Key Takeaways

  • It’s usually not possible to manage hyperthyroidism with diet alone. However, certain dietary changes may help to reduce symptoms or prevent complications.
  • Avoiding caffeine and foods high in iodine may help those with Graves’ disease. Some people may also need to avoid soy before undergoing radioactive iodine treatment.
  • Talk with a doctor or registered dietitian for a personalized plan, and consider asking them about supplements to prevent deficiencies.

There’s no universal diet for all people with hyperthyroidism. This is because hyperthyroidism can have different causes and subtypes.

In the United States, most people with hyperthyroidism have an autoimmune condition known as Graves’ disease. Diet alone can’t manage Graves’ disease, although it may help with symptoms.

Read on to learn how food may help or hinder hyperthyroidism, or an overactive thyroid.

There is no specific diet for hyperthyroidism that will help everyone. Some people may not need to make any dietary changes. However, some people may need to reduce or increase certain nutrients.

Whether diet changes are necessary will depend on the type of hyperthyroidism you have, what treatments you’re undergoing, and how the condition specifically affects you.

Working with a doctor or dietitian may help you find a routine that reduces your symptoms.

Depending on your situation, a doctor may advise you to avoid or limit:

Excessive iodine

Iodine is an essential nutrient for thyroid function. It stimulates thyroid hormone production, which is beneficial in the right amounts.

In fact, a 2019 study in Denmark suggests that adequate iodine intake may reduce the risk of developing hyperthyroidism.

But if you have an autoimmune form of hyperthyroidism, getting too much iodine could worsen your symptoms.

Graves’ disease is the type of hyperthyroidism most people in the U.S. have. It’s an autoimmune condition, meaning the immune system is attacking a healthy part of your body.

A doctor may advise lowering, but not entirely avoiding, iodine if you have Graves’ disease. Foods that are high in iodine include:

  • seaweed
  • fish and seafood
  • iodized table salt

Caffeine

Foods and beverages that contain caffeine, such as coffee, tea, energy drinks, and chocolate, may exacerbate the symptoms of hyperthyroidism.

Caffeine can cause feelings of anxiety, nervousness, or an increased heart rate. It may also contribute to insomnia.

Avoiding or limiting your intake may help.

Soy

According to the British Thyroid Foundation, soy may interfere with radioactive iodine treatment, which is a potential treatment for hyperthyroidism.

A doctor may suggest avoiding soy products, including milks, protein powders, and tofu, before this treatment.

Gluten

There is some speculation that gluten may worsen Graves’ disease. A 2020 case study found that avoiding gluten resolved a woman’s symptoms after she received medical treatment.

However, there is insufficient evidence to show that gluten elimination would benefit a large population. More research is necessary.

If you have Graves’ disease, you may want to try reducing or avoiding gluten for a while to see if it helps, but remember to check the ingredients of gluten-free products for added iodine or seaweed.

Below are some nutrients and ingredients that may be especially beneficial for those with hyperthyroidism.

Selenium

Selenium is important for thyroid function. Good food sources of selenium include Brazil nuts, meats, spaghetti, oatmeal, mushrooms, and brown rice.

Be aware that too much selenium can be toxic. The recommended daily amount for adults is 55 micrograms (mcg).

Zinc

Some research has noted a possible link between zinc deficiency and Graves’ disease. Food sources of zinc include:

  • beef
  • chicken
  • legumes
  • mushrooms
  • pumpkin seeds

Calcium and vitamin D

Untreated hyperthyroidism can cause weak and brittle bones over time. In addition to treating the underlying condition, it’s important to get enough vitamin D and calcium to maintain healthy bones.

One of the best sources of calcium is dairy products. However, some calcium-rich foods may be high in iodine, which is an obstacle for some people. A dietitian can advise on ways around this.

For vitamin D, people can try:

  • oily fish
  • mushrooms grown under UV light
  • supplements, which may be necessary if you live in a cold climate or don’t get much light exposure

Anti-inflammatory foods

Eating a generally balanced, nutritious, and anti-inflammatory diet may help improve overall health and support thyroid function. The British Thyroid Foundation suggests a mix of:

  • fruits and vegetables
  • high fiber carbohydrates such as potatoes, rice, or other grains
  • fish, meat, eggs, pulses, or other protein
  • some dairy or dairy alternatives
  • unsaturated fats, such as olive oil or avocados

Avoid highly processed foods and added sugars.

In most cases, no, diet alone does not cure hyperthyroidism. This is because, in the U.S., 4 in 5 cases of hyperthyroidism happen due to Graves’ disease. Diet alone can’t treat this condition.

However, diet can be part of the treatment for iodine-induced hyperthyroidism (IIH). This type of hyperthyroidism is not common in the U.S., but it is possible.

There are two ways IIH can develop:

  • Too much iodine: High-dose iodine supplements, tinctures, iodized table salt, and seaweed are all abundant in iodine. Too many of these could push thyroid activity too far. Some medical scans also involve using iodine contrast dyes, which can cause hyperthyroidism for some people. Iodine can also be an ingredient in some cough syrups and medications.
  • Correction of an iodine deficiency: Conversely, if you live in a place where iodine-rich foods are scarce, you could develop hypothyroidism, or an underactive thyroid. Treating this could initially cause an overactive thyroid.

IIH is usually temporary, but it can require dietary changes if a specific food or supplement is causing the problem.

Sometimes, IIH also needs medical intervention, especially if someone has developed thyroid nodules.

High levels of thyroid hormones in your body can be toxic. Left untreated, hyperthyroidism may lead to heart problems, bone loss, fracture risk, and other issues.

Your doctor may prescribe antithyroid medications. These drugs help reduce the amount of hormone the thyroid gland produces. In some cases, treatment may include radiation therapy or thyroid surgery.

After treatment, it’s still important to balance iodine in your diet. Other foods help to protect your thyroid and reduce the long-term effects of hyperthyroidism.

If you have hyperthyroidism, it’s important to talk with your doctor or dietitian about making short-term and long-term changes to your diet. This can help balance thyroid function and protect your body from the effects of hyperthyroidism.

Some dietary restrictions can be temporary. Other dietary changes are part of a healthy, balanced lifestyle for better overall health.

If you’re on a low-iodine diet, it can be more difficult to get enough of some other nutrients. Talk with your doctor or dietitian about taking supplements for these nutrients.