Foods to Avoid
Hypothyroidism can be a tricky condition to manage, and what you eat can interfere with your treatment. Some nutrients heavily influence the function of the thyroid gland, and certain foods can inhibit your body’s ability to absorb the replacement hormones you may take as part of your thyroid treatment. There’s no such thing as a “hypothyroidism diet” that will make you well, but eating smart can help you feel better despite the condition. Here are nine foods to limit or avoid as you manage hypothyroidism:
The hormone estrogen can interfere with your body’s ability to use thyroid hormone, says Stephanie Lee, MD, PhD associate chief of endocrinology, nutrition, and diabetes at Boston Medical Center and an associate professor at the Boston University School of Medicine. Soy is loaded with plant-based phytoestrogen, and some researchers believe too much soy may increase a person’s risk for hypothyroidism. People with hypothyroidism should moderate their intake of soy. However, because soy hasn’t been definitively linked to hypothyroidism, there are no specific dietary guidelines.
Cruciferous vegetables, such as broccoli and cabbage, can interfere with the production of thyroid hormone, particularly people who have an iodine deficiency. Digesting these vegetables can block the thyroid’s ability to absorb iodine, which is essential for normal thyroid function. People with hypothyroidism may want to limit their intake of broccoli, Brussels sprouts, cabbage, cauliflower, kale, turnips, and bok choy. Cooking the vegetables can reduce the effect that cruciferous vegetables have on the thyroid gland. Limiting your intake to 5 ounces a day appears to have no adverse effect on thyroid function.
People with hypothyroidism may want to consider minimizing their intake of gluten, a protein found in foods processed from wheat, barley, rye, and other grains, says Ruth Frechman, RDN, a dietitian and nutritionist in the Los Angeles area and a spokesperson for the Academy of Nutrition and Dietetics. Gluten can irritate the small intestine and may hamper absorption of thyroid hormone replacement medication.
However, if you do choose to eat gluten, be sure to choose whole-grains varieties of bread, pasta, and rice, which are high in fiber and other nutrients and can help improve bowel irregularity, a common symptom of hypothyroidism. Also be sure to take your hypothyroidism medication several hours before or after eating high-fiber foods to prevent them from interfering with the absorption of your synthetic thyroid hormone.