Dem bones! Isoflavones, S-equol and aging

Posted by Liz on Feb 7, 2011 in bone health | 1 comment

I love it when readers of this blog point me to research that I might have missed or just not stumbled across. That happened a few weeks ago after I wrote a post on soy and safety. By following the links, reader Carol Land directed me to a newly published study on S-equol and bone health.

S-equol is a metabolite of a major soy isoflavone called daidzein. It has a particular affinity for estrogen receptors and possesses some estrogen-type activity of its own. S-equol  is produced in the gastrointestinal tract however the ability to actually manufacture it depends on the presence of certain microflora. Consequently, only 30% to 60% of individuals are actually able to produce S-equol on their own (although this figure is believed to be higher among Asians and vegetarians).

The surge in interest in S-equol is related to its potential for augmenting the benefits of isoflavones; in fact, it is possible that women who are naturally producers of S-equol actually experience greater effects from soy products, and this is especially true when it comes to bone health.

I cannot stress enough the importance of bone health as we age. Declining levels of estrogen are a primary cause of bone loss and resulting osteoporosis in women; indeed, one in five American women over the age of 50 have osteoporosis and about half will experience a fracture in the hip, wrist or spine as a result. What’s more, because osteoporosis is silent in its early stages, causing no symptoms, it’s critical that bone loss is halted or at least slowed either before or during the most critical phases strike. There is no time like the present to take preventive measures, even if you are in your 30s and 40s.

Where does S-equol fit in?

For the first time, researchers have shown the daily S-equol supplements taken by women who are not naturally producers of S-equol, may improve bone metabolism and attenuate bone loss!

In this 1 year study of 356 healthy, postmenopausal Japanese women between the ages of 41 and 62, daily intake of 10 mg S-equol via supplement markedly reduced markers of bone resorption in blood and urine compared to women taking placebo pills or 2 mg or 6 mg of S-equol daily. In fact, in women taking the 10 mg dose for a year, declines in a  urinary marker of bone resorption (i.e. DPD) were roughly 21% greater compared to placebo. Measures of whole body bone mineral density also showed that S-equol supplementation protected against bone loss, although not to the extent as bone resorption. These results remained even after changes in height, weight, body mass index, lean and fat mass were accounted for. No participant experienced serious side effects from taking S-equol and hormone levels were not adversely affected.

Does this mean that you should rush out and purchase S-equol supplements?

One of the primary limitations of this study is that the process of bone recycling can take as long as 18 months and the time required to complete a cycle may actually increase with age. Thus, the duration of time that the women were studied might be too short to draw any definitive conclusions. Hence,  you may want to wait before you start taking S-equol. However, the evidence that’s building continues to put the weight on the benefits versus risks side. Only time will tell. Meanwhile – here’s to your bone health. Keep on doing all you can do to keep dem bones.