As I stated, I avoid soy... but one has to wonder in these "studies" where the soy comes from; is it Genetically-Modified-Organisms or non-GMO, organic or non-organic? How is it processed before consumption; isolates, oils etc in their parts or is it consumed as a whole food?
The "whole" story is not always published and most often leaves more questions than answered.
Individual supplements whether derived from whole foods or not are not as effective as eating a whole food even if the total sum of that supplement in the food is MUCH less than the isolated supplement. The whole food works synergistically and feeds the body... the body must expend energy to use an isolated supplement and may cause an energy deficit. In the end the whole food may in fact be a better source of the nutrient as it becomes more bio-available through the synergistic action of the whole.