Foods can be a trigger with autoimmune thyroid conditions such as Graves’ Disease and Hashimoto’s Thyroiditis. As a result, I have most of my patients follow an elimination diet  initially. On the other hand, some healthcare professionals have all of their patients do food sensitivity testing to see what specific foods they are reacting to. While there are benefits to both of these methods, there are also limitations to both an elimination diet and food sensitivity testing, and in this post I’ll discuss the pros and cons of each of these so that you can better make an informed decision.
Before comparing the elimination diet with food sensitivity testing I’d like to discuss how food can cause autoimmunity in the first place. First of all, certain foods such as gluten can lead to autoimmunity by causing an increase in proinflammatory cytokines  and a decrease in regulatory T cells (1)  (2)  (3) . Molecular mimicry can also play a role, as what happens is that frequent exposure to certain food allergens can result in a decrease of oral tolerance . This in turn triggers an immune system response against various components of food proteins, and cross-reaction with B-cell molecules may trigger autoimmunity (3) . In other words, eating certain foods will result in the immune system attacking the food proteins, and in the case of mistaken identity the immune system can also attack bodily tissues with a similar amino acid sequence.
In addition to causing an increase in proinflammatory cytokines or resulting in a molecular mimicry mechanism, certain food allergens can also cause an increase in intestinal permeability, which is also known as a leaky gut . According to the triad of autoimmunity, a leaky gut is one of three factors required for the development of an autoimmune condition. The other two components are a genetic predisposition and exposure to an environmental trigger. Keep in mind that not all foods will cause a leaky gut, and what can make it challenging is that a leaky gut can actually cause the development of food sensitivities through a loss of oral tolerance.
What Are The Most Common Allergens?
While it is possible to have a sensitivity to any food, the following are considered to be the most common allergens:
In addition, these foods are also commonly problematic in some people:
The Elimination Diet vs. The Autoimmune Paleo Diet
Most people reading this are familiar with the autoimmune Paleo diet. This is similar to a standard Paleo diet, but also has people avoid eggs, the nightshades , as well as nuts and seeds. The reason why these and other foods such as grains and legumes are excluded is because they can interfere with healing of the gut. However, the autoimmune Paleo diet  also serves as an elimination diet, as you would essentially be eliminating the most common allergens, although some healthcare professionals do allow their patients to eat shellfish. The reason for this is because while shellfish is considered to be a common allergen, shellfish is AIP-friendly.
What Are The Benefits of An Elimination Diet?
There are a few reasons why I like to have my patients follow an elimination diet initially. First of all, I find that many patients can identify their food triggers if they do this type of diet carefully. Essentially you want to follow a strict AIP diet for a minimum of 30 days, and then after 30 days you would reintroduce certain foods one at a time, every three days, and pay close attention to symptoms. I have written a blog post on reintroducing foods  that I would recommend checking out.
Another benefit of the elimination/reintroduction diet is that it is more cost effective than doing food sensitivity testing. Testing for food allergens can be expensive, which would be fine if the information provided was completely accurate, or close to it. But food sensitivity testing is far from perfect.
What Are The Flaws of An Elimination Diet?
Although I start most of my patients on an elimination diet, this admittedly does have certain limitations. First of all, while many people are able to identify foods they are sensitive to, this isn’t always the case. For example, someone who follows an elimination diet and reintroduces a certain food might experience some obvious symptoms, such as bloating and gas, headaches, an increase in fatigue, brain fog , or other symptoms. On the other hand, some people don’t experience any overt symptoms upon reintroducing foods, and the lack of symptoms doesn’t always rule out a food sensitivity.
I will add that most people will notice symptoms upon reintroducing foods they are sensitive to if they pay close attention. Many times people are only focusing on digestive symptoms, but as I discussed above, other symptoms can develop as well. But how do you know if a specific symptom is related to the food you introduced?
For example, if someone reintroduces eggs, and they experience headaches, how do they know if the headaches were caused by the eggs? Perhaps it was a coincidence and the person might have experienced the headache regardless. This admittedly can be challenging, but in a situation where you are unsure if the symptom experienced was a result of the food that was reintroduced, what you would want to do is take a break from that food for a few additional weeks, and then you can try reintroducing the food again. If you experience the same symptom then you can almost be certain that the food is responsible for that specific symptom.
Another limitation of an elimination/reintroduction diet is that it is possible for someone to be sensitive to one or more of the “allowed” foods. For example, someone can be sensitive to AIP-friendly foods such as broccoli , avocados, chicken, raspberries, and other foods that are not part of an elimination diet. This admittedly is a major limitation of this diet, although I find that most of my patients don’t react to AIP-friendly foods.
What Does Food Sensitivity Testing Involve?
In the past I wrote an article entitled “Food Allergies, Food Sensitivities, and Thyroid Health ”. In this article I discussed the difference between a food allergy, a food sensitivity, and a food intolerance. As I mentioned in the article, a food allergy usually involves an immediate reaction to a food, and is considered to be IgE-mediated. This is the type of testing that most conventional allergists will conduct.
Food sensitivity testing usually involves a delayed reaction. As a result, it frequently will take a few hours, and sometimes a few days before someone will have a negative reaction to a food. While most food sensitivity panels involve Immunoglobulin G (IgG), there are other types of panels, including leukocyte activation testing (i.e. the ALCAT) and mediator release testing (MRT).
A food intolerance is usually the result of an enzymatic defect, and a good example of this is a lactose intolerance. Having a histamine  intolerance can be due to a defect in the enzyme DAO, although there can be other causes of this type of intolerance as well.
What Are The Benefits of Food Sensitivity Testing?
One of the main benefits of food sensitivity testing is that it has the potential to identify specific foods that you are reacting to. And while I can’t say that I’m a big fan of such testing due to some of the limitations I’ll discuss shortly, I have had some patients successfully identify foods that were causing problems. And in some of these cases the foods were allowed on an elimination/AIP diet.
Another potential benefit is that it might prevent the person from having to eliminate certain foods, although this is controversial. For example, if someone is eating gluten or dairy on a regular basis and tests negative for both of these, does this mean it’s safe to eat these foods, even though they are excluded from an autoimmune Paleo diet, as well as many other diets? Well, we need to keep in mind that false negatives are possible with this type of testing. I personally recommend for my patients to avoid gluten and dairy while restoring their health, regardless of what a food sensitivity panel shows. And with regards to some of the other “excluded” foods, we need to keep in mind that some foods aren’t excluded because they are common allergens, but instead are excluded because they have compounds which can affect the healing of the gut.
So for example, nightshades are excluded from an autoimmune Paleo diet due to the compounds which can potentially cause inflammation and/or an increase in intestinal permeability. Solanine is one example, as it’s a glycoalkaloid found in the nightshade foods, especially eggplant and potatoes, although it’s also found in tomatoes and peppers. But if someone tests negative for eggplant, white potatoes, tomatoes, and peppers on a food sensitivity panel, this doesn’t mean that these foods won’t cause problems.
Getting back to the potential benefits of food sensitivity testing, one additional benefit that comes to mind is that if someone tests positive, and if it is a “true” positive, then this serves as a baseline. In other words, if someone tests positive for one or more foods, and if they decide to reintroduce the food in the future when their gut is healed, they can do another food sensitivity test after reintroducing the food to see if they are still reacting to that specific food.
What Are The Disadvantages of Food Sensitivity Testing?
While it might sound great to do food sensitivity testing to determine the specific foods you are reacting to, there are a few disadvantages to this type of testing. Here are some of the main ones:
- False results are possible
- You need to either be currently eating the foods, or have recently eaten the foods you’re testing for to get an accurate result
- Doing this type of testing can be expensive
- Most food sensitivity panels are incomplete, meaning that they don’t test for all of the foods a person eats
- There can be differences between cooked and raw foods, yet most food sensitivity panels don’t test for both of these
What Approach Do I Take In My Practice?
As I mentioned earlier, I have most of my patients with Graves’ Disease and Hashimoto’s Thyroiditis follow an elimination diet initially in the form of the autoimmune Paleo diet. I have them do this for the first month, and if they are doing well I’ll encourage them to follow this diet for a longer period of time. But eventually I’ll have them reintroduce some of the excluded foods, as the goal isn’t to keep them on this diet on a permanent basis. However, there are times when I will order an IgG food sensitivity panel. First of all, if someone insists on ordering this type of testing then I’m fine ordering it.
Another situation when I might order such testing is if the patient started out with an elimination diet, and followed my other recommendations, but a few months later they still aren’t progressing. Another scenario where I might order a food sensitivity panel is if the patient is progressing but then they hit a roadblock and don’t show further improvement. So there are times when I will order food sensitivity testing, but it’s not a test that I recommend to all of my patients.
How Should YOU Detect Food Allergens?
After reading this you still might not be sure what approach you should take. Of course ultimately the decision is up to you, and if you are working with a natural healthcare professional then you might leave the decision making up to them. Some healthcare professionals recommend food sensitivity testing to all of their patients. On the other hand, others never recommend food sensitivity testing to their patients. I also should mention that some healthcare professionals use something called applied kinesiology to detect food sensitivities, which is a type of manual muscle testing.
What I recommend is to do some of your own research, and then find a doctor who is compatible with what you’re looking for. For example, if you decide that you don’t want to do food sensitivity testing, then it’s probably not a good idea to work with a healthcare professional who recommends food sensitivity testing for every patient. And if you want to get a food sensitivity panel done, then it doesn’t make sense to work with someone who is unwilling to order one for you.
In summary, foods can be a trigger of Graves’ Disease and Hashimoto’s Thyroiditis. And while I commonly have my patients follow an elimination diet initially, many natural healthcare professionals will have all of their patients do food sensitivity testing. There are pros and cons with both an elimination diet and food sensitivity testing. With regards to the different tests for food allergens, IgE testing is specific for food allergies, while IgG testing is for delayed food sensitivities. Leukocyte activation and mediator release testing are two other options, although there isn’t a lot of research on these two methods.