scholarly journals Very long-chain n-3 fatty acids and human health: fact, fiction and the future

2017 ◽  
Vol 77 (1) ◽  
pp. 52-72 ◽  
Author(s):  
P. C. Calder
Keyword(s):  
Fatty Acids ◽  
Cell Signalling ◽  
Docosapentaenoic Acid ◽  
Future Research ◽  
Depth Dose ◽  
Epa And Dha ◽  
Wide Range ◽  
Clinical Benefits ◽  
And Function ◽  
Long Chain

EPA and DHA appear to be the most important n-3 fatty acids, but roles for n-3 docosapentaenoic acid are now also emerging. Intakes of EPA and DHA are usually low, typically below those recommended. Increased intakes result in higher concentrations of EPA and DHA in blood lipids, cells and tissues. Increased content of EPA and DHA modifies the structure of cell membranes and the function of membrane proteins. EPA and DHA modulate the production of lipid mediators and through effects on cell signalling can alter the patterns of gene expression. Through these mechanisms, EPA and DHA alter cell and tissue responsiveness in a way that often results in more optimal conditions for growth, development and maintenance of health. DHA has vital roles in brain and eye development and function. EPA and DHA have a wide range of physiological roles, which are linked to certain health or clinical benefits, particularly related to CVD, cancer, inflammation and neurocognitive function. The benefits of EPA and DHA are evident throughout the life course. Future research will include better identification of the determinants of variation of responses to increased intake of EPA and DHA; more in-depth dose–response studies of the effects of EPA and DHA; clearer identification of the specific roles of EPA, docosapentaenoic acid and DHA; testing strategies to enhance delivery of n-3 fatty acids to the bloodstream; and exploration of sustainable alternatives to fish-derived very long-chain n-3 fatty acids.

scholarly journals Do Eicosapentaenoic Acid and Docosahexaenoic Acid Have the Potential to Compete against Each Other?

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3718
Author(s):  
Anandita Pal ◽  
Adam H. Metherel ◽  
Lauren Fiabane ◽  
Nicole Buddenbaum ◽  
Richard P. Bazinet ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Docosahexaenoic Acid ◽  
Eicosapentaenoic Acid ◽  
Docosapentaenoic Acid ◽  
Western Diet ◽  
Dietary Recommendations ◽  
Membrane Phospholipids ◽  
Beneficial Effects ◽  
Epa And Dha ◽  
Wide Range

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are n-3 polyunsaturated fatty acids (PUFAs) consumed in low abundance in the Western diet. Increased consumption of n-3 PUFAs may have beneficial effects for a wide range of physiological outcomes including chronic inflammation. However, considerable mechanistic gaps in knowledge exist about EPA versus DHA, which are often studied as a mixture. We suggest the novel hypothesis that EPA and DHA may compete against each other through overlapping mechanisms. First, EPA and DHA may compete for residency in membrane phospholipids and thereby differentially displace n-6 PUFAs, which are highly prevalent in the Western diet. This would influence biosynthesis of downstream metabolites of inflammation initiation and resolution. Second, EPA and DHA exert different effects on plasma membrane biophysical structure, creating an additional layer of competition between the fatty acids in controlling signaling. Third, DHA regulates membrane EPA levels by lowering its rate of conversion to EPA’s elongation product n-3 docosapentaenoic acid. Collectively, we propose the critical need to investigate molecular competition between EPA and DHA in health and disease, which would ultimately impact dietary recommendations and precision nutrition trials.

THE INTERACTIONS OF VERTEBRATES AND INVERTEBRATES IN PEATLANDS AND MARSHES

1987 ◽  
Vol 119 (S140) ◽  
pp. 15-30 ◽  
Author(s):  
Henry R. Murkin ◽  
Bruce D.J. Batt
Keyword(s):  
Current Knowledge ◽  
Life Cycles ◽  
Future Research ◽  
Aquatic Environments ◽  
Research Needs ◽  
Avian Community ◽  
Wide Range ◽  
Dead Plant ◽  
Living Organisms ◽  
And Function

AbstractThis paper reviews the interactions of vertebrates and invertebrates in peatlands and marshes to assess current knowledge and future research needs. Living organisms may interact through a number of direct trophic and nutrient pathways and a variety of non-trophic, habitat-dependent relationships. Freshwater marshes and peatlands are dynamic aquatic environments and organisms that occupy these areas must be adapted to a wide range of environmental conditions. The avian community illustrates the main interactions of invertebrates and vertebrates in peatlands and marshes. Waterfowl, along with fish and furbearers, are the most economically important vertebrates using these habitats. Each of these groups has important trophic and habitat links to the invertebrates within wetlands.The most common interaction between vertebrates and invertebrates is the use of invertebrates as food by vertebrates. Few studies, however, have dealt with trophic dynamics or secondary production within wetlands. Waterfowl, fish, and many other wetland vertebrates, during all or part of their life cycles, regularly feed on invertebrates. Some invertebrates are vectors of disease and parasites to vertebrates. Vertebrates can directly affect the structural substrate that invertebrates depend on as habitat through consumption of macrophytes or through the use of living and dead plant material in the construction of houses and nests. Conversely, herbivorous invertebrates may directly affect the survival and distribution of macrophytes in wetlands. Macrophyte distribution, in turn, is an important factor in determining vertebrate use of wetlands. The general lack of both taxonomic and ecological information on invertebrates in wetlands is the main hindrance to future elucidation of vertebrate–invertebrate interactions in these environments. Development of invertebrate sampling techniques suitable for wetland habitats also is necessary. More specific research needs must be met to develop a better understanding of the structure and function of these dynamic systems.

scholarly journals Alpha-Linolenic and Linoleic Fatty Acids in the Vegan Diet: Do They Require Dietary Reference Intake/Adequate Intake Special Consideration?

Nutrients ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2365 ◽  
Author(s):  
Burns-Whitmore ◽  
Froyen ◽  
Heskey ◽  
Parker ◽  
San Pablo
Keyword(s):  
Fatty Acids ◽  
Cold Water ◽  
Vegan Diet ◽  
Special Consideration ◽  
Animal Origin ◽  
Dietary Reference Intake ◽  
Adequate Intake ◽  
Alpha Linolenic Acid ◽  
Epa And Dha ◽  
Long Chain

Good sources of the long-chain n-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) include cold-water fish and seafood; however, vegan diets (VGNs) do not include animal-origin foods. Typically, US omnivores obtain enough dietary EPA and DHA, but unless VGNs consume algal n-3 supplements, they rely on endogenous production of long-chain fatty acids. VGN diets have several possible concerns: (1) VGNs have high intakes of linoleic acid (LA) as compared to omnivore/non-vegetarian diets. (2) High intakes of LA competitively interfere with the endogenous conversion of alpha-linolenic acid (ALA) to EPA and DHA. (3) High somatic levels of LA/low ALA indicate a decreased ALA conversion to EPA and DHA. (4) Some, not all VGNs meet the Dietary Reference Intake Adequate Intake (DRI-AI) for dietary ALA and (5) VGN diets are high in fiber, which possibly interferes with fat absorption. Consequently, health professionals and Registered Dietitians/Registered Dietitian Nutritionists working with VGNs need specific essential fatty acid diet guidelines. The purpose of this review was: (1) to suggest that VGNs have a DRI-AI Special Consideration requirement for ALA and LA based on VGN dietary and biochemical indicators of status and (2) to provide suggestions to ensure that VGNs receive adequate intakes of LA and ALA.

scholarly journals Long-Chain Omega-3 Polyunsaturated Fatty Acids Have Developmental Effects on the Crop Pest, the Cabbage White Butterfly Pieris rapae

2021 ◽  
Author(s):  
Stefanie M. Hixson ◽  
Kruti Shukla ◽  
Lesley G. Campbell ◽  
Rebecca H. Hallett ◽  
Sandy M. Smith ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Pieris Rapae ◽  
Larval Mortality ◽  
Genetically Engineered ◽  
Pupal Weight ◽  
Omega 3 ◽  
Epa And Dha ◽  
Dha Production ◽  
Long Chain

Nutritional enhancement of crops using genetic engineering can potentially affect herbivorous pests. Recently, oilseed crops have been genetically engineered to produce the long-chain omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) at levels similar to that found in fish oil; to provide a more sustainable source of these compounds than is currently available from wild fish capture. We examined some of the growth and development impacts of adding EPA and DHA to an artificial diet of Pieris rapae, a common pest of Brassicaceae plants. We replaced 1% canola oil with EPA: DHA (11:7 ratio) in larval diets, and examined morphological traits and growth of larvae and ensuing adults across 5 dietary treatments. Diets containing increasing amounts of EPA and DHA did not affect developmental phenology, larval or pupal weight, food consumption, nor larval mortality. However, the addition of EPA and DHA in larval diets resulted in progressively heavier adults (F 4, 108 = 6.78; p = 0.011), with smaller wings (p < 0.05) and a higher frequency of wing deformities (R = 0.988; p = 0.001). We conclude that the presence of EPA and DHA in diets of larval P. rapae may alter adult mass and wing morphology; therefore, further research on the environmental impacts of EPA and DHA production on terrestrial biota is advisable.

scholarly journals Lipid remodeling and an altered membrane-associated proteome may drive the differential effects of EPA and DHA treatment on skeletal muscle glucose uptake and protein accretion

2018 ◽  
Vol 314 (6) ◽  
pp. E605-E619 ◽  
Author(s):  
Stewart Jeromson ◽  
Ivor Mackenzie ◽  
Mary K. Doherty ◽  
Phillip D. Whitfield ◽  
Gordon Bell ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Glucose Uptake ◽  
Long Chain Fatty Acids ◽  
Differential Effects ◽  
Epa And Dha ◽  
Metabolic Remodeling ◽  
The Impact ◽  
Long Chain ◽  
Chain Fatty Acids

In striated muscle, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have differential effects on the metabolism of glucose and differential effects on the metabolism of protein. We have shown that, despite similar incorporation, treatment of C2C12 myotubes (CM) with EPA but not DHA improves glucose uptake and protein accretion. We hypothesized that these differential effects of EPA and DHA may be due to divergent shifts in lipidomic profiles leading to altered proteomic profiles. We therefore carried out an assessment of the impact of treating CM with EPA and DHA on lipidomic and proteomic profiles. Fatty acid methyl esters (FAME) analysis revealed that both EPA and DHA led to similar but substantials changes in fatty acid profiles with the exception of arachidonic acid, which was decreased only by DHA, and docosapentanoic acid (DPA), which was increased only by EPA treatment. Global lipidomic analysis showed that EPA and DHA induced large alterations in the cellular lipid profiles and in particular, the phospholipid classes. Subsequent targeted analysis confirmed that the most differentially regulated species were phosphatidylcholines and phosphatidylethanolamines containing long-chain fatty acids with five (EPA treatment) or six (DHA treatment) double bonds. As these are typically membrane-associated lipid species we hypothesized that these treatments differentially altered the membrane-associated proteome. Stable isotope labeling by amino acids in cell culture (SILAC)-based proteomics of the membrane fraction revealed significant divergence in the effects of EPA and DHA on the membrane-associated proteome. We conclude that the EPA-specific increase in polyunsaturated long-chain fatty acids in the phospholipid fraction is associated with an altered membrane-associated proteome and these may be critical events in the metabolic remodeling induced by EPA treatment.

Multi-scale and multi-system perspectives of zooplankton structure and function in Canadian freshwaters

2021 ◽  
Author(s):  
Bernadette Pinel-Alloul ◽  
Alain Patoine ◽  
Jérôme Marty
Keyword(s):  
Environmental Changes ◽  
Spatial Scales ◽  
Abiotic Factors ◽  
Regional Scale ◽  
Ecological Integrity ◽  
Future Research ◽  
Freshwater Zooplankton ◽  
Anthropogenic Stressors ◽  
Wide Range ◽  
And Function

This review provides a Canadian perspective on freshwater zooplankton diversity and ecology across scales and systems. It aims at describing how zooplankton is a source of biodiversity in forms and functions, a key component of plankton food web, a model for ecological theories and a sentinel for monitoring lake ecological integrity and function facing environmental changes and anthropogenic stressors. These objectives are addressed across a continuum of spatial scales and ecosystem types. Zooplankton communities demonstrated a wide range of responses to anthropogenic disturbances across scales and systems due to interactions with watershed biogeochemistry and climate. This review supports the Multiple Forces hypothesis where forcing by abiotic factors have a primordial role at global scale over Canadian ecoregions, and at regional scale in the Boreal ecozones. In contrast, forcing by biotic factors is more influential at local scale, in resort and urban regions. Future research challenge will be to combine all new concepts and approaches in a holistic perspective to examine the response of freshwater zooplankton to multiple environmental changes and anthropogenic stressors.

scholarly journals Structure and function of the cytochrome P450 peroxygenase enzymes

2018 ◽  
Vol 46 (1) ◽  
pp. 183-196 ◽  
Author(s):  
Andrew W. Munro ◽  
Kirsty J. McLean ◽  
Job L. Grant ◽  
Thomas M. Makris
Keyword(s):  
Fatty Acids ◽  
Cytochromes P450 ◽  
Structural Data ◽  
Short Review ◽  
Biochemical Properties ◽  
Organic Substrates ◽  
Reactive Iron ◽  
Redox Partner ◽  
Wide Range ◽  
And Function

The cytochromes P450 (P450s or CYPs) constitute a large heme enzyme superfamily, members of which catalyze the oxidative transformation of a wide range of organic substrates, and whose functions are crucial to xenobiotic metabolism and steroid transformation in humans and other organisms. The P450 peroxygenases are a subgroup of the P450s that have evolved in microbes to catalyze the oxidative metabolism of fatty acids, using hydrogen peroxide as an oxidant rather than NAD(P)H-driven redox partner systems typical of the vast majority of other characterized P450 enzymes. Early members of the peroxygenase (CYP152) family were shown to catalyze hydroxylation at the α and β carbons of medium-to-long-chain fatty acids. However, more recent studies on other CYP152 family P450s revealed the ability to oxidatively decarboxylate fatty acids, generating terminal alkenes with potential applications as drop-in biofuels. Other research has revealed their capacity to decarboxylate and to desaturate hydroxylated fatty acids to form novel products. Structural data have revealed a common active site motif for the binding of the substrate carboxylate group in the peroxygenases, and mechanistic and transient kinetic analyses have demonstrated the formation of reactive iron-oxo species (compounds I and II) that are ultimately responsible for hydroxylation and decarboxylation of fatty acids, respectively. This short review will focus on the biochemical properties of the P450 peroxygenases and on their biotechnological applications with respect to production of volatile alkenes as biofuels, as well as other fine chemicals.

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