9 Foods to Avoid if You’re Diagnosed With Hypothyroidism
What you eat can affect your thyroid gland as well as your body’s ability to use thyroid hormone. Learn which foods to avoid when managing hypothyroidism.
Certain foods like fatty meat and cruciferous veggies may interfere with the production of thyroid hormone.
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.
Having a thyroid condition is no picnic, but you're not alone with this health issue. According to the American Thyroid Association, more than 12 percent of the population may end up dealing with a thyroid condition at some point in their lives. And thyroid issues can be sneaky: Of the nearly 20 million Americans living with the disease, as many as 60 percent don't even realize they have it.
As with many health conditions, some factors are out of your control, including your family history and the environment around you. But diet also plays a prominent role — and since you're the one in charge of your plate, you can decide which thyroid-friendly foods to choose.
Some items on this list may strike you as odd, like fiber and coffee, because for many other diets they're considered 'healthy' or ‘safe’ picks. You can still enjoy these foods groups, but moderating your intake is a good idea when managing hypothyroidism.
But many of the others to watch out for already fall into the no-no category as part of a smart diet, so skipping them, or at least cutting way back, is definitely a no-brainer. These include fried fast-food meals, salty processed foods, sugary treats, such as pastry, cake, cookies, and ice cream, and excessive alcohol.
So while there's no such thing as a "hypothyroidism diet" that will make you well, eating smart can help you feel better despite the condition. Here are nine foods to limit or avoid as you manage hypothyroidism:
Foods With Soy, Including Edamame, Tofu, and Miso
There’s long been concern over the potential negative effects that certain compounds in soy — called isoflavones — may have on the thyroid. Some researchers believe that too much soy may increase a person's risk for hypothyroidism. A study published in March 2019 in Scientific Reports, however, found that soy has no effect on thyroid hormones and very modestly raises thyroid stimulating hormone levels.
So there are no specific dietary guidelines, but some research does suggest that consumption of soy may interfere with your ability to absorb thyroid medication. For that reason, you may want to wait four hours after eating soy-based foods before taking your regular dose. Check with your doctor to see what’s best for you.
Cruciferous Vegetables Like Broccoli and Cauliflower
Cruciferous vegetables, such as broccoli and cabbage, are full of fiber and other nutrients, but they may interfere with the production of thyroid hormone if you have an iodine deficiency. So if you do, it’s a good idea to limit your intake of Brussels sprouts, cabbage, cauliflower, kale, turnips, and bok choy, because research suggests digesting these vegetables may block the thyroid's ability to utilize iodine, which is essential for normal thyroid function. However, according to the Mayo Clinic, you would need to consume a significant amount of cruciferous vegetables for it to truly impact iodine uptake.
If you have been diagnosed with both hypothyroidism and iodine deficiency, there are some things you can do to make these vegetables less harmful. Cooking them can reduce the effect that cruciferous vegetables have on the thyroid gland, and limiting your intake of these (cooked) vegetables to 5 ounces a day may help as well, since that amount appears to have no adverse effect on thyroid function.
Gluten, Found in Bread and Pasta
Those 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 in the Los Angeles area and a spokesperson for the Academy of Nutrition and Dietetics. And if you have been diagnosed with celiac disease, gluten can irritate the small intestine and may hamper absorption of thyroid hormone replacement medication.
An article published in May 2017 in the journal Endocrine Connections noted that hypothyroidism and celiac disease are often present together, and while no research has demonstrated that a gluten-free diet can treat thyroid conditions, you may still want to talk to a doctor about whether it would be worth eliminating gluten, or getting tested for celiac disease. A study published in July 2019 in Experimental and Clinical Endocrinology & Diabetes found that a gluten-free diet may have clinical benefits for women with thyroid disease.
If you do choose to eat gluten, be sure to choose whole-grain varieties of bread and pasta, 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.
Fatty Foods Such as Butter, Meat, and All Things Fried
Fats have been found to disrupt the body's ability to absorb thyroid hormone replacement medicines, 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 in Massachusetts.
Fats may also interfere with the thyroid's ability to produce hormone as well. Some healthcare professionals recommend that you cut out all fried foods and reduce your intake of fats from sources such as butter, mayonnaise, margarine, and fatty cuts of meat.
Sugary Foods Like This Delicious Chocolate Cake
Hypothyroidism can cause the body's metabolism to slow down, Frechman says. That means it's easy to put on pounds if you aren't careful. "You want to avoid foods with excess amounts of sugar because it's a lot of calories with no nutrients," she says. It's best to reduce the amount of sugar you eat or try to eliminate it completely from your diet.
Processed Foods in Packages and the Frozen Aisle
"Processed foods tend to have a lot of sodium, and people with hypothyroidism should avoid sodium," Frechman says. Having an underactive thyroid increases a person's risk for high blood pressure, and too much sodium further increases this risk.
Read the "Nutrition Facts" label on the packaging of processed foods to find options lowest in sodium. People with an increased risk for high blood pressure should restrict their sodium intake to 1,500 milligrams a day, according to the American Heart Association.
Excess Fiber From Beans, Legumes, and Vegetables
Getting enough fiber is good for you, but too much can complicate your hypothyroidism treatment. The government's Daily Guidelines for Americans currently recommends that adults up to age 50 should take in 25 to 38 grams of fiber a day. Amounts of dietary fiber from whole grains, vegetables, fruits, beans, and legumes that go above that level affect your digestive system and can interfere with absorption of thyroid hormone replacement drugs.
If you're on a high-fiber diet, ask your doctor if you need a higher dose of thyroid medication. Your maintenance dose may need to be increased if you aren't absorbing enough medication.
Coffee: Time Your First Cup Carefully in the Morning
Per a study in the journal Thyroid, caffeine has been found to block absorption of thyroid hormone replacement. "People who were taking their thyroid medication with their morning coffee had uncontrollable thyroid levels, and we couldn't figure it out," says Dr. Lee. "I now have to be very careful to tell people, 'Only take your medication with water.'" You should wait at least 30 minutes after taking your medication before having a cup of joe.
Alcohol Doesn’t Play Well With Your Thyroid
Alcohol consumption can wreak havoc on both thyroid hormone levels in the body and the ability of the thyroid to produce hormone, according to a study in the Indian Journal of Endocrinology and Metabolism. Alcohol appears to have a toxic effect on the thyroid gland and suppresses the ability of the body to use thyroid hormone. Ideally, people with hypothyroidism should cut out alcohol completely or drink in careful moderation.
An earlier version of this article incorrectly stated that rice contains gluten. It does not. Everyday Health regrets the error.