植物性雌激素與停經後婦女保健

Abstract

本文回顧植物性雌激素對停經後婦女更年期症狀、性激素、血脂與骨質影響的臨床研究，研究最多的是黃豆異黃酮，雖然研究結果並不一致，豆製品的有效成分是黃豆蛋白或異黃酮也仍有爭議，但有一些報告顯示可改善停經症狀、血脂與骨質，對雌激素代謝途徑與血液性激素結合蛋白濃度的影響有助乳癌的預防，且不具有雌激素刺激子宮內膜生長的壞處。少部分研究是探討亞麻籽、山藥與十字花料的indole-3-carbinol，三者都如同黃豆異黃酮，使雌激素代謝走向低活性產物，而亞麻籽可降低血脂，但對骨質沒有發現助益。植物性雌激素的不一致研究結果，可能與其生物利用率因人而異有關，其效果雖遠不如傳統動物性雌激素，但不致增高乳癌與心血管疾病危險性，若合併食用多種含植物性雌激素的食物，是否會有加成效果值得進一步研究。

This review includes recent clinical evidence that phytoestrogens relieve menopausal symptoms and prevent cardiovascular diseases and osteoporosis in postmenopausal women. Soy isoflavones have been the most extensively investigated. Although the effects are not consistent and whether the effective component is soy protein or an isoflavone is still controversial, some studies have indicated their effects on reducing hot flash symptoms and blood lipids, improving bone mass, changing sex hormone metabolites, and increasing sex hormone-binding globulin levels, which might confer an anti-breast cancer effect. Moreover, they do not cause stimulation of the endometrium. A few studies have focused on flaxseed, yams and on indole-3-carbinol of cruciferous vegetables. All of them switch the metabolism of estrone to a less- carcinogenic pathway. Flaxseed lowers blood lipids but has no effect on bone mass. The inconsistent results of phytoestrogen research might have resulted from variations in the bioavailabilities of phytoestrogens among individuals. Although the relative potencies of phytoestrogens as compared to estradiol are small, they do not increase the risks of breast cancer and cardiovascular diseases as does the traditional estrogen therapy. Since the phytoestrogenic components in most foods are not well known, we suggest consuming a variety of phytoestrogen-containing natural foods to hopefully obtain additive effects.