-30, without hypertension at baseline in 1985, were enrolled. Six follow-ups were conducted at examinations in 1987, 1990, 1992, 1995, 2000 and 2005. Diet was assessed by a validated interviewer-administered quantitative food frequency questionnaire at exams in 1985, 1992 and 2005. Incident hypertension was defined as first occurrence at any follow-up examination of systolic blood pressure (BP) ≥ 140 mmHg, diastolic BP ≥ 90 mmHg or taking antihypertensive medication. Toenail clippings were collected in 1987, and Se and Hg levels were quantified by instrumental neutron-activation analysis.

RESULT

Participants in the highest LCω3PUFA intake quartile had a significantly lower incidence of hypertension (hazard ratio: 0.65; 95% CI: 0.53-0.79; P(trend) < 0.01) compared to those in the lowest quartile after adjustment for potential confounders. Docosahexaenoic acid showed a greater inverse association than eicosapentaenoic acid. The inverse association of LCω3PUFA intake with hypertension appeared more pronounced at higher Se and lower Hg levels, although interaction tests were statistically nonsignificant.

CONCLUSIONS

Our findings indicated that LCω3PUFA intake was inversely associated with incidence of hypertension. The prior hypothesis that the potential antihypertensive effect of LCω3PUFA intake varies depending on joint levels of Se and Hg received modest support and cannot be ruled out.

Nuts, hypertension and endothelial function

BACKGROUND AND AIMS

High blood pressure (BP) is considered a major risk factor for cardiovascular disease. Among lifestyle factors, diet plays a key role in the prevention and control of high BP. Therefore, it is important to elucidate which dietary components can exert beneficial effects on BP through modulation of endothelial function (EF) or by other mechanisms. In this paper we review the role of nutrients, foods, particularly nuts, and dietary patterns on BP control.

DATA SYNTHESIS

Because nuts are low in sodium and contain significant amounts of mono- and polyunsaturated fatty acids, fiber, minerals such as magnesium, potassium and calcium, and antioxidants, they have been suggested as potentially protective foods against hypertension. Limited evidence from prospective studies and clinical trials suggests that nut consumption has a beneficial effect on both BP and EF. However, BP changes were a secondary outcome in nut feeding trials and no study used ambulatory BP monitoring as the standard for BP measurements.

CONCLUSIONS

Further clinical trials, ideally using ambulatory BP monitoring, are needed to establish the potential protective effect of nut consumption on hypertension and vascular reactivity.