I had been using whey protein in December, and then switched to soy after I used up the whey bc of the benefits soy might offer me with cholesterol reduction, etc. So then I noticed my asthma kicked in really bad and I thought I had picked up dd's cold. One month later, I'm still hacking lungs up in my coughs and very phlegmmy/mucousy in the lungs. Hmmm, it occurred to me that soy could be causing the same reaction dairy does in people like me who get congestion coughs from milk. My daughter came up allergic to soy in a test she had, and we know the apple doesn't fall far from the tree in genetics. So, after a week off soy, my cough is miraculously better, the phlegm is much less, and I'm not using my inhalers. So it sounds like a no brainer, but I'm just curious if anyone else has heard of this. A google search did not pull this up as a reaction to soy. More common is the gastro issues and rashing.

I am not asthmatic, but I find that the soy powder causes bloating and stomach cramps if eaten uncooked. Soy protein powder is generally hard to digest. I can eat it in a dish that is cooked; example, I add it to pancake mix to stretch out the protein. For protein drinks, I stick to whey protein which is easily and quickly digested.

I've heard about the gastro problems, rashes, and bloating, but if you are really allergic, it could manifest that way.