scholarly journals Hepatic de novo lipogenesis is suppressed and fat oxidation is increased by omega-3 fatty acids at the expense of glucose metabolism

2019 ◽  
Author(s):  
Charlotte Green ◽  
Camilla Pramfalk ◽  
Catriona Charlton ◽  
Pippa Gunn ◽  
Thomas Cornfield ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Glucose Metabolism ◽  
De Novo ◽  
Fat Oxidation ◽  
De Novo Lipogenesis ◽  
Omega 3 Fatty Acids ◽  
Omega 3

scholarly journals Hepatic de novo lipogenesis is suppressed and fat oxidation is increased by omega-3 fatty acids at the expense of glucose metabolism

2020 ◽  
Vol 8 (1) ◽  
pp. e000871 ◽  
Author(s):  
Charlotte J Green ◽  
Camilla Pramfalk ◽  
Catriona A Charlton ◽  
Pippa J Gunn ◽  
Thomas Cornfield ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Plasma Glucose ◽  
De Novo ◽  
In Vitro Studies ◽  
De Novo Lipogenesis ◽  
Metabolic Effects ◽  
Omega 3 Fatty Acids ◽  
Omega 3

ObjectiveIncreased hepatic de novo lipogenesis (DNL) is suggested to be an underlying cause in the development of nonalcoholic fatty liver disease and/or insulin resistance. It is suggested that omega-3 fatty acids (FA) lower hepatic DNL. We investigated the effects of omega-3 FA supplementation on hepatic DNL and FA oxidation using a combination of human in vivo and in vitro studies.Research design and methodsThirty-eight healthy men were randomized to take either an omega-3 supplement (4 g/day eicosapentaenoic acid (EPA)+docosahexaenoic acid (DHA) as ethyl esters) or placebo (4 g/day olive oil) and fasting measurements were made at baseline and 8 weeks. The metabolic effects of omega-3 FAs on intrahepatocellular triacylglycerol (IHTAG) content, hepatic DNL and FA oxidation were investigated using metabolic substrates labeled with stable-isotope tracers. In vitro studies, using a human liver cell-line was undertaken to gain insight into the intrahepatocellular effects of omega-3 FAs.ResultsFasting plasma TAG concentrations significantly decreased in the omega-3 group and remained unchanged in the placebo group. Eight weeks of omega-3 supplementation significantly decreased IHTAG, fasting and postprandial hepatic DNL while significantly increasing dietary FA oxidation and fasting and postprandial plasma glucose concentrations. In vitro studies supported the in vivo findings of omega-3 FAs (EPA+DHA) decreasing intracellular TAG through a shift in cellular metabolism away from FA esterification toward oxidation.ConclusionsOmega-3 supplementation had a potent effect on decreasing hepatic DNL and increasing FA oxidation and plasma glucose concentrations. Attenuation of hepatic DNL may be considered advantageous; however, consideration is required as to what the potential excess of nonlipid substrates (eg, glucose) will have on intrahepatic and extrahepatic metabolic pathways.Trial registration numberNCT01936779.

scholarly journals Blood n-3 fatty acid levels and total and cause-specific mortality from 17 prospective studies

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
William S. Harris ◽  
◽  
Nathan L. Tintle ◽  
Fumiaki Imamura ◽  
Frank Qian ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
De Novo ◽  
Premature Death ◽  
Pooled Analysis ◽  
Omega 3 Fatty Acids ◽  
Omega 3 ◽  
Alpha Linolenic Acid ◽  
Omega 3 Fatty Acid

AbstractThe health effects of omega-3 fatty acids have been controversial. Here we report the results of a de novo pooled analysis conducted with data from 17 prospective cohort studies examining the associations between blood omega-3 fatty acid levels and risk for all-cause mortality. Over a median of 16 years of follow-up, 15,720 deaths occurred among 42,466 individuals. We found that, after multivariable adjustment for relevant risk factors, risk for death from all causes was significantly lower (by 15–18%, at least p < 0.003) in the highest vs the lowest quintile for circulating long chain (20–22 carbon) omega-3 fatty acids (eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids). Similar relationships were seen for death from cardiovascular disease, cancer and other causes. No associations were seen with the 18-carbon omega-3, alpha-linolenic acid. These findings suggest that higher circulating levels of marine n-3 PUFA are associated with a lower risk of premature death.

Model for measuring absolute rates of hepatic de novo lipogenesis and reesterification of free fatty acids

1993 ◽  
Vol 265 (5) ◽  
pp. E814-E820 ◽  
Author(s):  
M. K. Hellerstein ◽  
R. A. Neese ◽  
J. M. Schwarz
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
De Novo ◽  
Human Subjects ◽  
Fat Oxidation ◽  
De Novo Lipogenesis ◽  
Whole Body ◽  
Distribution Analysis ◽  
Oxidation Rates ◽  
Mass Isotopomer Distribution Analysis

We have previously presented a precursor-product stable isotopic technique for measuring in vivo the fraction of very low-density lipoprotein-fatty acids (VLDL-FA) derived from de novo lipogenesis (fractional DNL). Here, we propose a technique for converting fractional DNL into absolute rates of DNL and describe its explicit underlying assumptions. The technique combines the fractional DNL method with a modification of the method of S. Klein, V. R. Young, G. L. A. Blackburn, B. R. Bistrain, and R. R. Wolfe (J. Clin. Invest. 78: 928-933, 1986), for estimating hepatic reesterification of free fatty acids (FFA). Infusions of [1,2,3,4-13C]palmitate and [1-13C]acetate are performed concurrently with indirect calorimetry in human subjects. Fractional DNL (based on mass isotopomer distribution analysis of VLDL-FA), the rate of appearance of plasma FFA (Ra of FFA), and net fat oxidation in the whole body are measured. Equations from the hepatic reesterification model, modified to include the contribution from DNL, allow calculation of absolute DNL (= fractional DNL x [Ra of FFA - net whole body fat oxidation], when respiratory quotient < 1.0). Sample results from human subjects with different dietary energy intakes are presented, with calculations of absolute DNL, absolute reesterification, and absolute fat oxidation rates. The assumptions of this technique (in particular, that all fat oxidized is derived at steady state from circulating FFA and that DNL and reesterification of FFA both occur exclusively in liver) are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The Use of Omega-3 Fatty Acids in Mental Illness

2011 ◽  
Vol 24 (5) ◽  
pp. 452-471 ◽  
Author(s):  
Jessica L. Gören ◽  
Ashley T. Tewksbury
Keyword(s):  
Fatty Acids ◽  
Mental Illness ◽  
De Novo ◽  
The Body ◽  
Mental Illnesses ◽  
Current Evidence ◽  
Omega 3 Fatty Acids ◽  
Omega 3 ◽  
Medline Search ◽  
Omega 6

Purpose: This article will summarize the current evidence on the effects of omega-3 fatty acids on prevention and treatment of mental illness. Background: Omega-3 fatty acids are involved in many physiologic processes. Since they cannot be made de novo in the body, they are considered essential nutrients. As the Western diet evolved, dietary intake of fatty acids has shifted to increased omega-6 fatty acids and decreased omega-3 fatty acids intake. These changes have been correlated with numerous differences in prevalence and course of mental illnesses. Methods: A MEDLINE search from 1966 to December 2010 was completed to identify studies comparing changes in symptoms, functioning, other outcomes, and/or side effects in patients treated with omega-3 fatty acids for mental illness. The studies were reviewed and reported by specific psychiatric disorder studied. Conclusions: Omega-3 fatty acids play a role in many biologic functions. Epidemiologic data implicate omega-3 fatty acid deficiencies in many mental illnesses. Data are most robust for omega-3 fatty acids' role in affective disorders. However, data are conflicting, negative, or absent for most mental illnesses.

scholarly journals Novel Vibrio spp. Strains Producing Omega-3 Fatty Acids Isolated from Coastal Seawater

Marine Drugs ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 99 ◽  
Author(s):  
Mónica Estupiñán ◽  
Igor Hernández ◽  
Eduardo Saitua ◽  
M. Elisabete Bilbao ◽  
Iñaki Mendibil ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Gene Cluster ◽  
De Novo ◽  
Saturated Fatty Acids ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Omega 3 Fatty Acids ◽  
Omega 3 ◽  
Coastal Seawater

Omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs), such as eicosapentaenoic acid (EPA) (20:5n-3) and docosahexaenoic acid (DHA) (22:6n-3), are considered essential for human health. Microorganisms are the primary producers of omega-3 fatty acids in marine ecosystems, representing a sustainable source of these lipids, as an alternative to the fish industry. Some marine bacteria can produce LC-PUFAs de novo via the Polyunsaturated Fatty Acid (Pfa) synthase/ Polyketide Synthase (PKS) pathway, which does not require desaturation and elongation of saturated fatty acids. Cultivation-independent surveys have revealed that the diversity of microorganisms harboring a molecular marker of the pfa gene cluster (i.e., pfaA-KS domain) is high and their potential distribution in marine systems is widespread, from surface seawater to sediments. However, the isolation of PUFA producers from marine waters has been typically restricted to deep or cold environments. Here, we report a phenotypic and genotypic screening for the identification of omega-3 fatty acid producers in free-living bacterial strains isolated from 5, 500, and 1000 m deep coastal seawater from the Bay of Biscay (Spain). We further measured EPA production in pelagic Vibrio sp. strains collected at the three different depths. Vibrio sp. EPA-producers and non-producers were simultaneously isolated from the same water samples and shared a high percentage of identity in their 16S rRNA genes, supporting the view that the pfa gene cluster can be horizontally transferred. Within a cluster of EPA-producers, we found intraspecific variation in the levels of EPA synthesis for isolates harboring different genetic variants of the pfaA-KS domain. The maximum production of EPA was found in a Vibrio sp. strain isolated from a 1000 m depth (average 4.29% ± 1.07 of total fatty acids at 10 °C, without any optimization of culturing conditions).

Fish oil plus wheat germ oil have no prominent effect on homocysteine levels and nutritional indices in hemodialysis patients

2019 ◽  
pp. 1-7
Author(s):  
Hadeer Zakaria ◽  
Tarek M. Mostafa ◽  
Gamal A. El-Azab ◽  
Nagy AH Sayed-Ahmed
Keyword(s):  
Fatty Acids ◽  
Vitamin E ◽  
Fish Oil ◽  
Wheat Germ ◽  
Hemodialysis Patients ◽  
Nutritional Indices ◽  
Omega 3 Fatty Acids ◽  
Omega 3 ◽  
Wheat Germ Oil ◽  
Serum Homocysteine

Abstract. Background: Elevated homocysteine levels and malnutrition are frequently detected in hemodialysis patients and are believed to exacerbate cardiovascular comorbidities. Omega-3 fatty acids have been postulated to lower homocysteine levels by up-regulating metabolic enzymes and improving substrate availability for homocysteine degradation. Additionally, it has been suggested that prevention of folate depletion by vitamin E consumption decreases homocysteine levels. However, data on the effect of omega-3 fatty acids and/or vitamin E on homocysteine levels and nutritional status have been inconclusive. Therefore, this study was planned to examine the effect of combined supplementation of fish oil, as a source of omega-3 fatty acids, with wheat germ oil, as a source of vitamin E, on homocysteine and nutritional indices in hemodialysis patients. Methods: This study was a randomized, double-blind, placebo-controlled trial. Forty-six hemodialysis patients were randomly assigned to two equally-sized groups; a supplemented group who received 3000 mg/day of fish oil [1053 mg omega-3 fatty acids] plus 300 mg/day of wheat germ oil [0.765 mg vitamin E], and a matched placebo group who received placebo capsules for 4 months. Serum homocysteine and different nutritional indices were measured before and after the intervention. Results: Twenty patients in each group completed the study. At the end of the study, there were no significant changes in homocysteine levels and in the nutritional indices neither in the supplemented nor in the placebo-control groups (p > 0.05). Conclusions: Fish oil and wheat germ oil combination did not produce significant effects on serum homocysteine levels and nutritional indices of hemodialysis patients.

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