Conclusions : Isoflavone treatments exert a moderately beneficial effect against  estrogen-deficient bone loss in women .
The effect appears dependent on whether isoflavone treatments are in aglycone form ; we conclude that beneficial effects against bone loss may be enhanced for isoflavone aglycones
Background : Age-related estrogen deficiency leads to accelerated bone resorption .
There is evidence that , through selective estrogen receptor modulation , isoflavones may exert beneficial effects against  estrogen-deficient bone loss .
Isoflavone aglycones show higher bioavailability than their glycosidic counterparts and thus may have greater potency .
Objective : To summarize evidence , we executed a systematic review and meta- analysis examining isoflavone therapies and bone mineral density ( BMD ) loss in peri- and postmenopausal women .
Isoflavone-rich soy protein isolate attenuates bone loss in the lumbar spine of perimenopausal women.
BACKGROUND No published studies have directly examined the effect of soy protein with isoflavones on bone or bone turnover  in perimenopausal women . OBJECTIVE Our objective was to determine the effects of 24 wk of consumption of soy protein isolate with isoflavones ( 80.4 mg/d ) in attenuating bone loss during the menopausal transition . DESIGN Perimenopausal subjects were r and omly assigned , double blind , to treatment : isoflavone-rich soy ( SPI+ ; n = 24 ) , isoflavone-poor soy ( SPI- ; n = 24 ) , or whey ( control ; n = 21 ) protein . At baseline and posttreatment , lumbar spine bone mineral density ( BMD ) and bone mineral content ( BMC ) were measured by using dual-energy X-ray absorptiometry . At baseline , midtreatment , and posttreatment , urinary N:-telopeptides and serum bone-specific alkaline phosphatase ( BAP ) were measured . RESULTS The percentage change in lumbar spine BMD and BMC , respectively , did not differ from zero in the SPI+ or SPI- groups , but loss occurred in the control group ( -1.28 % , P : = 0.0041 ; -1.73 % , P : = 0.0037 ) . By regression analysis , SPI+ treatment had a positive effect on change in BMD ( 5.6 % ; P : = 0.023 ) and BMC ( 10.1 % ; P : = 0.0032 ) . Baseline BMD and BMC ( P : < or = 0.0001 ) negatively affected the percentage change in their respective models ; baseline body weight ( P : = 0.0036 ) and bone-free lean weight ( P : = 0.016 ) contributed positively to percentage change in BMD and BMC , respectively . Serum BAP posttreatment was negatively related to percentage change in BMD ( P : = 0.0016 ) and BMC ( P : = 0.019 ) . Contrast coding using analyses of covariance with BMD or BMC as the outcome showed that isoflavones , not soy protein , exerted the effect . CONCLUSION Soy isoflavones attenuated bone loss from the lumbar spine in perimenopausal women
Conclusions : Isoflavone treatments exert a moderately beneficial effect against  estrogen-deficient bone loss in women .
The effect appears dependent on whether isoflavone treatments are in aglycone form ; we conclude that beneficial effects against bone loss may be enhanced for isoflavone aglycones
Background : Age-related estrogen deficiency leads to accelerated bone resorption .
There is evidence that , through selective estrogen receptor modulation , isoflavones may exert beneficial effects against  estrogen-deficient bone loss .
Isoflavone aglycones show higher bioavailability than their glycosidic counterparts and thus may have greater potency .
Objective : To summarize evidence , we executed a systematic review and meta- analysis examining isoflavone therapies and bone mineral density ( BMD ) loss in peri- and postmenopausal women .