A preliminary study presented at the Society for Endocrinology annual conference in Edinburgh, UK reported that isoflavones, a type of phytoestrogen found in soy and other legumes, may protect menopausal women against osteoporosis.
The study split 200 menopausal women into two groups: one received a supplement containing soy proteins and isoflavones and the other received a supplement containing just the soy proteins.
The women took the supplements every day for 6 months, then the researchers examined blood for two markers of bone health, Î²CTX and P1NP. Although osteoporosis diagnosis is not based on these markers, both Î²CTX, a prominent marker of bone loss, and P1NP, a marker of bone formation, correlate well with the disease's presence.
The researchers reported that women in the treatment group had significantly lower levels of the Î²CTX when compared to women taking the control supplement.
There are qualifiers: The study was small, the results are preliminary, and it is unclear how effective markers like Î²CTX and P1NP are for diagnosing osteoporosis.
But it does highlight the importance of real, controlled, double-blind trials to determine the effectiveness of dietary supplements. If the science checks out on isoflavones it would be a huge benefit for the millions of women who experience osteoporosis as they go through menopause. Until then taking isoflavones, or other soy-based supplements, may lead to a false sense of health security.