Conjugated Linoleic Acid and Metabolic Syndrome: A Systematic Review

Although، most of the experimental studies demonstrated that conjugated linoleic acid has effects on metabolic syndrome، but the number of human studies in this area are limited and the result of these studies are controversial. This systematic review was conducted to summarize the literature from clinical trials and experimental studies regarding the effect of each conjugated linoleic acid (CLA) isomers on component of metabolic syndrome. Relevant studies were identified by searching scientific databases of PubMed and ISI during 2000 until 2012. Clinical trials and experimental studies regarding the effect of 9 cis، 11 trans and 10 trans، 12 cis and mixed CLA on component of metabolic syndrome including insulin resistance، obesity، dyslipidemia and hypertension were included in this systematic review. From 320 articles that were found in this area، 24 articles that had the inclusion criteria were selected. Most of the experimental studies have shown that conjugated linoleic acid can improve insulin resistance and lipid profile in animals، whereas clinical trials could not demonstrate this effects of CLA on humans. Each isomers of CLA have different effects، that is، 9 cis، 11 trans have role in reducing insulin resistance and improving lipid profile and 10 trans، 12 cis isomers have role in improving hypertension.