Incorporation Of Eicosapentaenoic Acid Research Articles

Compared with Daily, Weekly n–3 PUFA Intake Affects the Incorporation of Eicosapentaenoic Acid and Docosahexaenoic Acid into Platelets and Mononuclear Cells in Humans1–3

Consumption of oily fish is sporadic, whereas controlled intervention studies of n–3 (ω-3) fatty acids usually provide capsules containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) as a daily dose. This methodologic study explored whether there are differences in the short-, medium-, and long-term incorporation of EPA and DHA into blood plasma and cells with the provision of identical amounts of EPA and DHA, equivalent to 2 oily fish servings per week (or 6.54 g/wk EPA and DHA), either intermittently (i.e., 1 portion twice per week) or continuously (i.e., divided into daily amounts). The study was part of a randomized, double-blind controlled intervention lasting 12 mo, with participants stratified by age and sex. There were 5 intervention groups, 2 of which are reported here: the 2 intermittent portions (2I) and 2 continuous portions (2C) groups. EPA and DHA were measured in plasma phosphatidylcholine, platelets, and blood mononuclear cells (MNCs) at 9 time points. Sixty-five participants completed the study (2I group, n = 30, mean age of 49.2 y; 2C group, n = 35, mean age of 50.6 y). The incorporation pattern over the 12-mo intervention was different between the 2 groups in all samples (P < 0.0001, time × treatment interaction). At the end of the 12-mo intervention, the 2C group had higher EPA, DHA, and EPA + DHA in platelets (all P < 0.01) and higher EPA and EPA + DHA in MNCs (both P < 0.05) compared with the 2I group. No significant differences were shown for plasma phosphatidylcholine EPA (P = 0.1), DHA (P = 0.15), EPA + DHA (P = 0.07), or MNC DHA (P = 0.06). In conclusion, the pattern of consumption does affect the incorporation of EPA and DHA into cells used as biomarkers of intake. The differences identified here need to be considered in the design of studies and when extrapolating results from continuous capsule-based intervention studies to dietary guidelines for oily fish consumption. This trial was registered at www.controlled-trials.com> as ISRCTN48398526.

Influencing mitochondrial membrane composition and bioenergetics through omega-3 supplementation.

Influencing mitochondrial membrane composition and bioenergetics through omega-3 supplementation.

The effect of EPA and DHA on platelets treated with multiple agonists found in the thrombus core (671.3)

The omega‐3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been consistently associated with reduced platelet function, and more recently, with impaired thrombin generation. However, almost all studies to date have focused on how EPA and DHA alter platelet physiology in response to monotypic agonist stimulation. This reductionist approach does not recapitulate the complex chemical environment found in a developing thrombus. Therefore, we asked if platelets treated with multiple agonists like those found in the thrombus core would also display EPA and DHA‐mediated inhibition. We found that optical aggregometry and dense granule secretion was diminished after EPA and DHA incorporation in platelets stimulated with the core clot agonists. We also noted a reduction in both the protein content of platelet lipid rafts and thrombin generation after core agonist stimulation, consistent with our earlier observations. Transmission electron micrographic imaging also established that EPA and DHA‐treated platelets showed moderate ultrastructural malformations after core agonist treatment. These results all suggest that EPA and DHA can abrogate platelet signaling responses within the core of a developing thrombus, further illustrating the potential health benefits of increased EPA and DHA intake.Grant Funding Source: Supported by an Institutional Development Award (IDeA) from the NIH/NIGMS, #P20GM103443

Anticolorectal cancer activity of the omega-3 polyunsaturated fatty acid eicosapentaenoic acid

BackgroundOral administration of the omega-3 fatty acid eicosapentaenoic acid (EPA), as the free fatty acid (FFA), leads to EPA incorporation into, and reduced growth of, experimental colorectal cancer liver metastases...

Metabolic incorporation of unsaturated fatty acids into boar spermatozoa lipids and de novo formation of diacylglycerols

Lipids play an important role in the maturation, viability and function of sperm cells. In this study, we examined the neutral and polar lipid composition of boar spermatozoa by thin-layer chromatography/mass spectrometry. Main representatives of the neutral lipid classes were diacylglycerols containing saturated (myristoyl, palmitoyl and stearoyl) fatty acyl residues. Glycerophosphatidylcholine and glycerophosphatidylethanolamine with alk(en)yl ether residues in the sn-1 position and unsaturated long chained fatty acyl residues in sn-2 position were identified as the most prominent polar lipids. The only glycoglycerolipid was sulfogalactosylglycerolipid carrying 16:0-alkyl- and 16:0-acyl chains. Using stable isotope-labelling, the metabolic incorporation of exogenously supplied fatty acids was analysed. Boar spermatozoa incorporated hexadecenoic (16:1), octadecenoic (18:1), octadecadienoic (18:2) and octadecatrienoic (18:3) acids primarily in the diacylglycerols and glycerophosphatidylcholines. In contrast, incorporation of eicosapentaenoic acid (20:5) was not detected. The analysis of molecular species composition subsequent to the incorporation of exogenous [14C]-octadecadienoic acid suggests two pathways for incorporation of exogenous fatty acids into glycerophosphatidylcholine: (1) de novo synthesis of glycerophosphatidylcholine via the CDP-choline pathway and (2) reacylation of lysophosphatidylcholine via an acyltransferase.

The low levels of eicosapentaenoic acid in rat brain phospholipids are maintained via multiple redundant mechanisms

Brain eicosapentaenoic acid (EPA) levels are 250- to 300-fold lower than docosahexaenoic acid (DHA), at least partly, because EPA is rapidly β-oxidized and lost from brain phospholipids. Therefore, we examined if β-oxidation was necessary for maintaining low EPA levels by inhibiting β-oxidation with methyl palmoxirate (MEP). Furthermore, because other metabolic differences between DHA and EPA may also contribute to their vastly different levels, this study aimed to quantify the incorporation and turnover of DHA and EPA into brain phospholipids. Fifteen-week-old rats were subjected to vehicle or MEP prior to a 5 min intravenous infusion of 14C-palmitate, 14C-DHA, or 14C-EPA. MEP reduced the radioactivity of brain aqueous fractions for 14C-palmitate-, 14C-EPA-, and 14C-DHA-infused rats by 74, 54, and 23%, respectively; while it increased the net rate of incorporation of plasma unesterified palmitate into choline glycerophospholipids and phosphatidylinositol and EPA into ethanolamine glycerophospholipids and phosphatidylserine. MEP also increased the synthesis of n-3 docosapentaenoic acid (n-3 DPA) from EPA. Moreover, the recycling of EPA into brain phospholipids was 154-fold lower than DHA. Therefore, the low levels of EPA in the brain are maintained by multiple redundant pathways including β-oxidation, decreased incorporation from plasma unesterified FA pool, elongation/desaturation to n-3 DPA, and lower recycling within brain phospholipids.

The effect of non‐marine vs. marine sources of the omega‐3 fatty acids, DHA and EPA, on serum lipoproteins

Fish oil (FO) is a marine source of omega‐3 fatty acids, eicosapentaenoic acid (EPA) and docosahexanaenoic acid (DHA), and has been shown to improve heart health. Our objective was to determine the cardiovascular effects of non‐marine sources, algae oil (AO) and yeast oil (YO), as compared to fish oil (FO). Male ICR mice (8‐wk, n=100) were randomly assigned to dietary groups: soy oil (SO) (no DHA or EPA), FO (DHA + EPA), AO (DHA), YO (EPA), or AO+YO (DHA + EPA) for 2 or 4 wk. Serum triglycerides (TG), total cholesterol (TC), and HDL‐cholesterol were measured and non‐HDL cholesterol (NHDLC) was calculated. Liver DHA and EPA concentration were determined. The FO diet lowered all fractions of plasma lipids and was the only diet to reduce TG (p&lt;0.05). YO, alone and in combination with AO, reduced TC and NHDLC at 4 wks. At 2 wk, AO reduced TC and NHDLC (p&lt;0.05). The AO and AO+YO‐fed mice incorporated less DHA into liver lipids compared to the FO‐fed mice at 2 wk (p&lt;0.05). There were no differences in the incorporation of EPA. Therefore, non‐marine sources do not appear to be as effective as FO at reducing serum lipids.

Evaluation of suppressive and pro-resolving effects of EPA and DHA in human primary monocytes and T-helper cells

Despite their beneficial anti-inflammatory properties, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may increase the infection risk at high doses, likely by generating an immune-depressed state. To assess the contribution of different immune cell populations to the immunomodulatory fatty acid effect, we comparatively investigated several aspects of inflammation in human T-helper (Th) cells and monocytes. Both fatty acids, but DHA to a lesser extent compared with EPA, selectively and dose-dependently reduced the percentage of cytokine-expressing Th cells in a peroxisome proliferator-activated receptor (PPAR)γ-dependent fashion, whereas the expression of the cell surface marker CD69 was unaltered on activated T cells. In monocytes, both EPA and DHA increased interleukin (IL)-10 without affecting tumor necrosis factor (TNF)-α and IL-6. Cellular incorporation of EPA and DHA occurred mainly at the expense of arachidonic acid. Concomitantly, thromboxane B (TXB)2 and leukotriene B (LTB)4 in supernatants decreased, while levels of TXB3 and LTB5 increased. This increase was independent of activation and in accordance with cyclooxygenase expression patterns in monocytes. Moreover, EPA and DHA gave rise to a variety of mono- and trihydroxy derivatives of highly anti-inflammatory potential, such as resolvins and their precursors. Our results suggest that EPA and DHA do not generally affect immune cell functions in an inhibitory manner but rather promote pro-resolving responses.

Incorporation of eicosapentaenoic and docosahexaenoic acids into lipid pools when given as supplements providing doses equivalent to typical intakes of oily fish

Background: Estimation of the intake of oily fish at a population level is difficult. The measurement of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in biological samples may provide a useful biomarker of intake.Objective: We identified the most appropriate biomarkers for the assessment of habitual oily fish intake and changes in intake by elucidating the dose- and time-dependent response of EPA and DHA incorporation into various biological samples that represent roles in fatty acid transport, function, and storage.Design: This was a double-blind, randomized, controlled intervention trial in 204 men and women that lasted 12 mo. EPA and DHA capsules were provided in a manner to reflect sporadic consumption of oily fish (ie, 1, 2, or 4 times/wk). EPA and DHA were assessed at 9 time points over 12 mo in 9 sample types (red blood cells, mononuclear cells, platelets, buccal cells, adipose tissue, plasma phosphatidylcholine, triglycerides, cholesteryl esters, and nonesterified fatty acids).Results: A dose response (P < 0.05) was observed for EPA and DHA in all pools except for red blood cell EPA (P = 0.057). EPA and DHA measures in plasma phosphatidylcholine and platelets were best for the discrimination between different intakes (P < 0.0001). The rate of incorporation varied between sample types, with the time to maximal incorporation ranging from days (plasma phosphatidylcholine) to months (mononuclear cells) to >12 mo (adipose tissue).Conclusions: Plasma phosphatidylcholine EPA plus DHA was identified as the most suitable biomarker of acute changes in EPA and DHA intake, and platelet and mononuclear cell EPA plus DHA were the most suitable biomarkers of habitual intake. This trial was registered at Current Controlled Trials (www.controlled-trials.com) as ISRCTN48398526.

A short-term n-3 DPA supplementation study in humans

Despite the detailed knowledge of the absorption and incorporation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) into plasma lipids and red blood cells (RBC) in humans, very little is known about docosapentaenoic acid (DPA, 22:5 n-3). The aim of this study was to investigate the uptake and incorporation of pure DPA and EPA into human plasma and RBC lipids. Ten female participants received 8 g of pure DPA or pure EPA in randomized crossover double-blinded manner over a 7-day period. The placebo treatment was olive oil. Blood samples were collected at days zero, four and seven, following which the plasma and RBC were separated and used for the analysis of fatty acids. Supplementation with DPA significantly increased the proportions of DPA in the plasma phospholipids (PL) (by twofold) and triacylglycerol (TAG) fractions (by 2.3-fold, day 4). DPA supplementation also significantly increased the proportions of EPA in TAG (by 3.1-fold, day 4) and cholesterol ester (CE) fractions (by 2.0-fold, day 7) and of DHA in TAG fraction (by 3.1-fold, day 4). DPA proportions in RBC PL did not change following supplementation. Supplementation with EPA significantly increased the proportion of EPA in the plasma CE and PL fractions, (both by 2.7-fold, day 4 and day 7) and in the RBC PL (by 1.9-fold, day 4 and day 7). EPA supplementation did not alter the proportions of DPA or DHA in any lipid fraction. These results showed that within day 4 of supplementation, DPA and EPA demonstrated different and specific incorporation patterns. The results of this short-term study suggest that DPA may act as a reservoir of the major long-chain n-3 fatty acids (LC n-3 PUFA) in humans.

The omega‐3 polyunsaturated fatty acid eicosapentaenoic acid inhibits mouse MC‐26 colorectal cancer cell liver metastasis via inhibition of PGE2‐dependent cell motility

The omega-3 polyunsaturated fatty acid (PUFA) eicosapentaenoic acid (EPA) has antineoplastic activity at early stages of colorectal carcinogenesis, relevant to chemoprevention of colorectal cancer (CRC). We tested the hypothesis that EPA also has anti-CRC activity at later stages of colorectal carcinogenesis, relevant to treatment of metastatic CRC, via modulation of E-type PG synthesis. A BALB/c mouse model, in which intrasplenic injection of syngeneic MC-26 mouse CRC cells leads to development of liver metastases, was used. Dietary EPA was administered in the free fatty acid (FFA) form for 2 weeks before and after ultrasound-guided intrasplenic injection of 1 × 10(6) MC-26 cells (n= 16 each group). Treatment with 5% (w w(-1)) EPA-FFA was associated with a reduced MC-26 mouse CRC cell liver tumour burden compared with control animals (median liver weight 1.03 g vs. 1.62 g; P < 0.034). Administration of 5% EPA-FFA was also linked to a significant increase in tumour EPA incorporation and lower intratumoural PGE(2) levels (with concomitant increased production of PGE(3)). Liver tumours from 5% EPA-FFA- treated mice demonstrated decreased 5-bromo-2-deoxyuridine-positive CRC cell proliferation and reduced phosphorylated ERK 1/2 expression at the invasive edge of tumours. A concentration-dependent reduction in MC-26 CRC cell Transwell® migration following EPA-FFA treatment (50-200 µM) in vitro was rescued by exogenous PGE(2) (10 µM) and PGE(1)-alcohol (1 µM). EPA-FFA inhibits MC-26 CRC cell liver metastasis. EPA incorporation is associated with a 'PGE(2) to PGE(3) switch' in liver tumours. Inhibition of PGE(2)-EP(4) receptor-dependent CRC cell motility probably contributes to the antineoplastic activity of EPA.

Exogenous modification of platelet membranes with the omega‐3 fatty acids DHA and EPA impairs thrombogenesis

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are associated with lower risk for adverse cardiovascular events. EPA and DHA‐enhanced platelets exhibit relatively normal platelet aggregation characteristics, suggesting that cardioprotective mechanisms are not inherent to platelet reactivity. We hypothesize that EPA and DHA incorporation hinders platelet‐mediated thrombin production. To this end, platelet membranes were modified by exogenous addition of EPA and DHA to whole blood or platelet‐rich plasma followed by thrombin generation assays. Whole blood treatment inhibited occlusive thrombus formation when perfused over collagen‐coated surfaces compared to matched vehicle controls. EPA and DHA‐treated platelets also showed a kinetic impairment of thrombin generation as measured by both thrombin‐specific substrate conversion and thrombin precursor protein levels in the presence of Factor Xa and prothrombin. A functional deficiency in thrombin production was observed as EPA and DHA‐treated blood formed more diffuse thrombi and less fibrin versus matched controls after perfusion across collagen‐coated surfaces. These results strongly suggest that EPA and DHA impair platelet‐mediated thrombin generation, providing a unique cellular mechanism behind the cardioprotective phenotype seen after increased omega‐3 fatty acid intake. Funded by NIH NCRR 2 P20 RR016479.

Effects of duration of treatment and dosage of eicosapentaenoic acid and stearidonic acid on red blood cell eicosapentaenoic acid content

Objective The purpose of this randomized, controlled, parallel group study was to characterize the relationships between dosages of stearidonic acid (SDA) and eicosapentaenoic acid (EPA), and incorporation of EPA into red blood cell (RBC) membranes over time. Methods Healthy subjects ( n=131) received capsules with placebo (safflower oil), SDA (0.43, 1.3, 2.6, or 5.2 g/d) or EPA (0.44, 1.3, or 2.7 g/d) for 12 weeks. RBC fatty acids were analyzed biweekly. Results RBC %EPA increased in all EPA and SDA groups ( p<0.02 vs. control) except the 0.43 g/d SDA group ( p=0.187). For theoretical intakes of EPA of 0.25, 0.5, and 0.89 g/d, the amounts of SDA needed to achieve equivalent RBC EPA enrichment were 0.61, 1.89, and 5.32 g/d (conversion efficiencies of 41%, 26%, and 17%), respectively. Conclusions SDA increased RBC %EPA in a dosage and time-dependent manner at intakes as low as 1.3 g/d.

Response surface modelling of the production of structured lipids from soybean oil using Rhizomucor miehei lipase

The production of structured lipids (SLs) by the acidolysis of soybean oil (SO) with a free fatty acid (FFA) mixture obtained from Brazilian sardine oil, catalysed by Rhizomucor miehei lipase (Lipozyme RM IM) in a solvent-free medium, was optimised by response surface methodology (RSM) using a three-factor central composite rotatable design. The best reaction conditions to achieve an adequate n-6/n-3 FA ratio were: sardine-FFA:SO mole ratio of 3:1, initial water content of the enzyme of 0.87% w/w, reaction time of 12h, reaction temperature of 40°C and 10% by weight of the enzyme (% w/w). Under these conditions, the incorporation of eicosapentaenoic acid (EPA)+docosahexaenoic acid (DHA) into the soybean oil reached 9.2% (% of the total FAs), leading to a significant reduction in the n-6/n-3 FA ratio from 11:1 to 3:1. Analysis of variance (ANOVA) showed that 95% (R2=0.95) of the observed variation was explained by the model. Lack of fit analysis revealed a non-significant value for the model equation, indicating that the regression equation was adequate for predicting the degree of EPA+DHA incorporation under any combination of values of the variables. Easy ambient sonic-spray ionisation mass spectrometry (EASI-MS) was used for instantaneous characterisation of TAGs. After the enzymatic reaction, a great variety of new TAGs were formed containing EPA, DHA or both in the same molecule.

Importance of the relative levels of dietary arachidonic acid and eicosapentaenoic acid for culture performance of gilthead seabream (Sparus aurata) larvae

The effect of different arachidonic acid (ARA) dietary contents at several dietary eicosapentaenoic acid (EPA) levels on the growth, survival and biochemical composition of gilthead seabream larvae was studied to better define the importance of this fatty acid as a function of EPA. Larvae of 18 days were fed one of the five isonitrogenous and isolipidic microdiets with three different EPA (0.3%, 2% and 4%) and ARA amounts (0.1%, 0.6% and 1.2%). Although a dietary increase in either ARA or EPA alone did not improve survival significantly, the increase in both fatty acids significantly enhanced growth and survival, suggesting an optimum dietary value of EPA:ARA close to 4:1.2. Dietary ARA was more efficiently incorporated into larval tissues than EPA. Increased dietary EPA or ARA contents reduced the incorporation of ARA or EPA into larval lipids, indicating their competition as substrates for different enzymes. The possible negative effect of further elevation of dietary ARA and its competition with EPA for phospholipids synthesis deserves further studies in marine fish larvae.

Importance of dietary arachidonic acid for the growth, survival and stress resistance of larval European sea bass (Dicentrarchus labrax) fed high dietary docosahexaenoic and eicosapentaenoic acids

Together with docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), arachidonic acid (ARA) is being considered to be an essential fatty acid in marine fish larval diets. The objective of the present study was to determine the importance of dietary ARA levels for larval European sea bass performance, when EPA and DHA are also present in the diet. Eighteen-day-old larvae were fed, for 14 days, gelatine-based microdiets containing the following ARA levels: 0.3%, 0.6% or 1.2%. Elevation of dietary ARA up to 1.2% showed a positive correlation with larval survival and a significant improvement in the specific growth rates, body weight and total length. Arachidonic acid was efficiently incorporated into larval lipids, even at a higher proportion than that in the diets. Increased accumulation of ARA did not affect the incorporation of DHA or EPA from the diet into larval total lipids. A significant positive correlation was found between dietary ARA levels and survival after handling stress, indicating the importance of this fatty acid in sea bass larvae response to acute stressors. The results show the importance of ARA for sea bass larvae, but higher dietary levels should be tested to determine whether there is a negative effect of ARA in sea bass as reported for other species.

Preparation of TiO 2-loaded nanocapsules and their sun protection behaviors

Titanium dioxide (TiO 2) sol (TS) or TiO 2 nanoparticles with chitosan shell were encapsulated to enhance their sun protection abilities. Nanocapsules loaded with TiO 2 were evaluated for their ultraviolet (UV) absorption and UV protection rate. The effect of eicosapentaenoic acid (EPA) incorporation into the nanocapsules was examined in relation to UV absorption. The particle size of TiO 2 crystallites in TS was below 30 nm, which was considerably smaller than that of a commercial TiO 2 (P25 TiO 2) particles. In the encapsulation of TiO 2 with chitosan, the loading efficiencies of TS were higher than those of P25 TiO 2. The sizes of the nanocapsules loaded with TiO 2 particles ranged from 30 to 80 nm. The absorption range of irradiation wavelength was enlarged by the incorporation of EPA into the nanocapsules. The TS-loaded nanocapsules exhibited a high UV protection rate of up to 95% to both UV-A and UV-B.

Lipase inhibitor orlistat decreases incorporation of eicosapentaenoic and docosahexaenoic acids in rat tissues

Orlistat is a gastric and pancreatic lipases inhibitor that is often prescribed to obese subjects. Orlistat has been shown to decrease the absorption of biologically important lipophilic micronutrients such as liposoluble vitamins. We hypothesized that long-term administration of orlistat may lower the incorporation of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) in blood lipids and tissues. This hypothesis was tested in rats fed a diet supplemented with fish oil as a source of n-3 LC-PUFA. Male Wistar rats (n = 18) were divided into 3 groups and fed experimental high-fat diets containing fish oil (control diet) or fish oil plus orlistat (200 and 400 mg/kg of diet) over the course of 3 weeks. Fat absorption and the level of eicosapentaenoic acid (EPA) and docosahexaenoic acid, among other fatty acids, in red blood cells, plasma, liver, and spleen, were measured at the end of the experimental period. The results show that at 200 mg and 400 mg/kg of diet orlistat lowers fat absorption by 9% (P = .008) and 54% (P = .008). Orlistat given at the higher level induced a reduction of the incorporation of EPA in red blood cell (-45%; P = .006) and in plasma (-34%; P = .026) compared to the control group. Our results confirmed that administration of orlistat reduces incorporation of n-3 LC-PUFA in blood lipids and tissues in a rat model.

Influence of an eicosapentaenoic and docosahexaenoic acid-enriched enteral nutrition formula on plasma fatty acid composition and biomarkers of insulin resistance in the elderly

n-3 Polyunsaturated fatty acids may improve cardiovascular outcomes in elderly. The aim of this study was to determine the effect of feeding elderly patients exclusively with an n-3 polyunsaturated fatty acid-enriched diet specifically designed for enteral nutrition for 6 months, evaluating modifications in plasma fatty acid profile and some biomarkers of insulin resistance (IR). Thirty-two patients >65 years were fed a new enteral formula (T-Diet Plus) containing 75 mg/l of eicosapentaenoic acid (EPA) and 35 mg/l of docosahexaenoic acid (DHA) and 33 were fed an enteral diet intended for elderly (Jevity). Blood samples were drawn at the beginning and after 3 and 6 months of feeding. Plasma lipids, total plasma and lipid fraction fatty acid profiles, and some IR-associated adipokines were analysed. Feeding on T-Diet Plus allowed EPA and DHA incorporation into plasma lipids and normalised blood triacylglycerols (TAG) levels after 3 months without major changes in IR, leptin and adiponectin. Feeding the elderly exclusively with an enteral formula enriched with EPA and DHA improves their plasma lipid fatty acid profile and lowers TAG, a well known cardiovascular risk biomarker, without affecting IR.

Effect on red blood cell membrane fatty acids of diets enriched with different sources of n‐3 fatty acids in healthy adults

BackgroundConsumption of n‐3 fatty acids from algal‐oil supplements and plant sources produce health benefits, which may be dependent on the incorporation of eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA) into cell membranes.Aim and MethodsTo determine if plant sources (flaxseed oil and walnuts) of á‐linolenic acid (ALA) produce similar change in red blood cell (RBC) membrane fatty acids as algal‐oil (EPA/DHA) supplements, we performed a randomized cross‐over study (3 8‐week study periods) in 24 healthy adults (15 women, 9 men; mean±SE age 42±2.7 years; BMI 25.4±0.9 kg/m2). Under controlled feeding conditions, subjects consumed eucaloric lacto‐ovo vegetarian diets [Control, ALA (6‐7g/2400 kcal/d), EPA/DHA (0.20/0.72g EPA/DHA per 2400 kcal/d), and Combination (ALA + EPA/DHA)]. Fasting EPA and DHA levels were measured at baseline and at week 8 for the 3 study periods. Mixed model analyses were performed.ResultsIncreased EPA levels were observed in the RBC membrane with consumption of the EPA/DHA (41%, p&lt;0.0001), ALA (54%, p=0.0064) and Combination (101%, p&lt;0.0001) diets. DHA levels increased with consumption of the EPA/DHA (49%, p&lt;0.0001) and Combination (36%, p=0.0025) diets.ConclusionN‐3 fatty acids from algal‐oil and plant sources produce similar increases in RBC membrane EPA levels; however DHA levels increased only in the algal‐oil containing diets.