THYROID and SOY, A CASE REPORT
A middle aged patient of mine with hyperthroidism consulted me regarding my recommendations for therapy. Since she had been on anti-thyroid medication for quite some time, the question about surgery or radioactive iodine therapy came up. Although her symptoms were much better controlled on the medication (Tapezole), the drug therapy did have potential negative effects in the future, and I felt that the patient should have the radioactive iodine therapy to kill off enough native thyroid tissue to eliminate the problem permanently. She had the procedure done, which amounted to taking some radioactive iodine orally. But part of the protocol is that she had to stop her Tapezole. As a result, within a matter of just a few days, all her thyroid symptoms came back again, including a swelling of both legs and feet. This is a relatively unusual manifestation of hyperthyroidism.

Due to the fact that our main nutrient company was just introducing an anti-thyroid herbal blend with Lycopus, I started her on that until enough time could pass when we could have her resume the medication which had been effective. Eventually that would be discontinued once the radioactive iodine had finished its work. Furthermore, I got some feedback from a patient who was quite convinced that soy in fact did block the thyroid hormones, despite my recent article to the contrary.

Apparently there is a foundation that is strongly against the use of soy as a food supplement, and they have promoted some articles on the subject which say soy blocks the thyroid. Since I am an open minded person, I saw an opportunity here. IF soy is a potent blocker of the production of thyroid hormone in the body, then a soy based product with the active ingredient (isoflavones) should help my current patient feel better. She was willing to delay resumption of her Tapezole for the good of science, and to further my education, so I put her on a soy supplement as well as the Lycopus product. Guess what happened? Nothing. That's right, the soy did not help at all. I am a pragmatist.

Yes I read the studies, and I noted the speculated evils of soy (there were a ton of them). But in the real world, does soy block thyroid hormone synthesis, or replacement therapy, or absorption of the hormone? No, it sure doesn't look like it. And that's not just based on this one case, although this one was a perfect test case. I have monitored patients on and off thyroid medication for 26 years, and have never found evidence of a blocking action. Sure it can cause goiters in rodents. Is soy milk bad for baby humans? I doubt it. And even if it did block the thyroid slightly, we still need a good alternative to cows milk formulas to treat at- risk babies with dairy allergy. I'm not sure I understand the heated emotionalism of this soy debate. I also wonder whether the dairy industry may have had something to do with creating the controversy.