How topical. I have an appointment on Friday with an endocrinologist to check for a bum thyroid.
I didn't know ANYTHING about any link between soy and thyroid issue until recently. I started getting hives out of the blue. Every single day. They were waking me up in the middle of the night. It was terrible. After evaluating my diet, the only thing I had been eating differently was WAY more processed soy foods since going from vegetarian to strict vegetarian a couple weeks earlier.
Besides meat analogues I was suddenly eating soy cheeses, soy ice cream, soy milk, etc. I thought maybe I was developing a soy allergy. So I took a short trip away from home to rule out a sudden allergy to my cat and I pounded soy to test my hypothesis. I figured if I got hives worse than normal I would have figured it out and I could go from there. Well, my hives were the same but my throat swelled up really bad! It scared the hell out of me. So, I concluded that I had a soy allergy and in the week afterward I cut soy completely. But the hives didn't go away. So I added a LITTLE bit of soy back to my diet - dressings, a sprinkle of soy parmesan, etc. A week or so ago I went out to a veg restaurant and couldn't resist the soy asada tacos. Within half an hour my throat was swelling again.
I came home and spent several hours googling my ass off and discovered that a) the thyroid is located in the exact spot my throat was swelling, b)chronic hives like I am experiencing are sometimes a sign of thyroid disease and c)that large quantitites of soy can trigger thyroid problems. I also learned that thyroid problems can result due to a lack of iodine and a lot of processed food do NOT have iodized salt in them, so if you're not using iodized table salt (I don't) you might be lacking in iodine. A patch test (where you draw an iodine circle on your arm and see how quickly it fades) seems to point to an iodine deficiency, but I don't know how reliable that is. A blood test indicates there might be aproblem with my thyroid so now I get to go to an endocrinologist and have more tests done to try and get this all figured out. Let me add that my mother and grandmother have thyroid problems so I'm predisposed. Some studies show that there is no relationship between soy and thyroid problems. All I know is that just a little bit of research and all of the pieces fell into place for me. I do not believe that soy CAUSED my problems. I think my family history and not enough iodine put me at risk and the large quantities of soy I began eating triggered an existing condition. I mean, I can't ignore that the gland actually SWELLED right after large quantities of soy were ingested. I think there is enough worry and evidence that it would justify some serious studies being done between processed soy and thyroid problems.
Some studies also show a link between animal proteins and an auto-immune disease of the thyroid called Hashimoto's disease, by the way.
P.S. The blood test I had done recently shows I am getting plenty of protein and iron, despite not eating animal products. Ha!