Which foods should you avoid while taking methimazole? (3+)

In this article, we will discuss which foods should be avoided while taking methimazole. We will also share what foods should be consumed while taking methimazole and other relevant information. 

Which foods should you avoid while taking methimazole? 

You should avoid excessive consumption of the following foods while taking methimazole: 

• iodine-rich foods
• cruciferous vegetables
• soy products
• caffeine 

The sources of these foods are as follows: 

Although these foods do not specifically interact with methimazole, research indicates that these foods should be avoided while taking antithyroid medications. Antithyroid medications are taken for hyperthyroidism. 

Hyperthyroidism occurs when your body produces excessive thyroid hormones. Methimazole is an antithyroid medication used to treat conditions like Grave’s disease, toxic multinodular goiter, and thyrotoxicosis (1). 

Methimazole can also be used to treat hyperthyroidism induced by medications. Medications like Celexa can influence thyroid function. Certain foods can also influence thyroid function and thus should be avoided while taking methimazole.

Now let’s discuss why these foods should be avoided while taking methimazole: 

Iodine-rich foods: 

Iodine plays an important role in the body in the synthesis of thyroid hormones. Excess of iodine can result in both hyperthyroidism and hypothyroidism as the relationship of iodine with thyroid hormones is complex (2). 

Thus, the intake of high amounts of iodine-rich foods is discouraged as it can counteract the effects of methimazole. Do not take iodine supplementation while taking methimazole without the approval of your healthcare provider. 

Cruciferous vegetables: 

Animal studies with cruciferous vegetables have shown that these vegetables contain compounds known as goitrogens which can result in hypothyroidism (2).

However, human studies have not shown any effect of these vegetables on thyroid function. Research indicates that moderate consumption of these vegetables in cooked form is safe for patients with hyperthyroidism (2). 

Due to the presence of goitrogens and results from animal studies, it is suggested that consuming raw cruciferous vegetables in large amounts should be avoided by patients with hyperthyroidism and while taking methimazole. 

Soy products: 

Soy products contain several compounds that are known to influence thyroid function. Multiple studies have explored this effect and shown an association between the occurrence of goiter and hypothyroidism and soy products (2). 

Research indicates that excessive consumption of soy products can cause hypothyroidism in individuals who also have iodine deficiency (2). 

Due to the possible impact of soy products on thyroid function, it is advised that excessive consumption should be avoided while taking methimazole as it can interfere with the therapeutic effects. 

Caffeine: 

Caffeine does not directly interact with methimazole. If you are taking methimazole, it means that you have hyperthyroidism. Avoiding caffeine is recommended because it can worsen the symptoms of hyperthyroidism.

Caffeine can cause sleep disturbances, anxiety, and nervousness which are also the symptoms of hyperthyroidism (3). Thus, to achieve the maximum therapeutic effects of methimazole, it is better to avoid caffeine consumption. 

What are other dietary considerations while taking methimazole? 

While taking methimazole, some other dietary modifications are also recommended in the literature. Gluten is considered to be pro-inflammatory and can cause inflammation in healthy individuals along with those with celiac disease. 

Celiac disease can co-occur with hyperthyroidism. A gluten-free diet is recommended for such individuals. Whether or not avoiding gluten is helpful with hyperthyroidism alone is still an area of research (4). 

Thus, avoiding gluten-rich foods or their excessive consumption can be helpful with hyperthyroidism and enhance the effects of methimazole. 

Which foods to take while taking methimazole? 

Consuming foods that are beneficial for hyperthyroidism may enhance the therapeutic effects of methimazole. The following minerals are associated with improving thyroid function (5): 

• iron
• selenium
• zinc
• vitamin B12
• vitamin D3

These minerals may support your treatment of hyperthyroidism while taking methimazole. However, you should not take any supplements without consulting your healthcare provider. 

In my experience:

As per my understanding, you should avoid excessive consumption of iodine-rich foods, cruciferous vegetables, caffeine, and soy products while taking methimazole. 

These foods do not interact with methimazole but influence thyroid function which may counteract the therapeutic effects of methimazole. Research also suggests that reducing gluten intake can improve hyperthyroidism. 

Several minerals can help to improve thyroid function. However, no supplements should be taken without the guidance of a healthcare provider while taking methimazole.  

References