Effects of Varying Unsaturated Fatty Acid Composition on the Lipid Metabolism and Body Fat Accumulation

• Main Authors: Fang-Hsuean Liao, 廖芳瑄
• Other Authors: 謝明哲
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/32524914888248802751

博士 === 臺北醫學大學 === 保健營養學研究所 === 98 === The aim of this study was to assess the relationship between high monounsaturated fatty acid (MUFA) with different levels of polyunsaturated-to-saturated fatty acid (P/S) ratios and body fat accumulation. We designed a 2 x 2 factorial study, with 2 levels of MUFAs (60% and 30%) and 2 levels of the polyunsaturated-to-saturated fatty acid (P/S) ratio (5 and 3) to prepare four kinds of experimental oils consisting of 60% MUFAs with a high or low P/S ratio, or 30% MUFAs with a high or low P/S ratio. Forty male golden Syrian hamsters were randomly divided into five groups and fed the diets contained 15% (w/w) fat for 12 weeks. Hamsters fed soybean oil were as control group. No difference was observed in the mean daily food intake. Hamsters fed the high MUFA% with high P/S ratio diet had lower not only plasma insulin and free fatty acid concentrations but also hepatic acetyl-CoA carboxylase activities, and elevated hepatic acyl-CoA oxidase and carnitine palmitoyltransferase-I activities among the groups. The high MUFA% with high P/S ratio oil diet appeared to be beneficial in preventing white adipose tissue accumulation. In diet-induced obese (DIO) models, DIO hamsters fed the high MUFA% with high P/S ratio oil diet had significant reductions in white adipose tissue deposition and plasma leptin levels, suppression in adipose peroxisome proliferator-activated receptors (PPAR) γ and lipoprotein lipase (LPL) mRNA expressions and increases in hepatic lipolytic enzyme activities compared with those in the obese-control group. The high MUFA% with high P/S ratio oil group upregulated phosphorylation of hormone-sensitive lipase (HSL) relative to total HSL protein levels compared with the olive oil group. However, the olive oil consisting of the high MUFA% with very low P/S ratio group significantly elevated hepatic FAS activities (de novo lipogenesis) compared with the high MUFA% with high P/S ratio oil group. Moreover, we found effects of body fat accumulation of P/S ratio were more important than those of MUFA/PUFA ratio in 3T3-L1 adipocyte, suggesting that SFA, MUFA and PUFA are needed to consist of the optimal dietary fat composition. In conclusion, 60% MUFA with P/S ratio=5 oil appeared to be beneficial in preventing white adipose tissue accumulation.