A little over five years ago, I stopped eating one food. About a month later, I suddenly realized that, for the first time in nearly seven years, I did not want to die. My history of untreatable suicidal depression, insomnia, and anxiety became just that: history. At the same time, a bunch of other little health problems cleared up (skin infections, weak fingernails, acne, etc.). I felt amazing!
It turns out I spent most of my life depressed and sick because I didn’t know I was allergic to wheat, which, as anyone with celiac disease can tell you, is omnipresent in the American food system. Over the next few years, I discovered more food allergies and sensitivities with symptoms ranging from “severe stomach pain” (guar gum) to “turn bright red and feel tired” (dairy). Eventually I learned that multiple food allergies was a common symptom of my rare genetic disease, hypermobile Ehlers-Danlos Syndrome (hEDS).
At first I thought my experience was a fluke, but now I’ve met dozens of other people who had similar major improvements in their health once they figured out their own food sensitivities. I am sharing how I found my food sensitivities in this post because, frankly, finding them is super hard! While most of my friends without hEDS have only one food sensitivity, we all struggled for years or decades to figure out the problem, only to have it disappear once we stopped eating the right foods.
Some of the reasons why finding food allergies is so hard:
- Most doctors are dismissive of the idea that health problems can be caused by food sensitivities or allergies and will assure patients that their problem “can’t” be caused by diet.
- Food allergies can be erroneously ruled out by inaccurate tests. For example, food allergy blood tests can only detect a subset of allergies, but are often taken as proof of no allergy.
- Allergy tests can also have false positives if people are experiencing a lot of allergic reactions at once.
- Some allergies are the result of a combination of different factors. For example, in oral allergy syndrome, people have allergic reactions to specific foods only when certain pollens are in the air.
- The symptoms of a food sensitivity can be subtle. Many of us think all food allergies are life-threatening, like your friend with the nut allergy who has to carry an Epi-Pen everywhere. But if you have a milder allergy or sensitivity, the symptoms might be far subtler: maybe three or four small red dots on your chest that you mistake for pimples, or abdominal swelling that you dismiss as “just gas.”
- If you eat the thing you’re allergic to on most days, you might never realize the connection between the food and the symptom, or that it is even a symptom, because you have the symptom all the time and that’s just “how you are.” If your allergy is related to a genetic predisposition, other members of your family may also “just be that way.”
- If you have multiple food sensitivities, the symptoms of the other sensitivities might mask any relief you get from stopping eating just one of the foods.
- Most of us eat a lot of processed foods, which not only have dozens of ingredients, but also contain trace amounts of common food allergens that aren’t even listed on the label.
My experience finding my wheat allergy illustrates many of these points. I have an unusually good doctor who had suspected for years that I had a wheat allergy and repeatedly urged me to try eating gluten-free for a month. But the first time I tried going gluten-free, nothing changed because… I was still eating wheat. For example, I didn’t know that most oatmeal has wheat flour mixed in it. Turns out, oatmeal is often made in the same factory as wheat flour, and the wheat flour floating in the air gets into the oatmeal. Also, I’d tested negative for the common genetic markers for celiac so I “knew” that small amounts of wheat couldn’t hurt me (wrong!), so I continued to eat soy sauce even though I knew it had wheat in it. At the end of the month, I told my doctor I clearly didn’t have a gluten allergy because nothing had changed—when I had eaten wheat almost every day of that month.
I tried going gluten-free again years later after having several friends with celiac disease who showed me what it took to eat 100% gluten-free. I also spent a lot of time on gluten-free websites self-educating myself on the American food system. This time it worked; I felt somewhat better within two weeks, and obviously better after one month. The most striking change was that I no longer had suicidal ideation for the first time in seven years. Once my body was healed up enough, I could tell when I’d eaten wheat by the return of small, immediate symptoms. The effects of my wheat allergy are so bad that I’ve only voluntarily eaten wheat once in the five years since I went completely gluten-free for a month—but until then, I had no idea I was allergic to wheat.
Signs you might also have an undiagnosed food allergy:
- Skin problems (acne, blackheads, red spots, redness, scaly skin, oily skin, rashes, etc.)
- Gastrointestinal problems (acid reflux, gas, IBS, diarrhea, constipation, etc.)
- Joint pain
- Muscle pain
- Migraines or headaches
- Frequent colds and sinus infections
All of these symptoms can also be caused by other problems, but if you’ve been trying to treat the symptoms for years and having little success, it might be reasonable to experiment with just not eating some foods for a month. Talk to your doctor first, but so far I haven’t found any peer-reviewed research showing that, e.g., not eating wheat is harmful to the average person.
Some of these symptoms seem straightforwardly connected to food allergies (like anything involving the GI tract) but others are more mysterious. I have various theories about how all of these things are connected, supported to one degree or another by peer-reviewed medical research. Skin symptoms seem relatively straightforward: acne is hard to differentiate from hives, raised histamine levels clearly affect the skin, and skin pores are one method of excreting unwanted material from the body. On mental symptoms, my theory is that some food allergies harm the small intestines enough that your body has difficulty absorbing nutrients, like vitamins and fats, that are required for the healthy functioning of the brain. You may be eating a nutritious diet, but your body literally can’t digest what you eat. When it comes to asthma and colds, my theory is that the inflammation created by the food allergy makes the lining of the respiratory tract swollen and irritated, making it easier for germs to infect it. Also, food allergies can aggravate GERD, and the reflux can actually get into the lungs, causing asthma. These are my theories; all I know for sure is that for me and many other people I know, the symptoms listed above declined or disappeared when we eliminated certain foods from our diets.
So, how do you figure out if you have a food sensitivity? I’m going to describe three methods:
- Medical testing
- Eliminate one food at a time
- Eliminate all common allergens and reintroduce one-by-one
If your symptoms are severe and you’ve been trying to solve them for a long time, I’m going to recommend option 3 as the quickest route to feeling better.
Medical testing for food allergies is quite limited but if you have health insurance that covers these tests it can be an easy win. All food sensitivity tests I’ve researched have significant false negative rates (a false negative means the test says you don’t have a reaction to the food when in reality you do). Here are a few of the most common:
- Celiac testing: Celiac disease is “multifactorial”—a combination of several genes and environment. The genetic testing can only say whether you have a known genetic predisposition to develop celiac disease. The other celiac tests can show that you have active celiac disease, but many people who don’t test positive still feel much better when they don’t eat wheat.
- Skin test: This is a test where food extracts are applied to the skin (often in small cuts or pricks) and observed to see whether an allergic reaction in the skin results. This can find a food allergy, but not rule one out, as it is common for different tissues of the body to have different levels of allergic reaction to the same allergen. Your skin might not mind watermelon, but the inside of your throat might quite object.
- Blood antibody tests: There are many different kinds of antibodies involved in food allergies, and current tests only measure a small subset of the possible antibodies. They also only work for foods you are currently being exposed to.
Skin and blood tests are also limited to a particular subset of foods, and you have to choose which ones to test for. You may not order the right test, or the test might not be available through your health care system, or the test for the food you are allergic to might not exist. When medical tests do find a food allergy, you can confirm the allergy by avoiding that food completely and then eating it again and observing your body’s reactions.
If you are lucky, medical testing will find your food sensitivity quickly, and your food sensitivity journey will be over. For lots of people, it’s not that easy. For me, I found one of my food sensitivities through a blood test (mustard seed), but I tested negative for all of my other food allergies.
Eliminate one food at a time
Another approach is to pick a specific food and eliminate it entirely from your diet and see how you feel. Sometimes you’ll have a suspicion or bad feeling about the food that you’re allergic to, based on unconscious associations between eating a particular food and feeling worse afterward. Often we ignore this unconscious dislike because as a society we praise people for having broad palates and for not being “picky eaters.” You may think, hey, bell peppers aren’t my favorite food, but they aren’t disgusting and I’m an adult, so I’ll eat them whenever they are served to me—when actually you don’t like them because they make you feel mildly sick for several days after you eat them.
The difficulties with the one-food-at-a-time approach include:
- If you don’t find the food immediately, it may take years or decades to find it, since it takes several weeks to test each food.
- If you have multiple food allergies, your reaction to the foods you are still eating may hide the relief you get from stopping just one food.
- You may have a sensitivity to an entire class of foods, such as nightshades (tomatoes, potatoes, peppers, eggplant, etc.).
- Some foods are common contaminants of processed foods—that is, they aren’t on the ingredient label, but they are present in the food due to contamination when they are processed in the same facility or cooked in the same kitchen.
- Some foods are listed on the labels of processed foods but hidden under catch-all terms like “natural flavors” or “spices.”
While one-food-at-a-time technique eventually worked for my wheat allergy because it was so severe, it did not work the first time I tried it, due to contamination, and it did not work for my other allergies. For several years I had a rotating cast of foods I didn’t eat, on the theory that only one food was causing the problems: eggs, then dairy, then corn. I’d feel a little better than I did eating all foods, but I always assumed only one food was causing the problem, and as soon as I stopped eating a new food, I’d start eating the old food again, just because it is so hard to find something to eat otherwise.
One-food-at-a-time is a good choice when you have a list of a few top suspects for your food sensitivity and you have the time and resources to research how it might be hidden in your foods and make sure you’re truly eliminating it.
Eliminate all common allergens and reintroduce one-by-one
You can also try eliminating a big list of foods that often cause allergies and sensitivities all at once, waiting a month, and seeing if any of your symptoms improve. If they do, you then introduce the foods back one by one and see if your symptoms come back. This system has the advantages of feeling better quickly if the foods you are sensitive to are on the list, and then continuing to feel good except for the brief periods of time after you reintroduce those foods (as opposed to feeling bad until you find the food you are sensitive to, as in one-by-one elimination). It also works better when you have multiple food allergies, as the symptoms for one are less likely to mask the symptoms of the other if you eliminate them at the same time. The downside is that it’s really hard to eat for several months: you’ll have to relearn how to cook with a different and smaller set of ingredients and eating out will be really tough. Depending on how you currently eat and what grocery stores are near you, you may save a lot of money on food, or you may need to spend more money on food.
If you have really serious symptoms that are interfering with your life, or you have already tried eliminating one food at a time and felt a little better but not significantly better, this might be the right option for you. There are two well-documented diet plans you can try.
Autoimmune Paleo Diet
The word “paleo” probably reminds you of that annoying person lecturing other people about what to eat based on their personal fantasies about what people ate in prehistoric times. That’s super annoying and also not useful for tracking down food allergies. I’m talking about a different version of “paleo” here: the Autoimmune Paleo Diet is based on hundreds of peer-reviewed research papers on the effects of specific foods on modern-day humans. This version of “paleo” is about looking at the science and saying, “Hm, perhaps that food is harmful because we measured the way it harmed people in a scientific study.”
The Autoimmune Paleo diet (AIP diet) is the diet I tried when I was having mysterious stomach pain that prevented me from sleeping (that turned out to be guar gum). It is especially good for people whose symptoms are connected to autoimmune diseases, but it also works for many other common food allergies and sensitivities. In addition to eliminating possible harmful foods, it also recommends a lot of highly nutritious foods: bone broth, organ meats, high vitamin vegetables, etc. The goal is to give your body the nutrients it has been missing out on so it can rebuild your tissues. It also recommends sources of helpful bacteria to rebuild your gut flora. This diet comes with instructions on when and in what order to reintroduce foods.
The upside of this diet is that if you are suffering from any of dozens of problems, you’ll start feeling better pretty quickly. When I tried it, I went from being sleep-deprived due to stomach pain waking me up, to sleeping through the night in something like a week, which let me keep working my job when I thought I might have to take medical leave. You’ll also have a pretty clear idea of which foods were causing the problems if you follow the instructions on reintroducing foods.
The downside of this diet is that most people will have to relearn how to cook, buy new ingredients and cooking utensils, and have a lot of trouble eating at restaurants. If you share meals in a household, you will probably have to cook separate meals for yourself for a while (and maybe forever depending on what you learn). This diet involves eating a lot of animals; even if you are already comfortable doing that, it recommends eating parts of animals that many people in the U.S. think are gross. (This part isn’t necessarily crucial; for me, drinking high quality bone broth was the important part.)
I personally struggled a lot with the ethics of eating more animals. If I had my way, I would be vegan for environmental reasons, and eating animal products really grates on me. I came to this resolution for myself: I have a medical condition which requires me to eat a certain amount of animal products in order to be a healthy functioning member of society. Within those constraints, I make the most ethical choices possible. One aspect of this diet is that I often eat the parts of animals that end up being thrown away, such as bones. I also eat red meat very seldom, since it contributes to greenhouse warming more than pork or chicken or fish.
There is an extremely long and detailed book outlining all the research behind the AIP recommendations, but it takes forever to read and focuses on the theory more than the practice. I did the AIP diet using the Autoimmune Paleo Cookbook by Mickey Trescott, which has most of the information you would need to go through the entire process of finding your food sensitivities. I also did a couple of online consultations with Trescott to ask advice on tricky problems (e.g,. for a while I could eat while white rice no problem, but brown rice or rice flour made me sick). I also wrote a blog post about eating paleo while shopping (mostly) at Trader Joe’s.
Whole 30 with modifications
There is a lot of nonsense about “purification” and “detox” and “eating clean” around the Whole 30 program, and I object strongly to that kind of moralistic framing of food. If you can work around that judgmental cruft, you’ll find that Whole 30 is super useful for tracking down food allergies. This is because of the strong emphasis on eating mostly whole foods in the most literal sense: when you cook using food that hasn’t been processed, you can see with your eyes what is going into your body. When you cook with food that has been processed a lot, you literally can’t see what other foods are included in it, which makes it hard to track down food sensitivities. Whole 30 also already eliminates many common sources of food sensitivities, although I would suggest eliminating eggs, clarified butter, nightshades, and seeds as well.
The advantage of Whole 30 is that a lot of free resources and recipes are available online, and it doesn’t require buying a lot of new ingredients or cooking utensils. It doesn’t put any emphasis on eating animals or animal products (though in general it’s hard to eat enough calories on a vegetarian diet without grains or sugar so it will be a lot of work). The disadvantage is that it involves a lot of cooking and makes it hard to eat out. It also doesn’t include specific guidance on which foods to reintroduce when.
Whatever system you use, I recommend spending at least a month eating mostly “whole foods”: foods that are totally unprocessed and aren’t contaminated by other foods in a factory or a commercial kitchen. It will make narrowing down your food sensitivities much easier if you know what you are really eating.
Random useful stuff
FODMAPs: This is an acronym for a set of carbohydrates that are difficult or impossible for many people to digest. Instead, your gut flora digests them, producing gas, inflaming your gut, and overpopulating your gut with microorganisms. Sometimes this results in SIBO: small intestine bacteria overload, where bacteria invade the small intestine. Many people feel better when they reduce the quantity of FODMAPs they eat. Some people are much more sensitive to specific FODMAP, such as fructose. While this isn’t a food allergy, it is a food sensitivity, and fixing it will make it much easier to detect any other issues. It also can make a huge difference in your quality of life.
Probiotics: Having too little, too much, or the wrong kind of microorganisms in your GI tract can be both a symptom and a cause of food sensitivities. One form of this problemis the aforementioned SIBO, small intestine bacteria overload. The fix usually involves one or more of:
- Taking probiotics (increasing “good” microorganisms)
- Cutting down the food that “bad” microorganisms feed off
- Antibiotics to kill off “bad” microorganisms
It takes month or years to change your gut flora, so keep at it! The payoff is so worth it.
Acidity: Some folks need to eat less acid-producing foods to be healthy. Some foods don’t seem acidic but the end result of digesting them is a higher level of acid. Sugar, salt, and grains are three examples of acid-producing foods that don’t seem acidic but will increase the acidity if your body.
Supplements and drugs: If you take any supplements or drugs, they may also be triggering food sensitivities, depending on their ingredients and how they were processed. Even switching brands of supplements can trigger new symptoms if the other ingredients change. I’m currently tracking down a sensitivity to one of my supplements using binary search: I stopped all the supplements; then when I stop having the symptoms, I reintroduce half my supplements; if I have the symptoms, I cut the supplements in half; if I don’t have symptoms, I add back half of the remaining supplements. Repeat until you find the specific supplement that is causing the problem. I’ve started keeping a diary of changes to my supplements and drugs, including manufacturer changes, so that I can track the source of sensitivities sooner.
Updated to add: Anti-allergy drugs and supplements: I take several things to reduce my allergic reactions to food. There are several steps in an allergic reaction, and I take something for each step. I also take higher than standard doses on some drugs because that’s the recommendation for people with hEDS and I feel better. Talk to your doctor to find what is right for you. My current list:
- Mast cell stabilizer: sodium cromolyn (Gastrocrom)
- H2 blocker: famotidine (Pepcid AC)
- Anti-leukast: montelukast (Singulair)
- Many things: quercetin
The drugs reduce my reactions when I do eat something I’m allergic to, sometimes to the point that I don’t mind eating them (like almonds) but I generally don’t eat them anyway.
That’s a lot of what I’ve learned about finding food sensitivities and allergies! I hope it helps you find any food sensitivities you may have with the minimum of time spent feeling awful.