What food is bad for thyroid

Drinking alcohol can worsen the thyroid functioning

Hypothyroidism is a disorder in, which the thyroid gland is unable to make enough of the hormones it's expected to produce. A few of the most common symptoms of hypothyroidism are weight gain, lethargy, poor memory/ forgetfulness, hoarse voice, drying of hair, etc. Living with thyroid can be difficult and certain foods might worsen the condition. Here are some food groups you should avoid if you are a thyroid patient:

Processed foods: Processed foods include packaged pre-cooked foods (potato chips, wafers, etc.), cooked frozen foods (fries, chicken nuggets, etc.), and so on. Majority of the processed foods contain high levels of sodium and people that suffer from thyroid are advised to avoid or reduce the consumption of sodium. A high-sodium diet has proven to increase blood pressure in average human beings, this is worse for people suffering from thyroid.

Cruciferous vegetables: Cruciferous vegetables are mostly the green leafy vegetables. These include cauliflower, kale, lettuce, broccoli, Brussels sprouts, cabbage, and so on. Although cruciferous vegetables are full of nutrents, studies have found that the body might have trouble utilising iodine in case it is consuming any of these vegetables. Hence, we advise you to consume only a limited amount of cruciferous vegetables. 

Soybeans and their products: Soybeans and their products such as tofu, edamame, miso, etc. have proven to contain compounds called isoflavones. Isoflavones might increase your chances of getting thyroid. In case you do suffer from thyroid, these products might nullify the effect of your thyroid medication. 

Gluten: experts suggest foods that contain the protein gluten (wheat, rye, barley) should be avoided by thyroid patients. Gluten has been proven to reduce the effect of thyroid medication. Furthermore, many people that suffer from thyroid also have celiac disease, which requires the patient to give up gluten completely. 

Foods high in fats: Although the body does require some healthy fats, unhealthy fatty foods can poorly affect the health of thyroid patients. Fatty foods would include fried foods, meat, certain dairy products, and so on. Fats have been proven to reduce the absorption of thyroid medication by the body.

High-fibre foods: some of the most common high-fibre foods are beans, legumes, bread, vegetables, and so on. High-fibre foods are known to overwork the digestive system as they take longer to break down. This may even affect the effects of thyroid medication on the body. In fact, in case you consume a high-fibre diet, you may have to ask your doctor to increase your thyroid medication to increase its effectiveness. 

Alcohol: Drinking alcohol has various negative effects on the body, one of which is worsening thyroid. For thyroid patients, doctors suggest reducing the consumption of alcohol to almost zero. Alcohol can have adverse effects on the levels of hormones the thyroid produces. Furthermore, excess alcohol consumption can restrict the body from using thyroid hormones.

In conclusion, some of the healthier known foods can also have adverse effects on your health as well as medication. To keep your symptoms manageable and medications effective, we advise you to thoroughly research what foods are to be consumed and avoided.

Disclaimer: This content including advice provides generic information only. It is in no way a substitute for qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.

People with thyroid conditions can’t manage their condition through diet. But, eating the wrong foods or taking the wrong supplements can cause trouble.

Among the foods to go easy on are soy, kelp and dietary supplements like iodine and selenium, says endocrinologist Christian Nasr, MD. “There is a lot of literature on what people shouldn’t do,” he says.

Should people with thyroid problems avoid these foods?

Soy: If you have hypothyroidism, yes. Eating too much soy causes problems only for those with hypothyroidism, which occurs when your thyroid gland does not make enough thyroid hormones, Dr. Nasr says.

The main problem is that soy may hinder absorption of the hormones that such patients take.

“Some studies show that if you eat a lot of soy, or drink a big glass of soy milk, within one hour of taking a thyroid hormone, it might affect absorption,” Dr. Nasr says. “Many individuals depend on a consistent absorption of those hormones to achieve a steady state.”

Generally, experts recommend that people who have a borderline thyroid — one that’s a little underactive but you’re still trying to preserve thyroid function — do not to consume large amounts of soy every day, he adds.

Turnips and root vegetables: No. These vegetables are sometimes thought to cause thyroid problems, but that’s not the case, Dr. Nasr says. They are good for your diet, regardless of any thyroid issues.

One root vegetable that is the exception is cassava, a common staple in certain parts of Africa. This plant “is known to produce toxins that can slow an already underactive thyroid, especially in the presence of an iodine deficiency,” Dr. Nasr says. “But that’s not relevant here in the United States, unless you cook cassava and you eat it every day.”

Kelp: No, but don’t take it in supplement form. People with thyroid issues should not have more than an average daily recommended intake of 158 to 175 micrograms of kelp per day, Dr. Nasr says. The concentration of kelp in foods is generally not enough to cause a problem, but a kelp capsule can contain as much as 500 micrograms, he says. “Those recommendations to go easy on kelp are for people who don’t understand and take three capsules per day. If you eat an average amount of kelp once a day, that’s not a problem.” Pregnant women especially should avoid ingesting large amounts of kelp, as it may put them at risk for developing fetal goiter, he adds.

Cabbage and cruciferous veggies: Yes. Even though they are good for us, cabbage and other cruciferous vegetables eaten raw in large quantities, especially in the context of iodine deficiency or borderline iodine levels, can result in hypothyroidism. These vegetables generate a substance that competes with the uptake of iodine by the thyroid.

Should people with thyroid problems avoid these supplements?

Iodine: Yes. Avoid it as a supplement whether you have hyperthyroidism or hypothyroidism. The effect of iodine supplements can vary by person, causing the thyroid to produce either too much or too little hormone.

Certain alternative medicine websites or doctors tell patients that iodine is good for your thyroid, Dr. Nasr says, but “if there is anybody who shouldn’t take iodine, it is thyroid patients.” Such claims are made because iodine deficiency is the No. 1 cause of thyroid conditions in the world, he says. But that’s not true in the U.S., where we have iodine in our diets. Iodine is added to many foods, and not just salt, he says.

However, Dr. Nasr says that people on restrictive diets may consider adding a daily multivitamin that contains the recommended daily allowance of iodine.

He also assures patients not to worry that you are getting too much iodine from everyday foods. “You would have to eat a ton of it to cause problems,” he says. “It’s not, ‘don’t eat anything with iodine.’ It’s, ‘don’t eat a bunch of iodine.’ And patients should be careful with iodine-concentrated supplements.”

Selenium: No, but don’t take more than 200 micrograms per day. Selenium, which is needed to support efficient thyroid function, is not something you would typically find at the grocery store, but an alternative medicine doctor might prescribe it, Dr. Nasr says. You can also get it in foods like fish, Brazil nuts, meat and poultry. A selenium supplement is OK to use “as long as you’re not overdoing it,” he says.

Related Articles

Below, learn about how the diet can affect hypothyroidism symptoms. We also suggest specific foods to eat and avoid and provide a 1-week meal plan.

Share on PinterestHours/Getty Images

Having hypothyroidism means that the body does not have enough thyroid hormones. While changing the diet cannot cure this, it can help manage the condition.

Starting off, it can help to know the following information:

• Foods that contain certain nutrients, such as iodine, selenium, and zinc, can help maintain healthy thyroid function.
• Some foods may negatively affect thyroid function and worsen symptoms of hypothyroidism.
• Some foods and supplements can interfere with how well the body absorbs thyroid replacement medicine, so limiting these can also help.

The body needs iodine to produce thyroid hormones. But because the body cannot make iodine, people need to get it from their diets.

Foods rich in iodine include:

• cheese
• milk
• iodized table salt
• saltwater fish
• seaweed
• whole eggs

Iodine deficiency is relatively uncommon in the United States, due to the wide use of iodized table salt, but it is prevalent in other areas.

A deficiency can cause an enlarged thyroid gland, known as a goiter.

However, it is crucial to avoid consuming too much iodine. This can actually worsen hypothyroidism, and it can also worsen hyperthyroidism, which refers to the body having excess thyroid hormones.

For this reason, a person should only add more iodine to their diet if a doctor recommends it.

Selenium is a micronutrient that plays a role in the production of thyroid hormones and has antioxidant activity. Thyroid tissue naturally contains it.

A 2017 review found that maintaining selenium levels in the body helps prevent thyroid disease and promotes overall health.

Foods rich in selenium include:

• Brazil nuts
• tuna
• shrimp
• beef
• turkey
• chicken
• ham
• eggs
• oatmeal
• brown rice

Zinc is another nutrient that may specifically benefit people with low levels of thyroid hormones.

One small-scale study showed that zinc supplementation, alone or in combination with selenium supplementation, improved thyroid function in females with hypothyroidism.

Foods rich in zinc include:

• oysters
• beef
• crab
• fortified cereals
• pork
• chicken
• legumes
• pumpkin seeds
• yogurt

Certain nutrients can interfere with thyroid health. While foods rich in these nutrients are not off-limits, restricting the intake of these foods may help a person manage their hypothyroidism.

Goitrogens

Goitrogens are compounds that may affect thyroid function if a person consumes large amounts.However, in regular amounts, vegetables that contain goitrogens, such as broccoli and bok choy, are beneficial for overall health and do not interfere with thyroid function.

Plus, cooking the vegetables mostly deactivates the goitrogenic compounds.

Foods that contain goitrogens are typically green cruciferous vegetables, including:

• collards
• brussels sprouts
• Russian kale
• broccoli
• broccoli rabe
• cauliflower
• cabbage

Soy

Some evidence indicates that soy might interfere with how the body produces thyroid hormones.

In one case study, a 72-year-old female developed severe hypothyroidism after regularly consuming a soy-heavy health drink for 6 months. The person’s condition improved after they stopped drinking the beverage and started taking thyroid hormone replacement medication.

However, other research has found that soy has no significant effect on thyroid levels. Identifying the effects of soy on thyroid function requires more research.

Foods that contain soy include:

• soy milk
• soy sauce
• edamame
• tofu
• miso

Gluten

People with Hashimoto’s disease — a cause of hypothyroidism — are more likely to have celiac disease than the general population. This is because Hashimoto’s and celiac are both types of autoimmune disorder, and a person with one of these disorders is more likely to develop another.

Research also suggests that removing gluten from the diet improves thyroid function in people with Hashimoto’s who do not have celiac disease.

This disease causes chronic inflammation and damage to the small intestine due to the ingestion of gluten, a protein in wheat and other grains, including barley, oats, and rye.

Treating celiac disease involves switching to a gluten-free diet. People with autoimmune-related hypothyroidism might try going gluten-free to see whether their symptoms improve.

Processed foods

Reducing the intake of ultra-processed foods and added sugars may help improve symptoms, manage weight, and boost overall well-being.

Examples of ultra-processed foods and drinks that also contain high amounts of added sugar include:

• fast food
• hot dogs
• donuts
• cakes
• cookies
• soda

It is important to take thyroid medication on an empty stomach so that the body can absorb it fully. Take it at least 30–60 minutes before breakfast or at least 3–4 hours after dinner.

People should not take this medication within 4 hours of eating foods that contain iron or calcium.

Also, the following medications and supplements may interfere with the body’s absorption of thyroid medication:

• antacids or acid reducers
• milk and calcium supplements
• iron supplements
• high-fiber foods, such as bran flakes, fiber bars, and fiber drinks
• foods high in iodine
• soy-based foods

In general, the best diet for a person with hypothyroidism contains plenty of fruits, vegetables, filling proteins, healthy fats, and moderate amounts of healthy carbohydrates.

Still, it is important for each person to experiment and develop a diet that helps them feel their best.

Below, find a sample 1-week meal plan for an omnivorous person with hypothyroidism:

Monday

• Breakfast: Scrambled eggs with salmon
• Lunch: A salad with grilled shrimp
• Dinner: A black bean and vegetable stir-fry with brown rice

Tuesday

• Breakfast: A fruit salad with yogurt and sliced almonds
• Lunch: A grilled chicken salad topped with pumpkin seeds
• Dinner: Baked salmon with roasted vegetables

Wednesday

• Breakfast: An omelet with mushrooms and zucchini
• Lunch: Bean soup with a whole wheat or gluten-free roll.
• Dinner: Shrimp fajitas with corn tortillas, peppers, and onions

Thursday

• Breakfast: A protein smoothie with berries and nut butter
• Lunch: A cauliflower rice bowl with ground turkey, black beans, salsa, guacamole, cheese, and veggies
• Dinner: Roasted chicken with quinoa and broccoli

Friday

• Breakfast: Poached or boiled eggs with avocados and berries
• Lunch: Tuna salad lettuce cups with whole wheat or gluten-free crackers
• Dinner: A grilled steak with baked sweet potato and a side salad

Saturday

• Breakfast: Coconut yogurt with berries and almond butter
• Lunch: A turkey burger on a green salad with sweet potato fries
• Dinner: Pan-fried crab cakes with brown rice and vegetables

Sunday

• Breakfast: A frittata with vegetables
• Lunch: A quinoa bowl with vegetables and chickpeas
• Dinner: Grilled shrimp skewers with bell peppers and pineapple

People with hypothyroidism may gain weight more easily than people without the condition. This is because hypothyroidism can slow metabolism.

Having a healthy diet rich in fruits, vegetables, filling proteins, and healthy fats can help manage weight and boost well-being. These foods are also rich in fiber, which may help people feel fuller for longer.

In addition, regular moderate- to high-intensity aerobic exercise and strength training can help boost metabolism and promote weight loss. Staying active can also improve levels of energy and the quality of sleep.

In addition, a person may notice a small weight reduction — typically under 10% — when they take medication to treat hypothyroidism.

Hypothyroidism refers to the thyroid gland not producing enough of certain hormones to meet the body’s needs.

Untreated, it can reduce metabolism and cause fatigue, among other symptoms. Treatment usually involves taking a synthetic version of thyroid hormones.

Some nutrients and foods can help or hinder the thyroid’s function. Overall, it is important to aim for a healthy diet that supports the absorption of thyroid medication and helps with maintaining a healthy weight.

Last medically reviewed on November 7, 2021

Medical News Today has strict sourcing guidelines and draws only from peer-reviewed studies, academic research institutions, and medical journals and associations. We avoid using tertiary references. We link primary sources — including studies, scientific references, and statistics — within each article and also list them in the resources section at the bottom of our articles. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

• Eghtedari, B., et al. (2021). Levothyroxine.
  //www.ncbi.nlm.nih.gov/books/NBK539808/
• Felker, P., et al. (2016). Concentrations of thiocyanate and goitrin in human plasma, their precursor concentrations in brassica vegetables, and associated potential risk for hypothyroidism.
  //www.ncbi.nlm.nih.gov/pmc/articles/PMC4892312/
• Hashimoto's disease. (2021).
  //www.niddk.nih.gov/health-information/endocrine-diseases/hashimotos-disease
• Hypothyroidism (underactive thyroid). (2021).
  //www.niddk.nih.gov/health-information/endocrine-diseases/hypothyroidism
• Iodine deficiency. (n.d.).
  //www.thyroid.org/iodine-deficiency/
• Krysiak, R., et al. (2019). The effect of gluten-free diet on thyroid autoimmunity in drug-naive women with Hashimoto's thyroiditis: A pilot study [Abstract].
  //pubmed.ncbi.nlm.nih.gov/30060266/
• Mahmoodianfard, S., et al. (2015). Effects of zinc and selenium supplementation on thyroid function in overweight and obese hypothyroid female patients: A randomized double-blind controlled trial.
  //www.ncbi.nlm.nih.gov/pubmed/25758370
• McMillan, M., et al. (2016). Comorbidities, concomitant medications, and diet as factors affecting levothyroxine therapy: Results of the CONTROL Surveillance Project.
  //www.ncbi.nlm.nih.gov/pmc/articles/PMC4767717/
• Nakamura, Y., et al. (2017). Soy isoflavones inducing overt hypothyroidism in a patient with chronic lymphocytic thyroiditis: A case report.
  //www.ncbi.nlm.nih.gov/pmc/articles/PMC5583972/
• Otun, J., et al. (2019). Systematic review and meta-analysis on the effect of soy on thyroid function.
  //www.nature.com/articles/s41598-019-40647-x
• Roy, A., et al. (2016). Prevalence of celiac disease in patients with autoimmune thyroid disease: A meta-analysis [Abstract].
  //pubmed.ncbi.nlm.nih.gov/27256300/
• Selenium. (2021).
  //ods.od.nih.gov/factsheets/Selenium-HealthProfessional/
• Soy allergy. (n.d.).
  //www.foodallergy.org/common-allergens/soy-allergy
• Thyroid and weight. (n.d.).
  //www.thyroid.org/thyroid-and-weight/
• Ventura, M., et al. (2017). Selenium and thyroid disease: From pathophysiology to treatment.
  //www.hindawi.com/journals/ije/2017/1297658/
• Zinc. (2021).
  //ods.od.nih.gov/factsheets/Zinc-HealthProfessional/