Hypothyroidism is generally treated with synthetic thyroid hormone — and soy has long been thought to interfere with the body’s ability to absorb the medication. However, there’s no evidence that people who have hypothyroidism should avoid soy completely.

How much soy is bad for thyroid?

Can soy worsen your hypothyroidism? Research by the American Institute of Cancer Research shows that up to three servings of soy a day is thought to be safe.

Does soy raise TSH?

“The chances of having a high TSH were quadrupled in those who ate, on average, just under two servings a day [of soy foods] compared to those who didn’t eat any,” says study leader Serena Tonstad, MD, PhD, professor of public health at Loma Linda and a preventive cardiology physician in Norway.