Natural estrogens have great appeal to women as an alternate to conventional hormones at and beyond the menopause. Concerns about the negative effects of standard drugs persuade some women to try phytoestrogens as a “softer option”.
It is difficult for clinicians to advise on such preparations as evidence of benefit - and more importantly harm - is lacking, and it has taken massive trials to uncover the small absolute detrimental effects of estrogens. Until equally stringent trials show the safety of phytoestrogens we will have to rely on smaller studies to show the way.
Marini et al (Ann Int Med 2007;146:839-47) have demonstrated in a RCT of 400 women that genistein, which is found in soy products, increases bone mineral density in osteopenic postmenopausal women. 54 mg of genistein daily for 2 years had positive effects on bone density and turnover compared with placebo, opening the way for long-term trials on fracture effects as well as uterine and breast safety.
