Question by Eileen Ruski

Soy contains naturally-occurring estrogenic compounds (known as "phytoestrogens"). These chemicals do mimic estrogen in the body, so many scientists and others have raised concerns about possible effects in babies and young children. Phytoestrogens are interesting chemicals because they are readily metabolized and excreted from the body, and there is some evidence that they may have beneficial effects in some populations (such as adult women), since they may modulate the levels of estrogens in our bodies. Babies and young children, however, aren't supposed to have a lot of estrogen in their bodies, so there is more concern about these age groups. Honestly, however, I'm more worried about babies than about older children, since babies are in an especially delicate phase of rapid physical development. 
 
I advise against the use of soy infant formula. Breastfeeding is best anyway, and the amount of phytoestrogens in soy formula is quite hefty. Also, soy formula contains high levels of manganese, which is a neurotoxic metal.  
 
Once children are older and eating foods, I don't see a reason to steer clear of soy, but I also don't recommend eating huge amounts of it. It's fine to have soy as a part of a varied and balanced diet that also includes lots of fruits, vegetables, grains, and other foods. Like everything else, it's best to diversify, and to take everything in moderation!