Soy & Thyroid Disease

Soy-based products have increased in popularity in recent years. Used in foods ranging from milk to hot dogs, soy is seen by many health-conscious individuals as the best alternative to consuming animal products. At the same time, however, there has been speculation that soy is a direct link to an increase in cases of thyroid disease.

The Facts

• Soy comes from the soybean plant, a legume originally from eastern parts of Asia. Vegetarians often opt for products that are soy-based, since soy naturally contains protein. Soy is also seen as a better alternative than consuming meat, since it is plant-based and free of hormones that some animal products can contain. Soy milk and snacks, such as granola bars, have increased in popularity for those who are attempting to live in a healthier way.

Significance

• During the years that soy has become more popular, cases of thyroid disease have increased as well. There is speculation that soy consumption and thyroid disease may be related. When soy is consumed, it acts like a hormone. Soy contains goitrogens, which are substances that can disrupt thyroid function by suppressing iodine in the body. In rare cases, this can result in the swelling of the thyroid gland. However, soy also contains isoflavones that act in the body as antioxidants, but have also shown in some studies to prevent the thyroid from working normally.

Considerations

• In healthy adults, the maximum amount of isoflavones that can be consumed before adversely impacting the thyroid is 30 mg. Those who have thyroid disease and are taking medication already have a barrier against such radicals that can disrupt the thyroid, so keeping soy completely off-limits is questionable.

Misconceptions

• With the buzz about soy and thyroid disease possibly being linked, there are a number of questions and concerns. Some thyroid health advocates claim that it is best not to consume any thyroid products, and that companies who are selling soy-based products are, in essence, lying to the consumer. There is even concern over soy-based formula for infants. However, since these concerns have come to light, there has been no overwhelming evidence to prove that thyroid disease is directly related to the consumption of soy.

Prevention/Solution

• Any type of food consumed in moderation is healthy. Hence, soy has been proven to be good for one's health, but may cause problems if it is consumed in massive amounts every day. One way to offset an over-consumption of soy is to consume iodine, which can be found in a supplement, or simply by eating iodized salt with other foods. Those with an existing thyroid condition should check with their doctor about the appropriate amount of soy consumption. However, if thyroid disease sufferers are taking a medication, such as synthroid, this may not be an issue anyway, since the medicine is taken on an empty stomach in the mornings and works to offset any interference to the thyroid gland.