芝麻對停經婦女性激素與血脂的影響

Abstract

本研究目的為探討芝麻對停經婦女血液性激素、血脂與抗氧化之影響。招募師大附近健康、飲食規律、停經一年以上、半年內無使用雌激素補充治療之婦女24人，實驗採用cross-over設計，每日分別食用50克泰國黑芝麻（薌園）或安慰劑（米粉）各5週，中間間隔3週清除期。食用芝麻或安慰劑前後收集血液與尿液共四次，比較血脂（血漿及各脂蛋白中三酸甘油酯、膽固醇含量）、抗氧化〔LDL氧化遲滯期、thiobarbituric acid reactive substance（TBARS）產生量、血清α與γ-tocopherol含量〕、雌激素〔血清estrone、estradiol、sex-hormone binding gloubin（SHBG）、dehydroepiandorsterone sulfate（DHEAS）、follicle stimulation hormone（FSH）〕、血糖、血清脂肪酸組成、尿液bicyclo PGE2與鈣、鈉、鉀、氯排出的變化。結果顯示，攝取芝麻後各生化值改變量與攝取米粉後改變量比較，血清SHBG顯著上升（p=0.028）、DHEAS顯著下降（p=0.010）；血漿總膽固醇（p=0.072）、LDL-C（p=0.060）有下降的趨勢；體外以銅氧化LDL之TBARS產生量顯著降低（p=0.031），且血清γ-tocopherol∕total lipid呈明顯上升（p=0.000）；血清linoleic acid顯著增加（p=0.018），arachidonic acid∕linoleic acid則顯著下降（p=0.008）；尿鈣濃度顯著下降（p=0.037）。綜合上述，芝麻可增強體內抗氧化能力；此外，對SHBG增高與DHEA降低的作用，或許能減少乳癌、心血管疾病發生之危險；對尿鈣排出量的降低，也許可減少骨質流失。故攝取芝麻對停經婦女在乳癌、心血管疾病的預防與骨骼健康的維護或許有所裨益。

Objective: The effects of sesame on sex hormone, blood lipids and antioxidative status were investigated in postmenopausal women.

Methods: Twenty-four apparently healthy postmenopausal women without hormone replacement therapy participated in this single-blind and randomized crossover-controlled trials. Subjects were supplemented with 50 g either sesame powder or rice powder placebo daily for 5 weeks each which were intervened by a wash-out period of 3 weeks. Fasting blood and first morning urine samples were collected at baseline and at the end of each feeding phase for the measurements of blood lipids, antioxidant capacity (the susceptibility of LDL to oxidation and serum α and γ-tocopherol), serum sex hormones [serum estrone, estradiol, sex-hormone binding globulin (SHBG), dehydroepiandor- sterone sulfate (DHEAS), follicle stimulation hormone (FSH) ], serum fatty acid composition, urine bicylo PGE2, urine electrolytes (calcium, sodium, potassium and chloride) and blood sugar.

Results: Comparing the changes from baseline between sesame and rice supplementation, sesame supplementation increased serum SHBG (p=0.028), decreased serum DHEAS (p=0.010), decreased plasma cholesterol (p=0.072), LDL-C (p=0.060) and thiobarbituric acid reactive substances (TBARS) production of LDL oxidized by copper in vitro (p=0.031) and increased γ-tocopherol/total lipid ratio (p=0.000). Serum linoleic acid level (p=0.018) increased and arachidonic acid/linoleic acid ratio decreased (p=0.008) by sesame supplementation. Among the urinary electrolytes measured, only a decrease of calcium excretion was found after sesame consuming (p=0.037).

Conclusion: These data indicate that sesame is effective in enhancing antioxidative ability. The increased SHBG and decreased DHEA may have beneficial effect in protecting postmenopasal women from breast cancer and cardiovascular disease. Moreover, the decrease of urinary calcium may indicate the reduction of bone lose.