Food Sensitivities and Hashimoto's - Dr. Izabella Wentz (2023)

I first set out to discover lifestyle interventions to help me heal from Hashimoto’s shortly after being diagnosed. My doctor prescribed me thyroid medication. He told me I would be taking it for the rest of my life, and that was the end of the story.

Intuitively, I knew there had to be a better way, so I sought out a functional medicine practitioner who prescribed food sensitivity testing for me. After three days of avoiding the reactive foods that showed up on my test (gluten and dairy being my top triggers), my acid reflux, bloating, irritable bowel syndrome, and lifelong stomach pains went away. The pain in my arms went away a few weeks after. Uncovering my food sensitivities was my first step into the world of natural health and healing, and has changed the course of my life and career.

Since Hashimoto’s and food sensitivities often co-occur, and each can exacerbate the other, addressing food sensitivities can be key to reducing thyroid symptoms.

In fact, I would go so far as to say that identifying and eliminating triggering foods can be one of the most powerful interventions for people with Hashimoto’s.

In this article, I’d like to explore:

• The most common food sensitivities for those with Hashimoto’s
• How to test for food sensitivities
• Tips for maintaining a specialized diet
• How to incorporate foods back into your diet

How are Food Sensitivities and Allergies Different?

Though the terminology often gets confused, food sensitivities are different from food allergies.

Food allergies are generated by the IgE branch of the immune system, and reactions will usually show up within minutes of ingesting the reactive food. Reactions can include an itchy rash, throat or tongue swelling, shortness of breath, vomiting, lightheadedness, and low blood pressure, and can often be life-threatening. Shellfish and nuts are the most common foods that result in an IgE food allergy.

Food sensitivities, on the other hand, are governed by different branches of the immune system: the IgA, IgM, and IgG branches. Interestingly, the IgG branch is also thought to be responsible for creating thyroid antibodies in many cases of Hashimoto’s.

From my experience with clients, I’ve seen that eating foods that stimulate the release of IgG antibodies promotes the production of thyroid antibodies, thus furthering the attack on the thyroid.

These reactions may take a few hours or even a few days to manifest. Here are some of the most common symptoms of food sensitivities:

• Acid reflux
• Bloating
• Irritable bowel syndrome
• Heart palpitations
• Joint pain
• Anxiety
• Tingling
• Headaches
• Skin breakouts

Food sensitivities generally occur when we eat the same foods over and over, in the presence of intestinal permeability (leaky gut). Leaky gut can be ongoing or acute, and can be caused by stress, toxins, triggering foods, and infections.

When our gut is compromised — for instance, when we’re under stress, or when we have an infection like H. pylori — the body is more likely to recognize certain proteins as foreign and make antibodies, thus resulting in the development of new food sensitivities.

The good news is that, unlike true allergies, most IgG reactions can be reversed by removing the triggering foods for three to six months, then rotating them in your diet, and eating them in moderation. The idea here is to reduce the inflammation in the gut and give it a chance to heal; once that is resolved, food sensitivities may resolve as well.

The Most Common Offenders

The most common food sensitivities found in people with Hashimoto’s are gluten, dairy, soy, grains (corn, in particular), nuts, seeds, and nightshades (eggplants, potatoes, tomatoes, and peppers). Caffeine and alcohol also tend to be problematic.

Some people have a nightshade sensitivity because nightshades contain components called “saponins” and “lectins,” both of which have been linked to digestive problems and even intestinal damage. Undigested lectins can cause an immune response, which might be why some people are triggered by nightshades.

I am grateful that I never had to avoid nightshades in the early stages of my healing journey, and I believe this is because I only ate organic heirloom tomatoes from my mom’s garden during the summer. I think that skipping the pesticides and GMOs, as well as only eating them seasonally, may have helped me to avoid this type of sensitivity. However, I know many people are sensitive to nightshades and feel better without them in their diet.

In surveying my readers and clients, I’ve found that about 93 percent have felt better on a gluten-free diet. Another 75 percent reported feeling better on a dairy-free diet, 73 percent felt better off grains, and another 60 percent said they felt better soy free. Egg- and nightshade-free diets were helpful 40 and 35 percent of the time, respectively.

Gluten

Gluten is a protein found in barley, rye, and wheat. It’s a staple in the Western diet that’s found in most breads, cereals, and pastas, but can also be hidden in many other food products.

There are three different reactions a person could have to gluten-based foods:

1. The celiac reaction is the most severe form of gluten response. If those with celiac disease do not stay on a strict gluten-free diet, they face significant, life-affecting symptoms, including serious intestinal damage.
2. The allergic reaction is governed by the IgE branch of the immune system and results in immediate reactions like anaphylaxis, difficulty breathing, rashes, and hives.
3. The Type IV delayed hypersensitivity reaction is governed by the IgG branch of the immune system. Interestingly, Hashimoto’s is also a Type IV delayed hypersensitivity reaction.

Reactions to gluten, many of which are also considered typical hypothyroid symptoms, include bloating, irritable bowel syndrome, acid reflux, stomach pains, brain fog, fatigue, hair loss, weight gain, cold intolerance, anxiety, palpitations, joint pain, carpal tunnel, allergies, and panic attacks.

Not long after having been diagnosed with Hashimoto’s, I had been tested for celiac disease as well as IgE food reactions, but both of those tests were negative. I decided to try IgG food sensitivity testing, and the tests revealed that I had IgG reactions to gluten, as well as to dairy proteins (whey and casein). (More on dairy further on in this article!)

Non-Celiac Gluten Sensitivity (NCGS)

Research suggests that many people with Hashimoto’s are prone to some degree of gluten sensitivity — but this doesn’t necessarily mean that they have celiac disease.

Soon after learning of my gluten and dairy sensitivities, I came across a condition known as non-celiac gluten sensitivity (NCGS). People with NCGS have celiac-like reactions to gluten, yet they don’t test positive to the typical IgA celiac antibodies — nor do they experience the characteristic damage to intestinal cells that is seen in celiac disease.

While there is some research supporting that NCGS does exist, some conventional doctors and even the media may still view it as controversial. The challenge, in my opinion, is that there is no single diagnostic test for, or cause of, non-celiac gluten sensitivity.

Another thing to note about NCGS is that wheat-based foods contain FODMAPS (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols), a collection of short-chain carbohydrates that aren’t absorbed properly in the intestines of those with IBS and certain intestinal disorders like small intestinal bacterial overgrowth (SIBO). In a recent study, researchers have concluded that fructan, a type of oligosaccharide that is found in wheat, is to blame for NCGS symptoms, and not gluten. (I personally believe this could be the case for some, but not all people with NCGS.)

Histamine intolerance (which many people with Hashimoto’s can also have) has also been tied to NCGS, as have other reactions to other substances such as nickel.

I personally believe that NCGS is still an emerging concept that should be considered an umbrella term for the various reasons why a person may react to gluten-containing foods. I also always encourage you to listen to your own body (and not necessarily conventional media headlines) if you believe you have a sensitivity to certain foods.

My personal and clinical experience has shown that gluten sensitivity is one of the most significant triggers in Hashimoto’s, and most people experience significant health improvements when they remove gluten from their diets. In fact, removing gluten can help reverse intestinal permeability (which is always a precursor to autoimmune disease), as well as reduce one’s thyroid antibody levels!

You can read more about the benefits of a gluten-free diet for Hashimoto’s here.

Dairy

People with Hashimoto’s are more likely than others to have sensitivities to the proteins found in dairy: casein and whey.

Although lactose intolerance and dairy protein sensitivity can cause similar symptoms (like bloating and diarrhea), they are not the same thing. Lactose intolerance involves a lack of enzymes that prevents the proper breakdown of the milk sugar lactose, and may be managed via enzyme-containing pills like Lactaid. Additionally, lactose intolerance will not cause intestinal tissue inflammation or damage.

Dairy sensitivity is more like gluten sensitivity, where both are mediated by the IgG branch of the immune system. It is a Type IV delayed hypersensitivity reaction. Hashimoto’s is also considered a Type IV delayed hypersensitivity, and experience shows that eating foods that stimulate the release of IgG antibodies and promote a Type IV delayed hypersensitivity response, will also result in an increase in thyroid antibodies.

The most common ways people react to dairy include gut reactions (bloating, diarrhea, and acid reflux), lung reactions (coughing, asthma, sinusitis, postnasal drip, and mucus), and skin reactions (eczema, rashes, or acne).

So why is dairy a common food sensitivity? Cow’s milk contains proteins that are different from the proteins found in human milk. With intestinal permeability, the body is likely to recognize these proteins as foreign invaders and make antibodies to the proteins.

Many people believe that non-cow milk options may be safer. However, goat’s milk and sheep’s milk proteins are very similar to cow’s milk proteins and have about a 60-75 percent cross-reactivity rate, meaning that 60-75 percent of people who are sensitive to cow’s milk casein will also react to goat and sheep’s milk casein.

Once a person becomes sensitized to the casein protein, they will react to all forms of dairy, with the possible exception of camel milk. Camel milk does not contain whey protein and has a different structure of casein — the two most reactive parts in cow’s milk. Camel milk also has little fat (the lactose content is only 4.8 percent), making it easily tolerated by most people with lactose intolerance.

For me, dairy was a greater reactive food than gluten. Eating even tiny amounts of dairy resulted in coughing, bloating, acid reflux, joint pains, and diarrhea. I’ve been dairy free for years now, and my food reactions are all but gone. However, a small amount of dairy will still trigger a cough for me.

If you think dairy may be a problem for you, I recommend removing it from your diet for at least two to three weeks and noting which symptoms are relieved for you.

Soy

The third most common food that those with Hashimoto’s may be sensitive to is soy. Many gluten-free products contain soy, which can be problematic for thyroid patients. It can block the activity of the TPO enzyme and worsen the autoimmune attack on the thyroid. It would seem that my own thyroid condition became worse after eating soy-containing gluten-free products. After only one month of giving up all soy, however, my thyroid antibodies dropped from 800 IU/mL to 380 IU/mL!

A soy sensitivity will often present as gut symptoms such as abdominal pain, loose stools, nausea, or vomiting, while a significant number of people will also experience mental symptoms such as headaches, dizziness, brain fog, anxiety, depression, fatigue, and insomnia.

Soy can be hard to avoid, as it’s not only found in foods such as edamame beans, soy milk, tofu, tempeh, miso, and soy sauce, but also in many processed foods and even supplements. Ingredients to look out for include soy lecithin, bean curd, hydrolyzed soy protein, soybeans, edamame, natto, okara, yuba, tamari, Olean, gum arabic, carob, and hydrolyzed vegetable protein.

Food Sensitivity Testing

When we eat the foods that our body is sensitive to, on a daily basis, it is very difficult to connect the foods with the symptoms we are having. For example, people who continue to drink milk multiple times a day might be tired, have joint pain, and feel bloated on a daily basis, but won’t be able to pinpoint these symptoms as linked to a possible dairy sensitivity.

This is because every time we eat a problematic food, the body becomes depleted in its ability to protect itself, and the reactions become more chronic, making it more difficult to identify food sensitivities.

That is why I believe testing is so important.

There are a multitude of different food sensitivity tests out there, and none of them are perfect. Some will present with false positives; others, false negatives. You may have to try more than one approach to uncover all of the foods that are causing your symptoms, but there are two types of tests that I recommend most often.

Elimination Diet

The best place to start when trying to identify your own particular food sensitivities is with an elimination diet. The first step will be to remove gluten, dairy, soy, and other foods that you suspect you may be reactive to. These may include fruits and vegetables you’ve been eating all the time. Avoid these foods completely for at least two weeks. During this time, track which of your symptoms have improved versus which still remain.

After you have spent a period of weeks without the suspected food irritants, try slowly adding them back in one at a time, waiting several days between each food to notice if any of your symptoms return. Many people will notice an immediate reaction when they reintroduce a food they are sensitive to. If you experience this, take this as a very strong clue that you should avoid that food! (Read more about how to do an elimination diet here.)

If, after removing gluten, dairy, soy and other foods you suspected were problematic, you are still experiencing symptoms of food reactivity, it might be time to dig a little deeper.

Test Kits

Some food sensitivities can be harder than others to pinpoint, and some people may need to see the numbers on paper before they are able to accept that they will need to give up a food they love in order to feel better. In those cases, I recommend food sensitivity testing through a lab. While most conventional medical professionals and insurance companies consider food sensitivity tests to be “experimental”, I can testify that as I “experimented” with removing the foods the tests found to be reactive for me, I felt dramatically better!

The test that I found to be highly accurate for myself and my clients is the Alletess Lab food sensitivity test. If a certain type of food comes up positive on that test, you’ll know that you are sensitive to it and need to eliminate it from your diet in order to feel better.

Alletess Lab works primarily through integrative and functional medicine physicians, so if you have one, you can speak to them about ordering the test for you.

MyMedLab also offers Alletess food sensitivity testing for self-order, without a doctor’s prescription. The test kit comes with a blood spot collection paper, and can be mailed to just about anywhere in the world. MyMedLab offers two options to test for the most commonly eaten foods: the 184 Food Panel and the 96 Food Panel.

I began with the 96 Food Panel and found that it was enough to uncover most of my food triggers. I now repeat the 184 food Panel on an annual basis to be sure that I’m staying on top of potential triggers, as our sensitivities and reactions to foods can change with time.

How Do I Eat This Way?

While it can be quite liberating to figure out which foods are problematic for you, and eliminating them can make you feel so much better than you have in years, you may find yourself asking, “How can I continue to eat this way, especially when the foods I am so sensitive to are so prevalent in our modern diets?”

While it can be quite challenging to adapt one’s whole way of eating, I have found many tips and tricks to modifying my diet for Hashimoto’s that make me feel great, and make the sacrifices feel easy and doable.

Cook Your Meals at Home

When you’re avoiding certain foods, particularly foods like wheat and dairy that are so prevalent in our culture, the best strategy is to cook most of your meals at home — at least until you’ve mastered your diet and know where you can order specially prepared meals with safe ingredients in your area, it’s best to avoid eating out as much as possible.

If you feel like you may be missing out on social gatherings, try hosting a family dinner at home and incorporate some delicious new recipes. That way, you can control what food you are eating while still enjoying time with friends and family. If you’re heading to a gathering at someone else’s home or at a restaurant, try eating beforehand, or pack a bagged lunch and explain that you are on a special diet for a time. Most people will understand and be gracious about your health needs.

The good news is that there are so many delicious recipes that can inspire you to create some delicious home-cooked meals, while still avoiding the foods that cause reactions for you. You can order my new cookbook, Hashimoto’s Food Pharmacology: Nutrition Protocols and Healing Recipes to Take Charge of Your Thyroid Health, which contains some of my own favorite recipes that are Hashimoto’s-friendly and are free of common food sensitivities.

If you really don’t have time to cook, or just don’t like spending a lot of time in the kitchen, there are even some Paleo-friendly food services that allow you to customize your meal plans to your own food sensitivities. Paleo On the Go offers regular Paleo, ketogenic, and Autoimmune Paleo options, while Trifecta offers customizable Paleo and vegan options.

Adopt a Paleo-Style Diet

Though being on a Paleo diet isn’t required for healing from Hashimoto’s, and everyone’s diet is going to look a little bit different to suit their individual needs, I have found a Paleo-style diet to be helpful to a lot of people with thyroid issues. First, the Paleo diet eliminates the most common food sensitivities in Hashimoto’s: gluten, soy, and oftentimes, dairy. Second, it places an emphasis on quality protein, fruits, and vegetables — all of which are healing foods.

There are so many resources to be found on eating a Paleo-style diet, which makes it easy to incorporate into your daily life. For more information on what eating Paleo looks like, you can take a look at this article on Paleo diets and Hashimoto’s, or this article that dives deeper into the Autoimmune Paleo diet.

Use Whole Foods to Help You Heal

It can be easy to focus on the foods that you have to give up when you uncover your food sensitivities. I know firsthand how hard it can be to give up some of your favorite foods. But, I’ve found it helps to place your focus on adding in nourishing foods that help your body to heal. When the food you are eating makes you feel great, it is much easier to give up the foods that made you feel so terrible!

Some of the foods I always recommend for people with Hashimoto’s include green smoothies, bone broth, grass-fed meats, fermented foods, gelatin, hot lemon water, beets, cruciferous vegetables, cilantro, fiber, green juices, berries, and turmeric. All of these foods have amazing healing qualities, and when you feel better, you will be encouraged to keep eating in a way that nurtures your body and keeps Hashimoto’s symptoms at bay.

For more information about food and diet, check out my article on the best diet for Hashimoto’s.

Will I Ever Be Able to Eat My Favorite Foods Again?

The concern that most people have when they start to eliminate foods from their diet is that they will never again be able to enjoy the foods that they love. Some of us will even avoid doing any type of food sensitivity testing because we’d rather be ignorant to the news that we can no longer eat our beloved grilled cheese sandwiches and ice cream cones!

I’ve been there. I ate a whey protein/yogurt shake for breakfast, tuna melt bagels for lunch, and loved snacking on crackers, bread, cookies, donuts, and cottage cheese at every chance I got. I was an avid baker and always attacked the bread basket at restaurants. I loved fruit but was not a big fan of meat or vegetables, so I knew I was going to miss these foods. It took seeing my test results in black and white to make the change, and all of a sudden, something shifted in me. I went out to an all-you-can-eat big Polish buffet with pierogi (made from dough and farmer’s cheese), kopytka (dumplings), kotlety (breaded pork tenderloins), and a smorgasbord of cookies and cakes… and said my goodbyes to the foods I had grown up with.

The good news is that, after a period of elimination and gut healing, there are many foods that you will be able to add back into your diet. Depending on how many foods you are sensitive to and how damaged your gut is when you begin eliminating foods, the amount of time you’ll need to wait before reintroducing those foods will vary. Everyone starts from a different place, and your own timeline may be different than the next person’s.

The turning point for me was when I began to incorporate nutrients, digestive enzymes, and more healing foods like bone broth, green juices, and green smoothies into my diet. I began to feel and look better, and began to tolerate more foods. Continuing to nourish my body, while treating gut infections and toxins, allowed me to eventually incorporate more and more foods back into my diet, and I’ve now been able to reintroduce most foods I was once sensitive to!

Before reintroducing foods to your diet, I suggest eliminating that food completely for a period of three to six months. One study from the Journal of Laboratory and Clinical Medicine looked at the half-lives of IgG antibodies in patients with immunodeficiencies and found that the total half-life of IgG antibodies was 25.8 days. A half-life refers to the amount of time required for a substance to be reduced to one-half of its previous level. Therefore, we can infer that it will take a period of several months for the antibodies to be fully eliminated from your body.

You will also want to make sure that your gut is healed by incorporating nourishing foods and addressing any gut infections that you may have. When you feel that your symptoms have abated, and you are ready to reintroduce some previously reactive foods, be sure to go slowly, introducing one food at a time to see how you feel.

Will I Ever Be Able to Eat Gluten or Dairy Again?

Though my body has healed to the point where I can tolerate all other foods I had previously eliminated, I still follow a gluten- and dairy-free diet.

In general, I believe that most people with Hashimoto’s should stay on a gluten-free diet. Though there are some people that seem to be able to add gluten back into their diets without incident, the majority of people will experience adverse reactions and seem to fare better on a gluten-free diet.

Similarly, dairy seems to be problematic for most people with Hashimoto’s, and I generally recommend that they continue to eliminate all dairy products from their diets. If you feel you’ve healed to a point where your gut can handle it, you can try adding in a small amount of dairy and note how you feel.

Again, each person is different and there is no “one-size-fits-all” diet that will heal everyone. You will need to experiment with what foods do and don’t work for you, and tailor your own diet to a way of eating that makes you feel great.

Next Steps

When my clients hear this information about food sensitivities, some are excited because they finally have a starting point from which to approach feeling better. Others feel overwhelmed, especially if they are dealing with debilitating fatigue, and wonder how they’re going to find the energy to incorporate a new diet into their lives.

I’m here to tell you that the changes you make to your diet become easy to manage with a little time and practice, and the relief of symptoms you may experience will be more than worth it!

If you are feeling overwhelmed, I encourage you to take it slow. Try removing one food at a time and give yourself time to adjust to the change. We are all different, with different sensitivities. What works for one person may not work for the next.

Stick with it and let your diet evolve with you — you are bound to find a way of eating that works for your lifestyle and makes you feel good!

To dig deeper into identifying food sensitivities and creating a diet that helps your body put Hashimoto’s into remission, I recommend picking up a copy of my book Hashimoto’s Protocol. In it, you’ll find clearly defined steps for uncovering and treating your own root causes.

If you’re looking for simple yet nutritious recipes that are thyroid-friendly, be sure to check out my new Hashimoto’s Food Pharmacology: Nutrition Protocols and Healing Recipes to Take Charge of Your Thyroid Health cookbook!

In this book, I give my readers a crash course on how to heal your body with nutrition, filled with recipes and eating strategies that can be easily incorporated into your daily life. All the recipes remove the most harmful trigger foods and incorporate beneficial foods to help your body heal and your thyroid thrive.

As always, I wish you the best on your healing journey!

P.S. You can also download a free Thyroid Diet Guide, 10 thyroid-friendly recipes, and the Nutrient Depletions and Digestion chapter of my first book for free, by signing up for my weekly newsletter. You will also receive occasional updates about new research, resources, giveaways, and helpful information.

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References

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Note: Originally published in May 2015, this article has been revised and updated for accuracy and thoroughness.