Atkinson Charlotte, Compston Juliet E, Day Nicholas E, Dowsett Mitch, Bingham Sheila A
MRC Biostatistics Unit, Institute of Public Health, Robinson Way, Cambridge, United Kingdom.
Am J Clin Nutr. 2004 Feb;79(2):326-33. doi: 10.1093/ajcn/79.2.326.
Isoflavone phytoestrogen therapy has been proposed as a natural alternative to hormone replacement therapy (HRT). HRT has a beneficial effect on bone, but few trials in humans have investigated the effects of isoflavones on bone.
The objective of the study was to determine the effect on bone density of a red clover-derived isoflavone supplement that provided a daily dose of 26 mg biochanin A, 16 mg formononetin, 1 mg genistein, and 0.5 mg daidzein for 1 y. Effects on biochemical markers of bone turnover and body composition were also studied.
Women aged 49-65 y (n = 205) were enrolled in a double-blind, randomized, placebo-controlled trial; 177 completed the trial. Bone density, body composition, bone turnover markers, and diet were measured at baseline and after 12 mo.
Loss of lumbar spine bone mineral content and bone mineral density was significantly (P = 0.04 and P = 0.03, respectively) lower in the women taking the isoflavone supplement than in those taking the placebo. There were no significant treatment effects on hip bone mineral content or bone mineral density, markers of bone resorption, or body composition, but bone formation markers were significantly increased (P = 0.04 and P = 0.01 for bone-specific alkaline phosphatase and N-propeptide of collagen type I, respectively) in the intervention group compared with placebo in postmenopausal women. Interactions between treatment group and menopausal status with respect to changes in other outcomes were not significant.
These data suggest that, through attenuation of bone loss, isoflavones have a potentially protective effect on the lumbar spine in women.
异黄酮植物雌激素疗法已被提议作为激素替代疗法（HRT）的天然替代品。HRT对骨骼有有益作用，但针对异黄酮对骨骼影响的人体试验较少。
本研究的目的是确定一种来源于红三叶草的异黄酮补充剂对骨密度的影响，该补充剂每日提供26毫克鹰嘴豆芽素A、16毫克芒柄花黄素、1毫克染料木黄酮和0.5毫克大豆苷元，持续服用1年。还研究了其对骨转换生化标志物和身体成分的影响。
49 - 65岁的女性（n = 205）参与了一项双盲、随机、安慰剂对照试验；177人完成了试验。在基线和12个月后测量骨密度、身体成分、骨转换标志物和饮食情况。
服用异黄酮补充剂的女性腰椎骨矿物质含量和骨密度的损失显著低于服用安慰剂的女性（分别为P = 0.04和P = 0.03）。在髋部骨矿物质含量、骨密度、骨吸收标志物或身体成分方面没有显著的治疗效果，但与安慰剂相比，绝经后女性干预组的骨形成标志物显著增加（骨特异性碱性磷酸酶和I型胶原N端前肽分别为P = 0.04和P = 0.01）。治疗组与绝经状态在其他结局变化方面的相互作用不显著。
这些数据表明，通过减少骨质流失，异黄酮对女性腰椎可能具有潜在的保护作用。
