A new study out of Hong Kong suggests that soy supplements do not benefit type 2 diabetics.
According to a Reuters report, previous lab research has suggested that soy proteins and soy isoflavones — “phytoestrogen” compounds that are structurally similar to human estrogen — may help control blood sugar levels. But so far, the few small clinical trials that have been done have reached different conclusions as to whether soy foods or soy-protein supplements are actually beneficial to people with diabetes.
In the new study, researchers recruited 180 postmenopausal women who either had pre-diabetes or were in the early stages of type 2 diabetes and had not yet started any treatment. The women were divided into three groups: one that took a powdered supplement containing milk protein; one that took a supplement of milk protein plus soy isoflavones; and a third that took a soy-protein supplement with additional isoflavones. After six months, there was no clear benefit of either the soy or the milk-plus-isoflavone supplement in the women’s blood sugar control or levels of insulin.
One exception, the researchers noted, was that there was a “marginally favorable effect” of the soy supplement on women’s blood sugar levels two hours after eating.
The researchers concluded that the findings do not support the theory that soy or isoflavone supplements benefit overall blood sugar control in women like those in the study. The findings, however, should not be seen as the final word on soy and diabetes.