Cited by 292Fatty Acid Research and HealthAntioxidant Activity and Oxidative StressAdipokines, Inflammation, and Metabolic Diseases

Supplementation With Conjugated Linoleic Acid Causes Isomer-Dependent Oxidative Stress and Elevated C-Reactive Protein: A Potential Link to Fatty Acid-Induced Insulin Resistance

Risérus, Ulf, Basu, Samar, Jovinge, Stefan, Fredrikson, Gunilla Nordin, Ärnlöv, Johan, Vessby, Bengt·2002·Circulation

Abstract

BACKGROUND: Conjugated linoleic acids (CLAs), a group of fatty acids shown to have beneficial effects in animals, are also used as weight loss supplements. Recently, we reported that the t10c12 CLA-isomer caused insulin resistance in abdominally obese men via unknown mechanisms. The aim of the present study was to examine whether CLA has isomer-specific effects on oxidative stress or inflammatory biomarkers and to investigate the relationship between these factors and induced insulin resistance. METHODS AND RESULTS: In a double-blind placebo-controlled trial, 60 men with metabolic syndrome were randomized to one of 3 groups receiving t10c12 CLA, a CLA mixture, or placebo for 12 weeks. Insulin sensitivity (euglycemic clamp), serum lipids, in vivo lipid peroxidation (determined as urinary 8-iso-PGF(2alpha) [F2-isoprostanes]), 15-ketodihydro PGF(2alpha), plasma vitamin E, plasma C-reactive protein, tumor necrosis factor-alpha, and interleukin-6 were assessed before and after treatment. Supplementation with t10c12 CLA markedly increased 8-iso-PGF(2alpha) (578%) and C-reactive protein (110%) compared with placebo (P<0.0001 and P<0.01, respectively) and independent of changes in hyperglycemia or dyslipidemia. The increases in 8-iso-PGF(2alpha), but not in C-reactive protein, were significantly and independently related to aggravated insulin resistance. Oxidative stress was related to increased vitamin E levels, suggesting a compensatory mechanism. CONCLUSIONS: t10c12 CLA supplementation increases oxidative stress and inflammatory biomarkers in obese men. The oxidative stress seems closely related to induced insulin resistance, suggesting a link between the fatty acid-induced lipid peroxidation seen in the present study and insulin resistance. These unfavorable effects of t10c12 CLA might be of clinical importance with regard to cardiovascular disease, in consideration of the widespread use of dietary supplements containing this fatty acid.

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Crossref · 10.1161/01.cir.0000033589.15413.48

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Authors
Risérus, U., Basu, S., Jovinge, S., Fredrikson, G. N., Ärnlöv, J., & Vessby, B.
Affiliations
  • From the Department of Public Health and Caring Sciences/Geriatrics, Uppsala University (U.R., S.B., J.Ä., B.V.), Uppsala, Sweden, and the Department of Cardiology/Medicine, University Hospital MAS, Lund University (S.J., G.N.F.), Lund, Sweden.
  • Uppsala University (SE)
Venue
Circulation
Published
2002-10-08
Volume
106
Issue
15
Pages
1925-1929
ISSN
  • 0009-7322 (ISSN-L)
  • 1524-4539
OpenAlex
W2164592152
Cited by
292
References
32
Citations by year
2026: 1 · 2025: 1 · 2024: 3 · 2023: 1 · 2022: 5 · 2021: 4 · 2020: 5 · 2019: 7 · 2018: 2 · 2017: 4 · 2016: 10 · 2015: 7 · 2014: 9 · 2013: 20 · 2012: 9
FWCI
20.90
Type
journal article
Language
en
Open access
closed
Locations
  • Circulation (publishedVersion)
  • PubMed (publishedVersion)
  • Lund University Publications (Lund University) (submittedVersion)
Funders
Medical Research Council
Topics
  • Health Sciences › Nursing › Nutrition and Dietetics › Fatty Acid Research and Health
  • Health Sciences › Medicine › Biochemistry › Antioxidant Activity and Oxidative Stress
  • Health Sciences › Medicine › Epidemiology › Adipokines, Inflammation, and Metabolic Diseases
Keywords
conjugated linoleic acid, CLA isomers, oxidative stress, lipid peroxidation, C-reactive protein, inflammation, insulin resistance, metabolic syndrome, obesity, weight loss supplements, vitamin E, 8-isoprostane
MeSH terms
Adult, Aged, Blood Glucose, C-Reactive Protein, Double-Blind Method, Humans, Inflammation, Insulin Resistance, Isomerism, Kinetics, Linoleic Acids, Lipoproteins, VLDL, Male, Middle Aged, Triglycerides, Lipid Peroxidation, Biomarkers, Cytokines, Oxidative Stress, Anti-Obesity Agents, Metabolic Syndrome, F2-Isoprostanes

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