Article

Conjugated linoleic acid supplementation, insulin sensitivity, and lipoprotein metabolism in patients with type 2 diabetes mellitus.

Nutrigenomics Research Group, Department of Clinical Medicine, Trinity Centre for Health Sciences, Dublin, Ireland.
American Journal of Clinical Nutrition (Impact Factor: 6.92). 11/2004; 80(4):887-95.
Source: PubMed

ABSTRACT Some animal studies have suggested that conjugated linoleic acid (CLA) supplementation may have therapeutic potential with respect to insulin sensitivity and lipid metabolism, which are important cardiovascular disease (CVD) risk factors associated with type 2 diabetes mellitus.
We investigated the effect of CLA supplementation on markers of glucose and insulin metabolism, lipoprotein metabolism, and inflammatory markers of CVD in subjects with type 2 diabetes.
The study was a randomized, double-blind, placebo-controlled trial. Thirty-two subjects with stable, diet-controlled type 2 diabetes received CLA (3.0 g/d; 50:50 blend of cis-9,trans-11 CLA and trans-10,cis-12 CLA) or control for 8 wk. A 3-h 75-g oral-glucose-tolerance test was performed, and fasting plasma lipid concentrations and inflammatory markers were measured before and after the intervention.
CLA supplementation significantly increased fasting glucose concentrations (6.3%; P < 0.05) and reduced insulin sensitivity as measured by homeostasis model assessment, oral glucose insulin sensitivity, and the insulin sensitivity index (composite) (P = 0.05). Total HDL-cholesterol concentrations increased by 8% (P < 0.05), which was due to a significant increase in HDL(2)-cholesterol concentrations (P < 0.05). The ratio of LDL to HDL cholesterol was significantly reduced (P < 0.01). CLA supplementation reduced fibrinogen concentrations (P < 0.01) but had no effect on the inflammatory markers of CVD (C-reactive protein and interleukin 6).
CLA supplementation had an adverse effect on insulin and glucose metabolism. Whereas CLA had positive effects on HDL metabolism and fibrinogen, a therapeutic nutrient should not be associated with potentially adverse effects on other clinical markers of type 2 diabetes.

Full-text

Available from: Helen Roche, May 29, 2015
0 Followers
 · 
80 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Little information about the effects of conjugated linoleic acids (CLAs) on inflammation and immune function in humans is available. This study investigated the effects of CLAs, with and without Vitamin E on immunity and inflammatory parameters in adults with active rheumatoid arthritis (RA). In a double-blind clinical trial, 78 patients were randomly divided into four groups, each group receiving one of the following daily supplement for 3 months; group C: 2.5 g CLAs, group E: 400 mg Vitamin E, group CE: CLAs plus Vitamin E, group P: Placebo. Cytokines, matrix metalloproteinase 3 (MMP-3) and citrullinated antibody (CCP-A) were measured by ELISA method and Vitamin E by high-performance liquid chromatography. Consider statistical methods there were no significant differences between groups in cytokines interleukin-2 (IL-2), IL-4, tumor necrosis factor-α (TNF-α), IL-1β, IL-2/IL-4, CCP-A white blood cells and neutrophils, lymphocyte, monocytes, and eosinophils numbers. TNF-α decreased in all groups, but its reduction was significant in group CE. IL-1β increased in groups P (P = 0.004) and E (P = 0.041) but the difference between group P and CE was significant. IL-4 decreased in groups C, CE and E (P = 0.03, P = 0.03, P = 0.07 respectively). IL2 did not change significantly within groups. CCP-A increased in groups P (P = 0.035) and E (P = 0.05), while it decreased in groups CE (P = 0.034). CCP-A and MMP-3 decrease were significant between groups P and CE. MMP-3 reduction was significant in group CE. Co-supplementation CLAs and Vitamin E may be effective in the level of inflammatory markers in RA patients.
    International journal of preventive medicine 12/2014; 5(12):1567-77.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dietary fatty acids (FA) are increasingly recognized as major biologic regulators and have properties that relate to health outcomes and disease. Conjugated linoleic acid (CLA) is a generic term denoting a group of isomers of linoleic acid (C18:2, n-6) with a conjugated double bond. CLA has attracted increased research interest because of its health-promoting benefits and biological functions. In a variety of studies, CLA has been shown to impact immune function and has protective effects against cancer, obesity, diabetes, and atherosclerosis in animal studies and in different human cell lines. Studies investigating the mechanisms involved in the biological functions of CLA are emerging with results from both in vivo and in vitro studies. Most of the biological effects have been attributed to the c9,t11-CLA and t10,c12-CLA isomers. The purpose of this review is to discuss the effects of CLA on health and disease and the possible mechanisms for CLA activities.
    Journal of Functional Foods 05/2015; 15:314-325. DOI:10.1016/j.jff.2015.03.050 · 4.48 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This comprehensive review critically evaluates whether supposed health benefits propounded upon human consumption of conjugated linoleic acids (CLAs) are clinically proven or not. With a general introduction on the chemistry of CLA, major clinical evidences pertaining to intervention strategies, body composition, cardio-vascular health, immunity, asthma, cancer and diabetes are evaluated. Supposed adverse effects such as oxidative stress, insulin resistance, irritation of intestinal tract and milk fat depression are also examined. It seems that no consistent result was observed even in similar studies conducted at different laboratories, this may be due to variations in age, gender, racial and geographical disparities, coupled with type and dose of CLA supplemented. Thus, supposed promising results reported in mechanistic and pre-clinical studies cannot be extrapolated with humans, mainly due to the lack of inconsistency in analyses, prolonged intervention studies, follow-up studies and international co-ordination of concerted studies. Briefly, clinical evidences accumulated thus far show that CLA is not eliciting significantly promising and consistent health effects so as to uphold it as neither a functional nor a medical food.
    Nutrition and metabolism 02/2015; 12. DOI:10.1186/1743-7075-12-4