['Conjugated linoleic acid (CLA), a C18 fatty acid with conjugated double bonds, has been shown to serve as a powerful anti-obesity agent by several research groups, although the precise mechanism remains elusive. Previous studies showed that CLA induced apoptosis in 3T3-L1 cells and in mice. The aim of this research was to clarify the role of CLA in adipocyte apoptosis in pigs, a relevant model for obesity research.', 'Our results clearly show that back fat deposition of CLA-fed pigs was significantly lower than that of pigs in the control group. Moreover, some typical apoptotic cells were observed among the adipocytes of CLA-fed pigs. Furthermore, the CLA-fed pigs had reduced expression of the anti-apoptosis factor Bcl-2 and increased expression of the pro-apoptosis factors Bax and P53. Subsequently, increased cytochrome C was released from the mitochondria to the endochylema, and the caspase cascade was activated, resulting in cellular apoptosis. These results are consistent with the effects of Bcl-2 and Bax in regulating CLA-induced adipocyte apoptosis via the mitochondrial signaling pathway. However, the increased expression of tumor necrosis factor (TNF)-α and its receptor TNFR indicate that the effect of CLA might partly be through the death receptor signaling pathway in adipose cells.'] Does supplementation with conjugated linoeic acid decrease pig back fat deposition by inducing adipocyte apoptosis?