Check the references listed for the article from Brain.com - there's a number of them reflecting studies in adults. If memory serves, there's been a large study of elderly men showing a reduction in cognitive function of those who consumed a lot of soy products.

I completely agree that there's big money on each side, but for sure the pitch of soy has been bent to it's advantage. A lot of people associate soy with Asian diets. Not really so - from what I understand, it's a story similar to grains - not until the advent of modern agriculture and food processing has soy been a staple of Asian diets.