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 .
Soy proteins and isoflavones affect bone mineral density in older women: a randomized controlled trial.
BACKGROUND Soy foods contain several components ( isoflavones and amino acids ) that potentially affect bone . Few long-term , large clinical trials of soy as a means of improving bone mineral density ( BMD ) in late postmenopausal women have been conducted . OBJECTIVE Our goal was to evaluate the long-term effect of dietary soy protein and /or soy isoflavone consumption on skeletal health in late postmenopausal women . DESIGN We conducted a r and omized , double-blind , placebo-controlled clinical trial in 131 healthy ambulatory women aged > 60 y. Ninety-seven women completed the trial . After a 1-mo baseline period , subjects were r and omly assigned into 1 of 4 intervention groups : soy protein ( 18 g ) + isoflavone tablets ( 105 mg isoflavone aglycone equivalents ) , soy protein + placebo tablets , control protein + isoflavone tablets , and control protein + placebo tablets . RESULTS Consumption of protein powder and isoflavone pills did not differ between groups , and compliance with the study powder and pills was 80 - 90 % . No significant differences in BMD were observed between groups from baseline to 1 y after the intervention or in BMD change between equol and non-equol producers . However , there were significant negative correlations between total dietary protein ( per kg ) and markers of bone turnover ( P < 0.05 ) . CONCLUSIONS Because soy protein and isoflavones ( either alone or together ) did not affect BMD , they should not be considered as effective interventions for preserving skeletal health in older women . The negative correlation between dietary protein and bone turnover suggests that increasing protein intakes may suppress skeletal turnover . This trial was registered at Clinical Trials.gov as NCT00668447
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 .