Along with the increasing presence of soy foods in grocery stores and on restaurant menus has come increasing controversy over soybeans and thyroid health. We’re not surprised to find strong conflicting opinions in this area because scientific research on thyroid and soy is both complicated and inconclusive. Here’s what we know – and what we don’t know – about this important issue.
Soy Isoflavones and Thyroid Function
Research on soybeans and thyroid health has focused on one specific category of nutrient found in soybeans: isoflavones. Isoflavones are phytonutrients that belong to the much larger phytonutrient family called flavonoids. (Most foods contain flavonoids, and many vegetables are especially rich in this family of phytonutrients.) The best studied isoflavones in soybeans are genistein, daidzein, malonylgenistin, and malonyldaidzin. It is very clear that at a molecular and biochemical level, isoflavones in soy have the ability to change thyroid cell events in at least two ways that might be interpreted as posing a risk to the thyroid’s health.
Read more about this at WHFoods.org