Omega-3 Fatty Acids in Food and Pharma: The Enabling Role of Biotechnology

Lipidomics and Anti-Inflammation Activity of Brown Algae, Lobophora sp., in Vietnam

Lobophora sp., belonging to brown macro algae phylum, is found in coral reefs. In this study, the fatty acid composition, lipid classes, polar lipid molecular forms, and bioactivities of this algae have been determined. It follows that five classes including polar lipid (Pol), sterol (ST), free fatty acids (FFA), triacylglycerol (TAG), and hydrocarbon and wax (HW), 23 fatty acids containing 5 PUFAs (ALA, GLA, AA, EPA, and DHA) and 157 molecular types of polar lipid group containing 48 phospholipid molecular forms belonging to 4 subclasses (PI (11), PC (14), PG (22), PA (1)), 45 glycolipid molecular forms classified into 3 subclasses of MGDG (8), DGDG (1), SQDG (36), and 64 betaine lipid molecular forms belonging to 2 subclasses (DGTA (37), DGTS (27)) have been identified for the first time from this algae. Furthermore, both polar lipid (PL) and unpolar lipid (UPL) show the NO inhibition activities with values of IC50 ranging from 52.10 to 66.21 µg/mL. Thus, lipid of this brown algae could promise to be a potential source for application in food, cosmetic, and pharmaceutic industry.

Omega-3 Fatty Acids as Druggable Therapeutics for Neurodegenerative Disorders

Neurodegenerative disorders are commonly associated with a complex pattern of pathophysiological hallmarks, including increased oxidative stress and neuroinflammation, which makes their treatment challenging. Omega-3 Fatty Acids (O3FA) are natural products with reported neuroprotective, anti-inflammatory, and antioxidant effects. These effects have been attributed to their incorporation into neuronal membranes or through the activation of intracellular or recently discovered cell-surface receptors (i.e., Free-Fatty Acid Receptors; FFAR). Molecular docking studies have investigated the roles of O3FA as agonists of FFAR and have led to the development of receptor-specific targeted agonists for therapeutic purposes. Moreover, novel formulation strategies for targeted delivery of O3FA to the brain have supported their development as therapeutics for neurodegenerative disorders. Despite the compelling evidence of the beneficial effects of O3FA for several neuroprotective functions, they are currently only available as unregulated dietary supplements, with only a single FDA-approved prescription product, indicated for triglyceride reduction. This review highlights the relative safety and efficacy of O3FA, their drug-like properties, and their capacity to be formulated in clinically viable drug delivery systems. Interestingly, the presence of cardiac conditions such as hypertriglyceridemia is associated with brain pathophysiological hallmarks of neurodegeneration, such as neuroinflammation, thereby further suggesting potential therapeutic roles of O3FA for neurodegenerative disorders. Taken together, this review article summarizes and integrates the compelling evidence regarding the feasibility of developing O3FA and their synthetic derivatives as potential drugs for neurodegenerative disorders.

Plasma, Urine, and Adipose Tissue Biomarkers of Dietary Intake Differ Between Vegetarian and Non-Vegetarian Diet Groups in the Adventist Health Study-2

BACKGROUND

Differences in food composition, nutrient intake, and various health outcomes have been reported for vegetarians and non-vegetarians in the Adventist Health Study-2 (AHS-2) cohort.

OBJECTIVE

We sought to determine whether biomarkers of dietary intake also differed between individuals classified as vegetarian (vegan, lacto-ovo-vegetarian, pesco-vegetarian, semi-vegetarian) and non-vegetarians based on patterns of consumption of meat, dairy, and eggs.

METHODS

Fasting plasma, overnight urine, and adipose tissue samples were collected from a representative subset of AHS-2 participants classified into 5 diet groups (vegan, lacto-ovo-vegetarian, pesco-vegetarian, semi-vegetarian, non-vegetarian) who also completed food-frequency questionnaires. Diet-related biomarkers including carotenoids, isoflavones, enterolactone, saturated and polyunsaturated fatty acids, and vitamins were analyzed in 840 male and female participants. Multiple linear regression was used to examine the association between diet pattern and biomarker abundance, comparing each of 4 vegetarian dietary groups to non-vegetarians, and adjusted mean values were calculated. Bonferroni correction was applied to control for multiple testing.

RESULTS

Vegans had higher plasma total carotenoid concentrations (1.6-fold, P < 0.0001), and higher excretion of urinary isoflavones (6-fold, P < 0.0001) and enterolactone (4.4-fold) compared with non-vegetarians. Vegans had lower relative abundance of saturated fatty acids including myristic, pentadecanoic, palmitic, and stearic acids (P < 0.0001). Vegans had higher linoleic acid (18:2ω-6) relative to non-vegetarians (23.3% compared with 19.1%) (P < 0.0001), and a higher proportion of total ω-3 fatty acids (2.1% compared with 1.6%) (P < 0.0001). Results overall were similar but less robust for lacto-ovo- and pesco-vegetarians. 1-Methylhistidine was 92% lower in vegans, and lower in lacto-ovo- and pesco-vegetarians by 90% and 80%, respectively, relative to non-vegetarians (P < 0.0001).

CONCLUSION

AHS-2 participants following vegan, and lacto-ovo- or pesco-vegetarian diet patterns have significant differences in plasma, urine, and adipose tissue biomarkers associated with dietary intakes compared with those who consume a non-vegetarian diet. These findings provide some validation for the prior classification of dietary groups within the AHS-2 cohort.

Lipid Composition, Fatty Acids and Sterols in the Seaweeds Ulva armoricana, and Solieria chordalis from Brittany (France): An Analysis from Nutritional, Chemotaxonomic, and Antiproliferative Activity Perspectives

Lipids from the proliferative macroalgae Ulva armoricana (Chlorophyta) and Solieria chordalis (Rhodophyta) from Brittany, France, were investigated. The total content of lipids was 2.6% and 3.0% dry weight for U. armoricana and S. chordalis, respectively. The main fractions of S. chordalis were neutral lipids (37%) and glycolipids (38%), whereas U. armoricana contained mostly neutral lipids (55%). Polyunsaturated fatty acids (PUFA) represented 29% and 15% of the total lipids in U. armoricana and S. chordalis, respectively. In both studied algae, the phospholipids were composed of PUFA for 18%. In addition, PUFA were shown to represent 9% and 4.5% of glycolipids in U. armoricana and S. chordalis, respectively. The essential PUFA were 16:4n-3, 18:4n-3, 18:2n-3, 18:2n-6, and 22:6n-3 in U. armoricana, and 20:4n-6 and 20:5n-3 in S. chordalis. It is important to notice that six 2-hydroxy-, three 3-hydroxy-, and two monounsaturated hydroxy fatty acids were also identified and may provide a chemotaxonomic basis for algae. These seaweeds contained interesting compounds such as squalene, α-tocopherol, cholest-4-en-3-one and phytosterols. The antiproliferative effect was evaluated in vitro on human non-small-cell bronchopulmonary carcinoma line (NSCLC-N6) with an IC50 of 23 μg/mL for monogalactosyldiacylglycerols isolated from S. chordalis and 24 μg/mL for digalactosyldiacylglycerols from U. armoricana. These results confirm the potentialities of valorization of these two species in the fields of health, nutrition and chemotaxonomy.

Development of food-grade nanoemulsions and emulsions for delivery of omega-3 fatty acids: opportunities and obstacles in the food industry

Consumption of biologically active amounts of omega-3 fatty acids is linked to improved human health, which has partly been attributed to their important role in brain development and cardiovascular health. Western diets are relatively low in omega-3 fatty acids and many consumers turn to supplements or functional foods to increase their intake of these healthy lipids. Fish oil is one of the most widely used sources of omega-3 fatty acid for supplementation and has greater health benefits than plant sources because of its higher concentration of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The incorporation of omega-3 fatty acids into foods and beverages is often challenging due to their low water-solubility, poor oxidative stability, and variable bioavailability. Nanoemulsions offer a promising way to incorporate omega-3 fatty acids into liquid food systems like beverages, dressing, sauces, and dips. Nanoemulsions are colloidal dispersions that contain small oil droplets (r<100 nm) that may be able to overcome many of the challenges of fortifying foods and beverages with omega-3 fatty acids. The composition and fabrication of nanoemulsions can be optimized to increase the chemical and physical stability of oil droplets, as well as to increase the bioavailability of omega-3 fatty acids.

Grocery store podcast about omega-3 fatty acids influences shopping behaviors: a pilot study

OBJECTIVES

To determine whether listening to a podcast about omega-3 fatty acids (n-3s) while grocery shopping increased shoppers' awareness about and purchases of seafood and other foods rich in n-3s.

METHODS

Repeated-measures design with a convenience sample (n = 56) of grocery shoppers who listened to the podcast while shopping. Pre- and postintervention semistructured interviews were conducted. The Theory of Reasoned Action was the study's framework.

RESULTS

Shoppers were primarily females (mean age, 41 ± 15.3 years). Their perceived ability to buy [t(55) = 6.27, P < .0001] and perceived importance regarding buying [t(55) = 3.38, P < .01] n-3-rich foods improved significantly. At least 1 n-3 rich food (mean, 1.5 ± 0.8) was purchased by 30%, and 79% planned future purchases.

CONCLUSION AND IMPLICATIONS

Podcasts may effectively communicate nutrition information. More research with a larger sample size is needed to evaluate the effects of the podcast on long-term changes in shopping behavior.

Achieving optimal n-3 fatty acid status: the vegetarian's challenge... or not

The long chain n-3 (omega-3) fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), although originally synthesized by microorganisms in the oceans, are primarily obtained from the consumption of fish. Vegetarians, by definition, do not eat fish and thus consume virtually no EPA and DHA. Because conversion of the plant-derived n-3 fatty acid α-linolenic acid (ALA) to EPA and DHA is very low, n-3 tissue concentrations in vegetarians are lower than in omnivores. This review asks 2 questions: what is the evidence that increased n-3 concentrations reduce the risk of cardiovascular disease in vegetarians, and, if it does, how can vegetarians increase their blood and tissue concentrations of these animal-derived fatty acids? At present, both cardiovascular risk markers and cardiovascular events appear to be significantly reduced in vegetarians compared with those in omnivores. If so, and in the absence of data to show that risk in vegetarians could be even lower with higher n-3 concentrations, then the second question becomes moot. However, the absence of evidence is not evidence of absence; therefore, at our present state of knowledge, increasing n-3 concentrations is not an unreasonable goal for vegetarians. This can be accomplished by a variety of approaches, including increased intakes of ALA, consumption of stearidonic acid-enriched soybean oil (if and when it comes to the market), and the use of supplements containing EPA, DHA, or both derived from nonanimal sources (microalgae, biotech yeast, and, in the future, biotech plant oils).

Omega-3 fatty acids and cardiovascular disease: new developments and applications

The omega-3 fatty acids (FA) found in fish oils, eicosapentaenoic and docosahexaenoic acids (EPA and DHA, respectively), have been extensively studied therapeutically in a wide variety of disease conditions, but in none more than cardiovascular disease (CVD). Our review summarizes mechanisms of action, recent meta-analyses of CVD outcome trials, sources (fish and supplements), and recommendations for use of omega-3 FA in clinical practice. With the ability to now measure the omega-3 FA biostatus through blood tests, patients can achieve cardioprotective levels by either taking fish oil supplements or simply eating more oily fish. Two omega-3 FA formulations (both in the ethyl ester form) have been approved by the US Food and Drug Administration (FDA) for the treatment of patients with very high triglyceride levels (> 500 mg/dL); one contains both EPA and DHA, whereas the other contains only EPA. The agents have been extensively tested in 2 patient populations, those with very high triglycerides and those with triglycerides between 200 and 500 mg/dL while on background statin therapy. In general, treatment with EPA+DHA appears to lower patient triglycerides more effectively, but in those patients with very high triglyceride levels, use of EPA+DHA also raised low-density lipoprotein cholesterol levels, whereas EPA alone did not. Both formulations, at doses that do not lower triglycerides, have been shown to reduce CVD events in some, but not all, studies. Given the favorable risk-to-benefit ratio for these essentially nutritional agents, use is expected to continue to expand.

Effect of stearidonic acid-enriched soybean oil on fatty acid profile and metabolic parameters in lean and obese Zucker rats

Background

Consumption of marine-based oils high in omega-3 polyunsaturated fatty acids (n3PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is known to protect against obesity-related pathologies. It is less clear whether traditional vegetable oils with high omega-6 polyunsaturated fatty acid (n6PUFA) content exhibit similar therapeutic benefits. As such, this study examined the metabolic effects of a plant-based n3PUFA, stearidonic acid (SDA), in polygenic obese rodents.

Methods

Lean (LZR) and obese Zucker (OZR) rats were provided either a standard westernized control diet (CON) with a high n6PUFA to n3PUFA ratio (i.e., 16.2/1.0) or experimental diet modified with flaxseed (FLAX), menhaden (FISH), or SDA oil that resulted in n6PUFA to n3PUFA ratios of 1.7/1.0, 1.3/1.0, and 1.0/0.8, respectively.

Results

After 12 weeks, total adiposity, dyslipidemia, glucose intolerance, and hepatic steatosis were all greater, whereas n3PUFA content in liver, adipose, and muscle was lower in OZR vs. LZR rats. Obese rodents fed modified FISH or SDA diets had lower serum lipids and hepatic fat content vs. CON. The omega-3 index (i.e., ΣEPA + DHA in erythrocyte membrane) was 4.0, 2.4, and 2.0-fold greater in rodents provided FISH, SDA, and FLAX vs. CON diet, irrespective of genotype. Total hepatic n3PUFA and DHA was highest in rats fed FISH, whereas both hepatic and extra-hepatic EPA was higher with FISH and SDA groups.

Conclusions

These data indicate that SDA oil represents a viable plant-derived source of n3PUFA, which has therapeutic implications for several obesity-related pathologies.

Long-chain omega-3 fatty acids: time to establish a dietary reference intake

The beneficial effects of consuming omega-3 polyunsaturated fatty acids (n-3 PUFAs), specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on cardiovascular health have been studied extensively. To date, there is no dietary reference intake (DRI) for EPA and DHA, although many international authorities and expert groups have issued dietary recommendations for them. Given the substantial new evidence published since the last Institute of Medicine (IOM) report on energy and macronutrients, released in 2002, there is a pressing need to establish a DRI for EPA and DHA. In order to set a DRI, however, more information is needed to define the intakes of EPA and DHA required to reduce the burden of chronic disease. Information about potential gender- or race-based differences in requirements is also needed. Given the many health benefits of EPA and DHA that have been described since the 2002 IOM report, there is now a strong justification for establishing a DRI for these fatty acids.

Oxidized fatty acid analysis by charge-switch derivatization, selected reaction monitoring, and accurate mass quantitation

A highly sensitive, specific, and robust method for the analysis of oxidized metabolites of linoleic acid (LA), arachidonic acid (AA), and docosahexaenoic acid (DHA) was developed using charge-switch derivatization, liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI MS/MS) with selected reaction monitoring (SRM) and quantitation by high mass accuracy analysis of product ions, thereby minimizing interferences from contaminating ions. Charge-switch derivatization of LA, AA, and DHA metabolites with N-(4-aminomethylphenyl)-pyridinium resulted in a 10- to 30-fold increase in ionization efficiency. Improved quantitation was accompanied by decreased false positive interferences through accurate mass measurements of diagnostic product ions during SRM transitions by ratiometric comparisons with stable isotope internal standards. The limits of quantitation were between 0.05 and 6.0pg, with a dynamic range of 3 to 4 orders of magnitude (correlation coefficient r(2)>0.99). This approach was used to quantitate the levels of representative fatty acid metabolites from wild-type (WT) and iPLA2γ(-/-) mouse liver identifying the role of iPLA2γ in hepatic lipid second messenger production. Collectively, these results demonstrate the utility of high mass accuracy product ion analysis in conjunction with charge-switch derivatization for the highly specific quantitation of diminutive amounts of LA, AA, and DHA metabolites in biologic systems.

Fatty acid profiling of tropical marine macroalgae: an analysis from chemotaxonomic and nutritional perspectives

The lipid and fatty acid (FA) compositions for 100 marine macroalgae were determined and discussed from the context of chemotaxonomic and nutritional perspectives. In general, the lipid contents in macroalgae were low (2.3-20 mg/g fr. wt.) but with substantially high amounts of nutritionally important polyunsaturated fatty acids (PUFAs) such as LA, ALA, STA, AA, EPA and DHA, that ranged from 10% to 70% of TFAs. More than 90% of the species showed nutritionally beneficial n6/n3 ratio (0.1:1-3.6:1) (p≤0.001). A closer look at the FA data revealed characteristic chemotaxonomic features with C18 PUFAs (LA, ALA and STA) being higher in Chlorophyta, C20 PUFAs (AA and EPA) in Rhodophyta while Phaeophyta depicted evenly distribution of C18 and C20 PUFAs. The ability of macroalgae to produce long-chain PUFAs could be attributed to the coupling of chloroplastic FA desaturase enzyme system from a photosynthetic endosymbiont to the FA desaturase/elongase enzyme system of a non-photosynthetic eukaryotic protist host. Further, the principal component analysis segregated the three macroalgal groups with a marked distinction of different genera, families and orders, Hierarchical cluster analyses substantiated the phylogenetic relationships of all orders investigated except for those red algal taxa belonging to Gigartinales, Ceramiales, Halymeniales and Rhodymeniales for which increased sampling effort is required to infer a conclusion. Also, the groups deduced from FA compositions were congruent with the clades inferred from nuclear and plastid genome sequences. This study further indicates that FA signatures could be employed as a valid chemotaxonomic tool to differentiate macroalgae at higher taxonomic levels such as family and orders.

Omega-3 fatty acid supplementation and cardiovascular disease

Epidemiological studies on Greenland Inuits in the 1970s and subsequent human studies have established an inverse relationship between the ingestion of omega-3 fatty acids [C(20-22) ω 3 polyunsaturated fatty acids (PUFA)], blood levels of C(20-22) ω 3 PUFA, and mortality associated with cardiovascular disease (CVD). C(20-22) ω 3 PUFA have pleiotropic effects on cell function and regulate multiple pathways controlling blood lipids, inflammatory factors, and cellular events in cardiomyocytes and vascular endothelial cells. The hypolipemic, anti-inflammatory, anti-arrhythmic properties of these fatty acids confer cardioprotection. Accordingly, national heart associations and government agencies have recommended increased consumption of fatty fish or ω 3 PUFA supplements to prevent CVD. In addition to fatty fish, sources of ω 3 PUFA are available from plants, algae, and yeast. A key question examined in this review is whether nonfish sources of ω 3 PUFA are as effective as fatty fish-derived C(20-22) ω 3 PUFA at managing risk factors linked to CVD. We focused on ω 3 PUFA metabolism and the capacity of ω 3 PUFA supplements to regulate key cellular events linked to CVD. The outcome of our analysis reveals that nonfish sources of ω 3 PUFA vary in their capacity to regulate blood levels of C(20-22) ω 3 PUFA and CVD risk factors.