停經婦女攝取山藥對血脂、抗氧化能力與性激素的影響 摘要 本研究為釐清古今中外傳聞山藥有促進性激素活性與瞭解山藥對血脂、抗氧化的影響。招募本校附近健康、飲食規律、半年內無使用雌激素的停經婦女共23位。以山藥餐點取代受試者一天中約2/3的主食 (約390g/天),共29天,期間維持體重不變。食用前後收集血液與尿液共兩次,比較血糖、血脂(血漿及各種脂蛋白中的三酸甘油酯、膽固醇含量)、抗氧化(血清中總抗氧化狀態、LDL氧化遲滯期和 Thiobarbituric acid reactive substance (TBARS)產生量、尿液isoprostane排出量)與性激素﹝血清Estrone、Estradiol、Sex-hormone binding globulin (SHBG)、Dehydroepiandrosterone sulfate (DHEAS)、Testosterone、Androstenedione、Follicle stimulating hormone、Luteinizing hormone與尿液雌激素代謝物﹞的變化。結果顯示,攝食山藥後,身體組成與熱量攝取皆無顯著變化。血漿總膽固醇的濃度降低 (p=0.012),但血漿三酸甘油酯與各種脂蛋白中的膽固醇、三酸甘油酯及血糖無顯著改變;尿液中isoprostane 的濃度顯著減少(p=0.000), LDL在體外以銅氧化的遲滯期延長 (p=0.058),表示山藥提供抗氧化性,但血清總抗氧化狀態與LDL氧化TBARS產生量並無顯著改變;血清中Estrone (p=0.025)、SHBG (p=0.04) 與Estradiol (p=0.075) 的濃度上升,尿液雌激素代謝物總量與16α-OHE1的排出量降低 (p=0.002)。結論,山藥可下降血漿總膽固醇,促進抗氧化能力,增加血液雌激素、性激素結合蛋白質的濃度與降低尿液雌激素的代謝物16α-hydroxyestrone排出量,對停經婦女在乳癌與心血管疾病的預防上也許會有助益。
The effects of dietary Dioscorea on blood lipids, antioxidant status and sex hormones in postmenopausal women Abstract To investigate the effects of Dioscorea intake on the levels of blood lipids, antioxidant capacity and sex-hormones, 23 apparently healthy postmenopausal women with regular dietary habit and without hormone replacement therapy for at least 6 months were recruited. During intervention, rice in 2 of 3 meals was replaced by Dioscorea ( ~390 g/d) for 29 days and body weights were maintained constantly. Fasting blood and first morning urine samples were collected before and after Dioscorea intervention for the measurements of blood sugar, blood lipids, antioxidant capacity (the susceptibility of LDL to oxidation, serum total antioxidant status and urinary isoprostane level) and sex hormones (serum Estrone, Estradiol, Sex hormone binding globulin (SHBG), Dehydroepiandrosterone sulfate (DHEAS), Testosterone, Androstenedione, Follicle stimulating hormone, Luteinizing hormone and urinary estrogen metabolites). The results showed that plasma total cholesterol concentration(p=0.012), urinary isoprostane (p=0.000) and genotoxic estrogen metabolite (16α-OHE1) (p=0.002) excretion decreased significantly, serum Estrone (p=0.025) and SHBG (p=0.04) concentrations increased significantly. Estradiol concentrations increased but the increase did not reach a significant level (p=0.075). The lag time of conjugated diene formation of LDL oxidized by copper was longer than at the baseline (p=0.058). There were no significant difference in body composition, total calorie intake, blood sugar, plasma triglycerides, serum total antioxidant status, and other hormones measured when compared with those at the baseline. This study showed that Dioscorea intake improved estrogen status, increased protective SHBG, antioxidative ability and decreased plasma cholesterol in postmenopausal women and might suggest the beneficial effects of Dioscorea in decreasing the risks of breast cancer and cardiovascular diseases.