Iwata Toshio, Kamegai Takeshi, Yamauchi-Sato Yoshie, Ogawa Akiko, Kasai Michio, Aoyama Toshiaki, Kondo Kazuo
Research Laboratory, The Nisshin OilliO Group, Ltd., Tokyo, Japan.
J Oleo Sci. 2007;56(10):517-25. doi: 10.5650/jos.56.517.
A study was conducted to investigate the short-term safety of dietary conjugated linoleic acid (CLA) in overweight Japanese male volunteers. The study design was a randomized, double-blind placebo-controlled trial including 60 healthy overweight volunteers (body mass index (BMI), 25 approximately 35 kg/m(2)). The subjects were randomly assigned to three groups: 5.4 g CLA-triacylglycerol (3.4 g as CLA), 10.8 g CLA-triacylglycerol (6.8 g as CLA) and placebo (10.8 g safflower oil) daily for 12 weeks. The CLA-triaclyglycerol contained 9c,11t- and 10t,12c-isomers at an equal proportion. The safety was evaluated by analyses of blood parameters and by clinical examinations at the baseline, and at 6 and 12 weeks, including vital signs and adverse effects. All subjects completed the study. The occurrence of adverse events tended to be higher in the CLA groups than in the placebo group, but all of the adverse events were mild to moderate, within normal ranges, and temporary. Serum aspartate aminotransferase (AST) activity did not differ significantly between the groups at 12 weeks, but in the high CLA group it was slightly increased from the baseline. Serum alanine aminotransferase (ALT) activity was higher in the high CLA group than in the placebo group after 12 weeks and was higher than at the baseline in both CLA groups. However, statistical analysis of the population of apparently healthy volunteers who had normal blood parameters at the baseline revealed that AST and ALT levels did not differ significantly among the 3 groups at 12 weeks. Moreover, no clinically significant changes in vital signs were observed in any of the groups. These results indicate that CLA at a dose of 3.4 g/day is a safe dietary level in healthy Japanese populations in terms of the parameters examined.
一项研究旨在调查超重日本男性志愿者食用膳食共轭亚油酸（CLA）的短期安全性。该研究设计为随机、双盲、安慰剂对照试验，纳入60名健康超重志愿者（体重指数（BMI）为25至35kg/m²）。受试者被随机分为三组：每日分别摄入5.4g CLA-三酰甘油（相当于3.4g CLA）、10.8g CLA-三酰甘油（相当于6.8g CLA）和安慰剂（10.8g红花油），持续12周。CLA-三酰甘油中9c,11t-和10t,12c-异构体比例相等。通过分析血液参数以及在基线、6周和12周时进行临床检查来评估安全性，临床检查包括生命体征和不良反应。所有受试者均完成了研究。CLA组不良事件的发生率往往高于安慰剂组，但所有不良事件均为轻度至中度，在正常范围内且为暂时性。12周时，各组血清天冬氨酸氨基转移酶（AST）活性无显著差异，但高CLA组较基线略有升高。12周后，高CLA组血清丙氨酸氨基转移酶（ALT）活性高于安慰剂组，且两个CLA组均高于基线。然而，对基线血液参数正常的明显健康志愿者群体进行统计分析发现，12周时三组间AST和ALT水平无显著差异。此外，任何一组均未观察到生命体征有临床意义的变化。这些结果表明，就所检测的参数而言，每日3.4g的CLA剂量在健康日本人群中是安全的膳食水平。
