Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland.
PLoS One. 2009 Sep 30;4(9):e7281. doi: 10.1371/journal.pone.0007281.
Emerging evidence suggests that dietary soy and phytoestrogens can have beneficial effects on lipid and glucose metabolism. We have previously shown that male mice fed from conception to adulthood with a high soy-containing diet had reduced body weight, adiposity and a decrease in glucose intolerance, an early marker of insulin resistance and diabetes.
The purpose of this study was to identify the precise periods of exposure during which phytoestrogens and dietary soy improve lipid and glucose metabolism. Since intrauterine position (IUP) has been shown to alter sensitivity to endocrine disruptors, we also investigated whether the combination of IUP and fetal exposure to dietary phytoestrogens could potentially affect adult metabolic parameters.
Male outbred mice (CD-1) were allowed ad libitum access to either a high soy-containing diet or a soy-free diet either during gestation, lactation or after weaning. Adiposity and bone mass density was assessed by dual x-ray absorptiometry. Glucose tolerance was assessed by a glucose tolerance test. Blood pressure was examined by the tail-cuff system.
Here we show that metabolic improvements are dependent on precise windows of exposure during life. The beneficial effects of dietary soy and phytoestrogens on adiposity were apparent only in animals fed post-natally, while the improvements in glucose tolerance are restricted to animals with fetal exposure to soy. Interestingly, we observed that IUP influenced adult glucose tolerance, but not adiposity. Similar IUP trends were observed for other estrogen-related metabolic parameters such as blood pressure and bone mass density.
Our results suggest that IUP and fetal exposure to estrogenic environmental disrupting compounds, such as dietary phytoestrogens, could alter metabolic and cardiovascular parameters in adult individuals independently of adipose gain.
新出现的证据表明，饮食中的大豆和植物雌激素对脂质和葡萄糖代谢可能有有益的影响。我们之前已经表明，从受孕到成年期一直用高大豆含量饮食喂养的雄性小鼠体重减轻、肥胖减少且葡萄糖耐量降低，葡萄糖耐量降低是胰岛素抵抗和糖尿病的早期标志物。
本研究的目的是确定植物雌激素和饮食大豆改善脂质和葡萄糖代谢的确切暴露时期。由于宫内位置（IUP）已被证明会改变对内分泌干扰物的敏感性，我们还研究了 IUP 和胎儿暴露于饮食植物雌激素的组合是否可能影响成年代谢参数。
雄性近交系小鼠（CD-1）可自由选择高大豆含量饮食或无大豆饮食，可在妊娠期、哺乳期或断奶后使用。通过双能 X 线吸收法评估肥胖和骨密度。通过葡萄糖耐量试验评估葡萄糖耐量。通过尾套系统检查血压。
我们在此表明，代谢改善取决于生命中精确的暴露窗口。饮食大豆和植物雌激素对肥胖的有益影响仅在出生后喂养的动物中显现，而葡萄糖耐量的改善仅限于胎儿暴露于大豆的动物。有趣的是，我们观察到 IUP 影响成年葡萄糖耐量，但不影响肥胖。类似的 IUP 趋势也观察到其他与雌激素相关的代谢参数，如血压和骨密度。
我们的结果表明，IUP 和胎儿暴露于雌激素环境破坏化合物（如饮食植物雌激素）可能独立于脂肪增加而改变成年个体的代谢和心血管参数。
