Effect of dietary conjugated linoleic acid (CLA) on metabolism of isotope-labeled oleic, linoleic, and CLA isomers in women
| Autor: | S. Duval, Gary J. Nelson, P. Benito, E. A. Emken, R. O. Adlof |
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| Rok vydání: | 2002 |
| Předmět: |
Adult
Time Factors food.ingredient Clinical chemistry Conjugated linoleic acid Metabolite Biochemistry Linoleic Acid chemistry.chemical_compound food Dietary Fats Unsaturated Isomerism Structural isomer Humans Food science Cholesterol Sunflower oil Organic Chemistry Cell Biology Metabolism Deuterium Lipids chemistry Area Under Curve Female lipids (amino acids peptides and proteins) Adsorption Oleic Acid Lipidology |
| Zdroj: | Lipids. 37:741-750 |
| ISSN: | 1558-9307 0024-4201 |
| Popis: | The purpose of this study was to investigate the effect of dietary CLA on accretion of 9c-18∶1, 9c, 12c-18∶2, 10t, 12c-18∶2, and 9c, 11t-18∶2 and conversion of these FA to their desaturated, elongated, and chain-shortened metabolites. The subjects were six healthy adult women who had consumed normal diets supplemented with 6 g/d of sunflower oil or 3.9 g/d of CLA for 63 d. A mixture of 10t, 12c-18∶2-d 4, 9c, 11t-18∶2-d 6, 9c-18∶1-d 8, and 9c, 12c-18∶2-d 2, as their ethyl esters, was fed to each subject, and nine blood samples were drawn over a 48-h period. The results show that dietary CLA supplementation had no effect on the metabolism of the deuterium-labeled FA. These metabolic results were consistent with the general lack of a CLA diet effect on a variety of physiological responses previously reported for these women. The 2H-CLA isomers were metabolically different. The relative percent differences between the accumulation of 9c, 11t-18∶2-d 6 and 10t, 12c-18∶2-d 4 in plasma lipid classes ranged from 9 to 73%. The largest differences were a fourfold higher incorporation of 10t, 12c-18∶2-d 4 than 9c, 11t-18∶2-d 6 in 1-acyl PC and a two- to threefold higher incorporation of 9c, 11t-18∶2-d 6 than 10t, 12c-18∶2-d 4 in cholesterol esters. Compared to 9c-18∶1-d 8 and 9c, 12c-18∶2-d 2, the 10t, 12c-18∶2-d 4 and 9c, 11t-18∶2-d 6 isomers were 20–25% less well absorbed. Relative to 9c-18∶1, incorporation of the CLA isomers into 2-acyl PC and cholesterol ester was 39–84% lower and incorporation of 10t, 12c-18∶2 was 50% higher in 1-acyl PC. This pattern of selective incorporation and discrimination is similar to the pattern generally observed for trans and cis 18∶1 positional isomers. Elongated and desaturated CLA metabolites were detected. The concentration of 6c, 10t, 12c-18∶3-d 4 in plasma TG was equal to 6.8% of the 10t, 12c-18∶2-d 4 present, and TG was the only lipid fraction that contained a CLA metabolite present at concentrations sufficient for reliable quantification. In conclusion, no effect of dietary CLA was observed, absorption of CLA was less than that of 9c-18∶1, CLA positional isomers were metabolically different, and conversion of CLA isomers to desaturated and elongated metabolites was low. |
| Databáze: | OpenAIRE |
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