What is Hashimoto’s?

Hashimoto's disease - also known as Hashimoto's thyroiditis - is an autoimmune condition that affects your thyroid gland. Named after the physician who first described it in 1912, this condition occurs when your body's immune system mistakenly attacks your thyroid, impairing its ability to produce adequate thyroid hormones, leading to an underactive thyroid or hypothyroidism. As a result, people with Hashimoto's may experience symptoms such as fatigue, weight gain, depression, constipation, hair loss, and sensitivity to cold.

Conventional treatment often focuses on medications that only work to manage symptoms and have a long list of uncomfortable side effects. Instead, functional medicine aims to heal the root cause of Hashimoto's by addressing underlying triggers of your condition such as stress, environmental factors, and diet.

Foods to avoid with Hashimoto’s

Because Hashimoto’s is an autoimmune disease with inflammation at its core, a lot of the foods that should be avoided with Hashimoto's have to do with lowering the body’s inflammatory response. Studies have even found that the Autoimmune Protocol (AIP) Diet that eliminates most of the foods on this list can significantly improve (2) markers of inflammation in those with Hashimoto’s. With that said, these are the foods I see most often cause problems in people with Hashimoto’s and what I recommend eliminating first. 

1. Gluten

There are many people who can benefit from going gluten-free, but if you have Hashimoto’s it can be one of the biggest things you can do to alleviate your symptoms. In fact, a 2023 study published in Frontiers in Endocrinology (3) found that eliminating gluten had a positive effect on inflammation and thyroid function. 

This likely has to do with the fact that your immune system can oftentimes tag gluten as a “foreign invader” with antibodies for destruction. This can cause a lot of damage as your thyroid can be the one to get caught in the crosshair and get mistaken for gluten, due to a similarity in how the molecules look to your immune system.

2. Soy

Not only is soy also a cross-reactive to gluten, it also contains phytoestrogen compounds known as goitrogens that have been shown (4) to inhibit thyroid hormone synthesis by inhibiting your body’s intake of iodine - a necessary nutrient involved in the makeup of your thyroid hormones.

3. Dairy

If you have Hashimoto’s dairy products can cause inflammatory reactions for a variety of reasons, including:

• Lactose: If you are lactose intolerant you may lack the enzyme responsible for helping you digest dairy.
• Casein: This milk protein can cause a similar inflammatory reaction as gluten. If you have leaky gut syndrome, prolonged dairy exposure could result in symptoms of digestive distress and autoimmune-inflammatory symptoms like rashes or joint pain.
• Additives: Conventional dairy is pumped full of hormones and antibiotics that could potentially have a negative impact on your health and inflammation levels.

If you can handle lactose and casein but are still having problems with dairy, you may just have a problem with conventional dairy and need to make the switch to small amounts of grass-fed dairy products.

4. Cruciferous vegetables

Although filled with other nutrients vital for healthy thyroid function, vegetables like broccoli, Brussels sprouts, cabbage, and kale also contain goitrogens that, when consumed in large amounts, might interfere with thyroid function. However, it’s important to note that cooking these vegetables can help deactivate the goitrogenic compounds. 

Since these vegetables are rich in other nutrients, it’s important to work with your doctor to determine if your specific health case requires eliminating them altogether or if you just have to eat them in moderation.

5. Nightshades

Nightshade vegetables and fruits like tomatoes, potatoes, eggplants, and peppers contain alkaloids compounds that can be extremely inflammatory for those with autoimmune conditions. Although more research needs to be done on nightshades and Hashimoto’s specifically, studies have found evidence that nightshades can be a potential trigger for other autoimmune conditions like Inflammatory Bowel Disease (5) and Rheumatoid arthritis. (6)