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The American Journal of Clinical... Jun 2014Plasma phospholipid concentrations of trans-palmitoleic acid (trans-16:1n-7), a biomarker of dairy fat intake, are inversely associated with incident type 2 diabetes in... (Observational Study)
Observational Study
BACKGROUND
Plasma phospholipid concentrations of trans-palmitoleic acid (trans-16:1n-7), a biomarker of dairy fat intake, are inversely associated with incident type 2 diabetes in 2 US cohorts.
OBJECTIVE
The objective was to investigate whether the intake of trans-16:1n-7 in particular, or dairy fat in general, is associated with glucose tolerance and key factors determining glucose tolerance.
DESIGN
A cross-sectional investigation was undertaken in 17 men and women with nonalcoholic fatty liver disease and 15 body mass index (BMI)- and age-matched controls. The concentrations of trans-16:1n-7 and 2 other biomarkers of dairy fat intake, 15:0 and 17:0, were measured in plasma phospholipids and free fatty acids (FFAs). Liver fat was estimated by computed tomography-derived liver-spleen ratio. Intravenous-glucose-tolerance tests and oral-glucose-tolerance test (OGTT) and hyperinsulinemic-euglycemic clamps were performed to assess β-cell function and hepatic and systemic insulin sensitivity.
RESULTS
In multivariate analyses adjusted for age, sex, and BMI, phospholipid 17:0, phospholipid trans-16:1n-7, FFA 15:0, and FFA 17:0 were inversely associated with fasting plasma glucose, the area under the curve for glucose during an OGTT, and liver fat. Phospholipid trans-16:1n-7 was also positively associated with hepatic and systemic insulin sensitivity. None of the biomarkers were associated with β-cell function. The associations between dairy fat intake and glucose tolerance were attenuated by adjusting for insulin sensitivity or liver fat, but strengthened by adjusting for β-cell function.
CONCLUSION
Although we cannot rule out reverse causation, these data support the hypothesis that dairy fat improves glucose tolerance, possibly through a mechanism involving improved hepatic and systemic insulin sensitivity and reduced liver fat.
Topics: Adult; Biomarkers; Case-Control Studies; Cohort Studies; Cross-Sectional Studies; Dairy Products; Dietary Fats; Fatty Acids; Fatty Acids, Monounsaturated; Female; Humans; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Lipid Metabolism; Liver; Male; Middle Aged; Non-alcoholic Fatty Liver Disease; Tomography, X-Ray Computed; Trans Fatty Acids
PubMed: 24740208
DOI: 10.3945/ajcn.113.075457 -
American Journal of Physiology.... Jul 2016Classical brown adipocytes such as those found in interscapular brown adipose tissue (iBAT) represent energy-burning cells, which have been postulated to play a pivotal...
Classical brown adipocytes such as those found in interscapular brown adipose tissue (iBAT) represent energy-burning cells, which have been postulated to play a pivotal role in energy metabolism. Brown adipocytes can also be found in white adipose tissue (WAT) depots [e.g., inguinal WAT (iWAT)] following adrenergic stimulation, and they have been referred to as "beige" adipocytes. Whether the presence of these adipocytes, which gives iWAT a beige appearance, can confer a white depot with some thermogenic activity remains to be seen. In consequence, we designed the present study to investigate the metabolic activity of iBAT, iWAT, and epididymal white depots in mice. Mice were either 1) kept at thermoneutrality (30°C), 2) kept at 30°C and treated daily for 14 days with an adrenergic agonist [CL-316,243 (CL)], or 3) housed at 10°C for 14 days. Metabolic activity was assessed using positron emission tomography imaging with fluoro-[(18)F]deoxyglucose (glucose uptake), fluoro-[(18)F]thiaheptadecanoic acid (fatty acid uptake), and [(11)C]acetate (oxidative activity). In each group, substrate uptakes and oxidative activity were measured in anesthetized mice in response to acute CL. Our results revealed iBAT as a major site of metabolic activity, which exhibited enhanced glucose and nonesterified fatty acid uptakes and oxidative activity in response to chronic cold and CL. On the other hand, beige adipose tissue failed to exhibit appreciable increase in oxidative activity in response to chronic cold and CL. Altogether, our results suggest that the contribution of beige fat to acute-CL-induced metabolic activity is low compared with that of iBAT, even after sustained adrenergic stimulation.
Topics: Acetates; Adipose Tissue, Beige; Adipose Tissue, Brown; Adipose Tissue, White; Adrenergic beta-3 Receptor Agonists; Animals; Carbon Radioisotopes; Cold Temperature; Dioxoles; Fatty Acids; Fluorodeoxyglucose F18; Male; Mice; Positron-Emission Tomography; Radiopharmaceuticals
PubMed: 27143559
DOI: 10.1152/ajpendo.00545.2015 -
The Biochemical Journal Jan 1957
Topics: Fatty Acids; Food
PubMed: 13403863
DOI: 10.1042/bj0650018 -
International Journal of Molecular... Jan 2020The transition from pregnancy to lactation is characterized by a progressive decrease in insulin sensitivity. Propionate increases with dietary fiber consumption and has...
Inclusion of Soluble Fiber in the Gestation Diet Changes the Gut Microbiota, Affects Plasma Propionate and Odd-Chain Fatty Acids Levels, and Improves Insulin Sensitivity in Sows.
The transition from pregnancy to lactation is characterized by a progressive decrease in insulin sensitivity. Propionate increases with dietary fiber consumption and has been shown to improve insulin sensitivity. Recent studies suggest that plasma odd-chain fatty acids [OCFAs; pentadecanoic acid (C15:0) and heptadecanoic acid (C17:0)] that inversely correlated with insulin resistance are synthesized endogenously from gut-derived propionate. The present study investigated the effects of soluble fiber during gestation on gut microbiota, plasma non-esterified fatty acids and insulin sensitivity in sows. Sows were allocated to either control or 2.0% guar gum plus pregelatinized waxy maize starch (SF) dietary treatment during gestation. The SF addition changes the structure and composition of gut microbiota in sows. Genus increased by SF addition may promote intestinal propionate production. Moreover, the dietary SF increased circulating levels of plasma OCFAs, especially C17:0. The SF-fed sows had a higher insulin sensitivity and a lower systemic inflammation level during perinatal period. Furthermore, the plasma C15:0 and C17:0 was negatively correlated with the area under curve of plasma glucose after meal and plasma interleukin-6. In conclusion, dietary SF improves insulin sensitivity and alleviates systemic inflammation in perinatal sows, potentially related to its stimulating effect on propionate and OCFAs production.
Topics: Animal Nutritional Physiological Phenomena; Animals; Dietary Fiber; Eubacterium; Fatty Acids; Female; Galactans; Gastrointestinal Microbiome; Gelatin; Insulin Resistance; Intestines; Mannans; Plant Gums; Pregnancy; Propionates; Swine
PubMed: 31963640
DOI: 10.3390/ijms21020635 -
Nutrition Journal Apr 2014Dairy food is an important natural source of saturated and trans fatty acids in the human diet. This study evaluates the effect of dietary advice to change dairy food... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Dairy food is an important natural source of saturated and trans fatty acids in the human diet. This study evaluates the effect of dietary advice to change dairy food intake on plasma fatty acid levels known to be present in milk in healthy volunteers.
METHODS
Twenty one samples of whole fat dairy milk were analyzed for fatty acids levels. Changes in levels of plasma phospholipid levels were evaluated in 180 healthy volunteers randomized to increase, not change or reduce dairy intake for one month. Fatty acids were measured by gas chromatography-mass spectrometry and levels are normalized to d-4 alanine.
RESULTS
The long chain fatty acids palmitic (13.4%), stearic (16.7%) and myristic (18.9%) acid were most common saturated fats in milk. Four trans fatty acids constituted 3.7% of the total milk fat content. Increased dairy food intake by 3.0 (± 1.2) serves/ day for 1 month was associated with small increases in plasma levels of myristic (+0.05, 95% confidence level-0.08 to 0.13, p = 0.07), pentadecanoic (+0.014, 95% confidence level -0.016 to 0.048, p = 0.02) and margaric acid (+0.02, -0.03 to 0.05, p = 0.03). There was no significant change in plasma levels of 4 saturated, 4 trans and 10 unsaturated fatty acids. Decreasing dairy food intake by 2.5 (± 1.2) serves per day was not associated with change in levels of any plasma fatty acid levels.
CONCLUSION
Dietary advice to change dairy food has a minor effect on plasma fatty acid levels.
TRIAL REGISTRATION
ACTRN12612000574842.
Topics: Adult; Animals; Cardiovascular Diseases; Dairy Products; Dietary Fats; Fatty Acids; Fatty Acids, Unsaturated; Female; Humans; Male; Middle Aged; Milk; Phospholipids; Trans Fatty Acids
PubMed: 24708591
DOI: 10.1186/1475-2891-13-32 -
Journal of Biochemistry Jan 1982The product distribution of Brevibacterium ammoniagenes fatty acid synthetase has been investigated using propionyl-CoA instead of acetyl-CoA as the primer. The...
The product distribution of Brevibacterium ammoniagenes fatty acid synthetase has been investigated using propionyl-CoA instead of acetyl-CoA as the primer. The synthetase produces not only an odd-numbered fatty acid (heptadecanoic acid) but also even-numbered fatty acids (stearic and oleic acids) in the presence of propionyl-CoA. The amounts of heptadecanoic, stearic and oleic acids increased with increasing concentration of propionyl-CoA. However, the formation of heptadecenoic acid (C17:1) was not observed under any conditions tested. The failure of C17:1 synthesis suggested that the enzyme component catalyzing the beta, gamma-dehydration, which is responsible for the synthesis of unsaturated fatty acids, has a high degree of chain length specificity. Under standard assay conditions, stearic acid predominated and heptadecanoic and oleic acids were found in lesser amounts. Mass spectrometric analyses of fatty acids synthesized either from [2H]propionyl-CoA or in 2H2O revealed that propionyl-CoA is utilized as the priming substrate for the synthesis of heptadecanoic acid and that an acetyl residues, which is formed by the decarboxylation of malonyl-CoA, served as the priming substrate for the syntheses of stearic and oleic acids. No evidence was obtained for the direct decarboxylation of malonyl-CoA to acetyl-CoA in this reaction. It is concluded that the decarboxylation of the malonyl moiety bound to the synthetase occurs efficiently only in the course of fatty acid synthesis. A hypothetical scheme is presented to explain the propionyl-CoA-dependent decarboxylation of the malonyl moiety.
Topics: Acetyl Coenzyme A; Acyl Coenzyme A; Brevibacterium; Chemical Phenomena; Chemistry; Deuterium; Fatty Acid Synthases; Fatty Acids; Malonyl Coenzyme A; Oleic Acids; Stearic Acids; Substrate Specificity
PubMed: 7068555
DOI: 10.1093/oxfordjournals.jbchem.a133667 -
Journal of Nuclear Medicine : Official... Jan 19881-[11C]-3,3-dimethylheptadecanoic acid [( 11C]DMHDA) has been prepared for evaluation as a potential myocardial metabolism indicator based on an expected intrinsic...
1-[11C]-3,3-dimethylheptadecanoic acid [( 11C]DMHDA) has been prepared for evaluation as a potential myocardial metabolism indicator based on an expected intrinsic stability toward beta-oxidative metabolic processes. Synthesis of this novel branched-chain fatty acid was accomplished by copper-catalyzed addition of tetradecylmagnesium bromide to diethylisopropylidenemalonate. Subsequent saponification and decarboxylation afforded 3,3-dimethylheptadecanoic acid (DMHDA) that was converted to the corresponding alkyl bromide by means of a modified Hunsdiecker reaction. Carboxylation of 2,2-dimethylhexadecylmagnesium bromide with 11CO2 gave [11C]DMHDA. Carbon-11 DMHDA showed moderate myocardial uptake in fasted rats, albeit lower than that reported for the 3-monomethyl analog. Considerable washout of radioactivity from the heart was also observed over the first 30 min postinjection. Imaging in dogs likewise showed disappointing heart uptake with much higher localization in the lung. These data suggest that gem-dimethyl substitution of the beta-position in long chain fatty acids is not only insufficient for enhanced myocardial uptake and retention, but also, may be deleterious when compared with beta-monomethylation.
Topics: Animals; Carbon Radioisotopes; Dogs; Fatty Acids; Heart; Radionuclide Imaging; Rats; Tissue Distribution
PubMed: 3335930
DOI: No ID Found -
The British Journal of Nutrition Apr 2004Milk fat is high in saturated fatty acids (SFA) and high intakes of SFA are associated with cardiovascular diseases. The aim of the present study was to prospectively...
Estimated intake of milk fat is negatively associated with cardiovascular risk factors and does not increase the risk of a first acute myocardial infarction. A prospective case-control study.
Milk fat is high in saturated fatty acids (SFA) and high intakes of SFA are associated with cardiovascular diseases. The aim of the present study was to prospectively evaluate the potential risk of a first-ever acute myocardial infarction (AMI) in relation to the estimated milk-fat intake, reflected as the proportions of pentadecanoic acid (15 : 0) and heptadecanoic acid (17 : 0) in serum lipid esters. This was evaluated in a study population selected within the Västerbotten Intervention Program and the northern Sweden 'Monitoring of Trends and Determinants in Cardiovascular disease' survey populations. A prospective case-control design was used. The proportions of the biomarkers were lower in the cases (n 78) than in the controls (n 156), who were matched for age, sex, sampling time and geographical region. The standardised odds ratios of becoming an AMI case were between 0.7 and 0.8 for the biomarkers. The proportions of 15 : 0 and 17 : 0 in serum phospholipids were significantly and negatively correlated to serum concentrations of plasminogen activator inhibitor-1, tissue-type plasminogen activator, triacylglycerols, insulin, specific insulin, pro-insulin and leptin (all P<0.0001), suggesting a negative relationship to the insulin-resistance syndrome and the risk of CHD. Adjustment for BMI did not materially change the relationships. Although there seems to be a negative association between milk-fat intake as mirrored by the proportions of 15 : 0 and 17 : 0 in serum lipid esters and a first-ever AMI, adjustment for clinical risk factors removed this relationship.
Topics: Adult; Aged; Animals; Biomarkers; Case-Control Studies; Diet; Dietary Fats; Fatty Acids; Female; Humans; Lipids; Logistic Models; Male; Middle Aged; Milk; Myocardial Infarction; Prospective Studies; Risk Factors
PubMed: 15035691
DOI: 10.1079/BJN20041080 -
Journal of Lipid Research May 1993This paper appraises an HPLC method for assaying phospholipase A2 (PLA2). The procedure is based on heptane-isopropanol-H2SO4 extraction of fatty acids released by the... (Comparative Study)
Comparative Study
This paper appraises an HPLC method for assaying phospholipase A2 (PLA2). The procedure is based on heptane-isopropanol-H2SO4 extraction of fatty acids released by the enzyme in the presence of margaric acid as an internal standard, and precolumn derivatization with 9-anthryldiazomethane. The derivatives of naturally occurring long-chain fatty acids were accurately determined by reverse-phase HPLC with ultraviolet detection at 254 nm; the fatty acids were identical with margaric acid in terms of their extraction efficiency in the presence or absence of a bile salt, reactivity with the labeling reagent, and molar extinction coefficients of their derivatives. HPLC conditions were optimized so as to separate the derivatives of palmitic and oleic acids completely within 7 min. The use of the 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol/cholate system as substrate proved useful for the sensitive detection of PLA2 activities in rat tissue homogenates. Distribution of immunoreactive pancreatic and group II phospholipases A2 was estimated from the degree of inhibition of enzyme activities by specific antibodies raised against either forms of phospholipase A2 isozymes. The results were consistent with those of immunoblot analyses.
Topics: Animals; Anthracenes; Blotting, Western; Calcium; Chromatography, High Pressure Liquid; Fatty Acids; Isoenzymes; Phosphatidylethanolamines; Phospholipases A; Phospholipases A2; Rats; Spectrophotometry, Ultraviolet; Tissue Distribution
PubMed: 8509721
DOI: No ID Found -
Research in Microbiology Aug 2005Molecular methods were used to characterize stearate- and heptadecanoate-degrading methanogenic consortia enriched from a low-temperature biodegraded oil field....
Molecular methods were used to characterize stearate- and heptadecanoate-degrading methanogenic consortia enriched from a low-temperature biodegraded oil field. Stearate- and heptadecanoate-degrading cultures formed acetate. Growth on heptadecanoate was also accompanied by the production of propionate. These fermentation products were transiently accumulated at the beginning of the exponential phase and were further consumed with the concomitant production of methane. Clone libraries of bacterial and archaeal 16S rRNA genes were generated for each stable enrichment. Our 16S rRNA gene-cloning analysis combined with fluorescence in situ hybridization revealed that the predominant microorganisms in the associations were affiliated with a clone cluster close to the genus Syntrophus in the class "Deltaproteobacteria" and with the methanogenic genera Methanocalculus and Methanosaeta. Confocal scanning laser microscopy showed that the bacterial and archaeal cells formed compact aggregates around the insoluble substrates. No layered structure was observed in the aggregate organization. This study reports the presence of new fatty-acid-degrading syntrophic consortia in oil fields and our results suggest that such associations may have an important ecological role in oil fields under methanogenic conditions.
Topics: Acetic Acid; Biodegradation, Environmental; DNA, Archaeal; DNA, Bacterial; DNA, Ribosomal; Deltaproteobacteria; Ecosystem; Euryarchaeota; Fatty Acids; In Situ Hybridization, Fluorescence; Methane; Methanomicrobiales; Methanosarcinales; Microscopy, Confocal; Molecular Sequence Data; Petroleum; Phylogeny; Propionates; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Soil Microbiology; Stearates
PubMed: 15939576
DOI: 10.1016/j.resmic.2005.03.009