Banu Jameela, Bhattacharya Arunabh, Rahman Mizanur, Fernandes Gabriel
Department of Medicine, Division of Clinical Immunology and Rheumatology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
J Bone Miner Metab. 2008;26(5):436-45. doi: 10.1007/s00774-008-0863-3. Epub 2008 Aug 30.
Conjugated linoleic acids (CLA) are a group of polyunsaturated fatty acids that has recently been shown to have several beneficial effects on different diseases, including prevention of bone loss. The important feature of CLA is to reduce fat mass, thereby reducing body weight significantly. Although loss of body weight is known to increase bone loss, there is increasing evidence that CLA maybe beneficial to bone. Another factor that can reduce body weight is exercise (EX). It is well established that moderate EX stimulates bone formation. In this study, we analyzed the changes in bone using pQCT densitometry in middle-aged C57Bl/6 mice fed CLA (0.5%) and/or exercised. Twelve-month-old mice were divided into the following groups: group 1, corn oil, sedentary (CO SED); group 2, corn oil, exercise (CO EX); group 3, CLA, sedentary (CLA SED); and group 4, CLA, exercise (CLA EX). Mice were maintained in the respective experimental regimens for 10 weeks, after which mice were scanned using DEXA and killed. The lumbar vertebrae, femur, and tibia were analyzed using pQCT densitometry. CLA, when given alone or in combination with EX, significantly reduced body weight and increased lean mass. CLA treatment also significantly increased bone mass. Further, additional increase in bone mass was observed in mice treated with a combination of CLA and EX in almost all the bone sites analyzed. We conclude that CLA, when consumed as a dietary supplement along with moderate treadmill EX, significantly increases bone mass in middle-aged female mice.
共轭亚油酸（CLA）是一类多不饱和脂肪酸，最近的研究表明其对包括预防骨质流失在内的多种疾病具有多种有益作用。CLA的重要特性是减少脂肪量，从而显著降低体重。虽然已知体重减轻会增加骨质流失，但越来越多的证据表明CLA可能对骨骼有益。另一个能减轻体重的因素是运动（EX）。众所周知，适度运动能刺激骨骼形成。在本研究中，我们使用外周定量计算机断层扫描骨密度仪分析了喂食CLA（0.5%）和/或进行运动的中年C57Bl/6小鼠的骨骼变化。将12月龄的小鼠分为以下几组：第1组，玉米油，久坐不动（CO SED）；第2组，玉米油，运动（CO EX）；第3组，CLA，久坐不动（CLA SED）；第4组，CLA，运动（CLA EX）。小鼠在各自的实验方案中维持10周，之后使用双能X线吸收仪对小鼠进行扫描并处死。使用外周定量计算机断层扫描骨密度仪分析腰椎、股骨和胫骨。单独给予CLA或与EX联合使用时，均能显著降低体重并增加瘦体重。CLA治疗还能显著增加骨量。此外，在几乎所有分析的骨部位，CLA与EX联合治疗的小鼠骨量进一步增加。我们得出结论，当作为膳食补充剂与适度的跑步机运动一起食用时，CLA能显著增加中年雌性小鼠的骨量。
