Akhgarjand Camellia, Tavakoli Aryan, Samavat Simin, Bagheri Amir, Anoushirvani Aliarash, Mirzababaei Atieh, Amini Mohammad Reza, Ghorbi Mahmoud Dehghani, Valisoltani Neda, Mansour Asieh, Sajjadi-Jazi Sayed Mahmoud, Ansar Hastimansooreh, Rezvani Hamid
Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
Front Nutr. 2024 Mar 19;11:1336889. doi: 10.3389/fnut.2024.1336889. eCollection 2024.
Conjugated linoleic acid (CLA) is a geometrical isomer of linoleic acid, which has anti-inflammatory, anti-diabetic, anti-cancer, and anti-obesity properties. However, the studies reported inconstant results about the CLA-related effects on lipid profiles. As a result, meta-analysis and systematic review were performed to survey the CLA supplementation-related effect on lipid profile including high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol (TC), and triglycerides (TG). To identify the relevant research, a systematic comprehensive search was initiated on the medical databases such as Scopus and PubMed/Medline until December 2022. The overall effect size was estimated by weighted mean difference (WMD) and 95% confidence interval (CI) in a random effect meta-analysis. In the final quantitative analysis, the meta-analysis considered 35 randomized controlled trials (RCTs) with 1,476 participants (707 controls and 769 cases). The pooled results demonstrated that CLA supplementation, compared with olive oil, significantly increased serum TG levels (WMD: 0.05 mmol/L; 95% CI: 0.01 to 0.1; = 0.04; I = 0.0%, = 0.91). With regard to TC level, CLA supplementation compared with placebo significantly reduced TC concentrations (WMD: -0.08 mmol/L; 95% CI: -0.14 to -0.02; < 0.001; I = 82.4%). Moreover, the non-linear dose-response analysis indicated a decreasing trend of TC serum level from the 15th week of CLA supplementation compared with olive oil (P = 0.01). The present meta-analysis and systematic review of 35 RCTs showed that the CLA intervention was able to raise the level of TG in comparison to olive oil; however, it can decrease TC level compared with placebo and olive oil.
共轭亚油酸（CLA）是亚油酸的几何异构体，具有抗炎、抗糖尿病、抗癌和抗肥胖特性。然而，关于CLA对血脂影响的研究报告结果并不一致。因此，进行了荟萃分析和系统评价，以调查补充CLA对血脂的影响，包括高密度脂蛋白（HDL）、低密度脂蛋白（LDL）、总胆固醇（TC）和甘油三酯（TG）。为了确定相关研究，截至2022年12月，在Scopus和PubMed/Medline等医学数据库上开展了系统全面的检索。在随机效应荟萃分析中，通过加权平均差（WMD）和95%置信区间（CI）估计总体效应大小。在最终的定量分析中，荟萃分析纳入了35项随机对照试验（RCT），共1476名参与者（707名对照组和769名病例组）。汇总结果表明，与橄榄油相比，补充CLA显著提高了血清TG水平（WMD：0.05 mmol/L；95% CI：0.01至0.1；P = 0.04；I² = 0.0%，P = 0.91）。关于TC水平，与安慰剂相比，补充CLA显著降低了TC浓度（WMD：-0.08 mmol/L；95% CI：-0.14至-0.02；P < 0.001；I² = 82.4%）。此外，非线性剂量反应分析表明，与橄榄油相比，补充CLA第15周后血清TC水平呈下降趋势（P = 0.01）。本对35项RCT的荟萃分析和系统评价表明，与橄榄油相比，CLA干预能够提高TG水平；然而，与安慰剂和橄榄油相比，它可以降低TC水平。
