Processed Foods
Cutting down on your consumption of processed foods can help prevent your hypothyroidism from worsening. Processed foods often contain a lot of sodium, and sodium is not good for people with underactive thyroids.
If you have to eat processed foods, always go for those with the lowest amounts of sodium.
Soy-Rich Foods
Avoid soy-based foods if you have hypothyroidism. These foods include tofu, miso, edamame, tempeh, and soy milk. This is because soy contains high amounts of isoflavones compared with other foods. Isoflavone is thought to negatively impact hormone production in the thyroid gland.
In a 2017 case study, a 72-year-old woman developed hypothyroidism after steadily consuming a health drink high in soy for about six months. [13] Her condition only became better after she stopped taking the soy drink and began using thyroid hormone replacement medicines.
Another paper found that soy consumption interfered with the body’s ability to absorb thyroid hormone replacement medication. [14]
More research is needed to ascertain the exact impact of soy on thyroid function. Contrary to the previous reports, a paper published in 2019 found that soy did not affect thyroid hormones and only slightly raised thyroid-stimulating hormone (TSH) levels. [15]