If you have a thyroid disorder, you know they can be extremely difficult to manage and that many things can affect that small butterfly-shaped gland. If you didn’t know, there are certain foods and other medications that can impact thyroid health and the effectiveness of thyroid medication. There are also deficiencies you should be tested for annually if you do have a thyroid disorder.
Let’s make sure you are doing all you can to manage your thyroid disorder effectively!
Foods that may negatively impact your thyroid health
1. Excessive intake of Goitrogens
Goitrogens are found in cruciferous veggies like cabbage, cauliflower, bok choy, broccoli and soy. It is possible for goitrogens to impact thyroid health when eaten raw and in extremely large amounts and/or in those with an iodine deficiency. This is because goitrin can interfere with the process of making thyroid hormones.
Too many goitrogens would look like eating 2.2-3 pounds of raw bok choy every day (as seen in a patient case study) or 4 to 5 large servings per day. If you are eating these foods once or twice a day in a ½-1 cup serving, you will be fine. Don’t feel like you have to avoid these foods—they are safe in moderation.
Millet isn’t often consumed in the typical American diet, but frequent consumption may decrease thyroid function, even in those with normal iodine stores. Eating small amounts of millet a few times a week should be safe, but consuming it multiple times a day might not be great for your thyroid. Make sure to read labels on whole grain and tempeh products to make sure you aren’t unknowingly consuming the grain.
Cassava is a root veggie hailing from the African culture that has started becoming trendy in the American food scene. However, if you have an underactive thyroid, frequent consumption may add stress to your thyroid. Eating this food occasionally in small amounts should be fine, but I would not recommend making it a daily staple.
Things that can interfere with your thyroid medication
You should always try to take thyroid medication an hour before or 3 hours after eating.
5. Fiber supplements
7. Lactose (dairy products)
Other drugs and supplements
Be sure and space four hours between thyroid medications and these medications and supplements listed below.
9. Calcium supplements or calcium-based medications
10. Chromium picolinate
12. Multivitamins with iron or iron supplements
13. Ulcer medications (Sucralfate)
14. Do not supplement with iodine
It’s important to keep in mind that certain nutrition deficiencies are more common among people with thyroid disorders. These include vitamin D, vitamin B12, selenium and iodine. Iodine in particular is really tricky to navigate. In those with thyroid disorders, iodine can be low or high. However, taking an iodine supplement (without your doctor’s recommendation) can impact your thyroid negatively. Do not start an iodine supplement without discussing with your doctor first.
15. High-dose flavonoid supplements
16. “Thyroid health” supplements
Thyroid support or thyroid health supplements are often dangerous because they contain animal thyroid hormones. According to the Mayo Clinic in 2011, 9 out of 10 thyroid support supplements were found to have risky amounts of animal thyroid hormones. High dose flavonoid supplements may also interfere with your thyroid function. Keep in mind that supplements aren’t regulated by the FDA and usually aren’t clinically tested. Supplement ingredients can often be incorrect or misleading as well.
Please talk with your doctor before starting any new supplements or if you have questions regarding thyroid medication. Learn more about treatment for thyroid disorders and other endocrine conditions here.
Nutrition-related questions on your mind? Find a registered dietitian today.
About the author
Alessandra Stasnopolis, RDN, LDN
Alessandra Stasnopolis, RDN, LDN, is a clinical dietitian and wellness coordinator in the Baylor Scott & White Health wellness department.