3 myths around eating for hypothyroidism

There’s a lot of confusion around eating for hypothyroidism and Hashimoto’s, especially when it comes to goitrogens, iodine, and gluten-free foods. For example, many people believe goitrogenic foods (goitrogens) are harmful to the thyroid gland and should be avoided — but that eating an iodine-rich diet is necessary for thyroid health. In reality, neither is true. 

Another common myth is that all gluten-free diets are created equal. In reality, a whole-food, gluten-free diet is best for thyroid function and overall health — not a gluten-free diet consisting primarily of ultra-processed foods. Gluten is an issue for many individuals with hypothyroidism and Hashimoto’s thyroiditis, but ultra-processed foods can be just as problematic. 

Let’s take a closer look at these three common myths and dispel them once and for all. 

1. Goitrogens are harmful to the thyroid gland

One of the most common myths associated with eating for hypothyroidism is that goitrogenic foods (goitrogens) are harmful to the thyroid gland and should be avoided. These foods — which contain a natural component known as glucosinolates — include cruciferous vegetables like cauliflower, broccoli, kale, collard greens, and Brussels sprouts. 

Reality: Goitrogens are perfectly healthy for most people

While the glucosinolates in cruciferous veggies can inhibit the absorption of iodine and decrease thyroid hormone production (more on this in the next section), the risks are minimal. Especially in comparison to the many health benefits associated with consuming cruciferous vegetables, like protection against cancer, inflammation, oxidative stress, cardiovascular disease, and depression.

If you’re concerned about the potential adverse effects of consuming goitrogens — or you know you’re deficient in iodine — you can cook cruciferous vegetables before consuming them. Cruciferous vegetables are only goitrogenic when raw, so eating steamed or fermented crucifers isn’t an issue. 

2. An iodine-rich diet is necessary for thyroid function

There’s much confusion as to whether an iodine-rich diet is helpful or harmful to the thyroid gland. It’s true we need some iodine to support the function of the thyroid gland, but too much of it can cause the very issues we’re trying to avoid: hypothyroidism, Hashimoto’s disease, goitre, and elevated TSH. 

Reality: Excess iodine can be harmful

The thyroid gland requires about 150 mcg of iodine daily in order to function optimally. This can be obtained from supplements; iodized salt; and iodine-rich foods like seaweed, fish, beef liver, and chicken. Obtaining more than 450 mcg daily, however, can be harmful — especially among those with Hashimoto’s. 

Just two tablespoons of dried nori seaweed may contain about 116 mcg of iodine, while two slices of enriched white bread might contain upwards of 296 mcg of iodine. As you can see, it’s easy to overdo it if you’re not careful. One exception is if you’re vegan or vegetarian, as strictly plant-based diets are typically lower in iodine. 

Learn more about the link between iodine and thyroid health in this blog post. 

3. All gluten-free diets are created equal

Among functional nutrition practitioners, a gluten-free diet is one of the most recommended diets for Hashimoto’s and hypothyroidism. This is because gluten increases intestinal hyperpermeability even in healthy people: a risk factor for autoimmune diseases such as Hashimoto’s thyroiditis. Thus healing intestinal permeability is an important step in supporting symptoms. 

However, because gluten — a protein in wheat, rye, and barley — is structurally similar to our thyroid tissue, ingesting even the tiniest amount can trigger molecular mimicry. When this happens, the immune system can mistakenly attack the thyroid gland. For this reason, even those with non-autoimmune thyroid diseases (such as hypothyroidism or hyperthyroidism) are often advised to avoid gluten, at least temporarily. 

Reality: “Gluten-free” doesn’t necessarily mean “healthy”

While adopting a gluten-free diet is an important first step in supporting hypothyroidism, Hashimoto’s, and leaky gut, where many people go wrong is simply replacing gluten-containing foods with ultra-processed gluten-free alternatives. These foods are convenient, but many gluten-free alternatives to bread, pasta, crackers, flour, tortillas, and so on are ultra-processed — meaning they contain five or more ingredients and little to no nutrition.  

Ultra-processed foods aren’t just associated with cognitive decline, stroke, renal function decline, diabetes, obesity, cardiovascular disease, depression, and numerous other diseases. These foods are also associated with an increased risk of subclinical hyperthyroidism, leaky gut, chronic inflammation, and oxidative stress. Oxidative stress triggers systemic inflammation, which in turn can trigger Hashimoto’s and other autoimmune conditions. Over time, Hashimoto’s can lead to hypothyroidism as well. 

Instead of replacing gluten-containing foods with gluten-free alternatives, it’s best to follow a nutritious whole-food diet. The best foods to eat for hypothyroidism include fresh fruits and vegetables, gluten-free whole grains, nuts, seeds, healthy fats, and unprocessed meats. The core or modified autoimmune paleo diet (AIP) is one I commonly recommend in my nutrition practice. 

Nutritional therapy can help

The internet is filled with misinformation about health and nutrition, making it harder than ever to know which foods to avoid with hypothyroidism and which foods to eat for improved thyroid function. There’s usually some truth to this misinformation, but it takes someone knowledgeable in the field of nutrition to distinguish facts from fiction. 

This is why it’s so important to work with a registered Nutritional Therapy Practitioner. Book your free 20-minute inquiry call and take your first step toward regaining control of your health!