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" Effect of omega-3 fatty acids on t10, c12-conjugated linoleic acid induced insulin resistance, non alcoholic fatty liver disease and tissue fatty acid composition "
Madhuri Vemuri
D. S. Kelley
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Latin Dissertation
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| Language of Document
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English
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| Record Number
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55405
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TL25359
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| Call number
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3396890
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| Main Entry
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Madhuri Vemuri
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| Title & Author
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Effect of omega-3 fatty acids on t10, c12-conjugated linoleic acid induced insulin resistance, non alcoholic fatty liver disease and tissue fatty acid composition\ Madhuri Vemuri
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| College
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University of California, Davis
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| Date
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2009
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| Degree
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Ph.D.
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2009
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| Page No
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164
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| Abstract
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Conjugated linoleic acid (CLA) refers to all the positional and geometric isomers of linoleic acid. The two most studied isomers are cis 9, trans 11-CLA and trans 10, cis 12-CLA. CLA supplements, often a mixture of the two isomers, have been popularly used for weight loss and other claimed health benefits. However supplementing CLA isomers, especially trans 10, cis 12-CLA has been shown to cause non alcoholic fatty liver disease (NAFLD) and insulin resistance (IR) in several animal models. Here we have confirmed that supplementing 0.5% trans 10, cis 12-CLA to C57BL/6 mice for 8 weeks causes NAFLD and IR. When CLA diets were concomitantly supplemented with omega-3 fatty acids docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) at 1.5% (w/w) for 8 weeks, DHA prevented CLA induced IR, while EPA was ineffective. Both EPA and DHA prevented CLA induced fatty liver. CLA also reduced the plasma leptin and adiponectin concentrations, and both EPA and DHA partially restored plasma leptin, but only DHA partially restored the plasma adiponectin. In another experiment, concomitant supplementation of CLA diets with 0.5% of flaxseed oil (rich in alpha linolenic acid) also prevented IR and decreased liver weights and lipids compared with those in CLA group. CLA supplementation also altered lipid profile in liver, decreasing n -6 and n -3 wt% and increasing n -6:n -3 ratio. Concomitant supplementation with flaxseed oil increased n -6 and n -3 polyunsaturated (PUFA) in liver lipids and decreased the n -6:n -3 ratio compared to that in CLA group. Supplementing 0.5% (w/w) of purified c9, t11- or trans 10, cis 12-CLA to mice for 8 weeks altered fatty acid profile of tissues differently. c 9, t 11-CLA diet reduced MUFA wt% in liver, adipose tissue, and spleen, and reduced the spleen n-3 PUFAs significantly while increasing the n-6 PUFA wt% in all tissues except heart. In contrast, trans 10, cis 12-CLA reduced both the n-6 and n-3 PUFA wt% in liver and heart however increased the wt% of n-3 PUFAs in spleen. Considering the adverse health effects of trans 10, cis 12-CLA and of mixtures of CLA isomers on NAFLD, IR and tissue fatty acids, human use of CLA supplements should not be recommended.
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| Subject
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Health and environmental sciences; Conjugated linoleic acid; Insulin resistance; Nonalcoholic fatty liver disease; Omega-3 fatty acids; Nutrition; 0570:Nutrition
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D. S. Kelley
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University of California, Davis
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