Jenny had a thyroid problem and had been taking thyroxin for years. When her office connected with the Internet, she went online to a thyroid site. There she learned that soy was a potent thyroid depressant and should not be consumed by anyone with thyroid troubles. Next trip to the grocery store, she began to read labels and discovered that every load of bread in the supermarket contained soy flour.
“Thyroid enlargement in rats and humans, especially children and women, des with soy beans has been known for half a century,” according to Theodore Kay at Kyoto University in Japan. His 1988 study attempted to determine the amount of iodine required to prevent goiter in populations consuming soy foods. He found that small amounts of iodine could indeed prevent noticeable thyroid enlargement, but even large amounts did not prevent pathological changes to the thyroid gland. He also determined that the most potent goitrogens is soy cannot be removed by cooking.
Although scientists have known for many years that soy is goitrogenic, it was only recently that they were able to pinpoint the actual thyroid-depressing compounds. Researchers at the U.S. Toxicological Laboratory in Arkansas found that the thyroid-depressing substances are isoflavones, the estrogen-like compounds found plentifully in the soybean.
This discovery came as a shock to the soy industry, which has heavily promoted these phytoestrogens as beneficial.
From “Soy: The Dark Side of America’s Favorite: health” Food,” Well Being Journal, Vol. 16, No.4, www.wellbeingjournal.xom or 1-775-887-1702
A swelling of the neck resulting from enlargement of the thyroid gland.