Too much water can do you damage too. Its probably more a matter of not overdoing it. I looked up a couple of the soy studies and alot of them are fairly shoddy. What i can gather from both sides of the arguement is that if you are healthy it can be a great food source. People, women in particular who are prone to hormone imbalance are better off not having soy to often as it can interfere with your hormones if your equilibrium is fragile. Individuals with fairly robust systems dont need to worry if its eaten in moderation. The studies that found big problems for soy eaters were testing people who were having soy as a very major part of their diet ie. 5-6 serves a day including soy milk etc. I would also try not to give young babies too much soy as their guts are still very under-developed and initally are only designed to process breast milk, I know this can sometimes be unavoidable.