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Food allergy is getting a lot of buzz lately. If you experience recurring digestive issues, inflammation (like joint pain), skin issues, bloating, brain fog, or lethargy, something you are eating may be causing these symptoms. But is food allergy testing helpful to determine which foods are the culprits?

Put simply, a food allergy is an allergic response to the protein in a food. When you think food allergy, you may think of eating something that suddenly causes hives or shortness of breath, an anaphylactic response that sends you to the hospital. This type of reaction is a true food allergy called an IgE response and is classified as a hypersensitive severe immune reaction that may affect the respiratory tract or circulatory system. These food allergies are very serious, and you probably know which foods to avoid if this is you, as onset usually occurs during early childhood. The most common IgE allergies are nuts and shellfish. According to the Food Allergy & Anaphylaxis Network, only about 4% of the United States population has a true food allergy.

There are actually several different types of non-allergic but food intolerant reactions that can occur, and they can be pronounced and serious, causing inflammation and sometimes debilitating symptoms.

  • Celiac disease is not a food allergy, but an autoimmune disease characterized by a severe reaction to wheat and gluten proteins. People with celiac may also experience cross-reactivity to foods such as coffee, chocolate, corn, dairy, and other grains.
  • Non-celiac gluten intolerance is an intolerance to wheat and gluten proteins that is not autoimmune, like celiac, but still causes significant harm and reactive symptoms.
  • Lactose intolerance: some people are allergic to the proteins (casein) in milk. But up to two-thirds of the global population can’t properly digest lactose, the sugar in milk. This is not an allergy, but it’s a real intolerance, and it affects billions of people.

  • FODMAP intolerance. A growing number of people with conditions like SIBO and IBS (which affect 10 to 15 percent of the population worldwide—hundreds of millions of people) are intolerant of certain carbohydrates, called FODMAPs, found in common and seemingly random carbohydrates like onions, garlic, and higher fructose fruits.

The main and final type of food intolerance–and what I’ll be focusing on here–is an IgG reaction, referring to the IgG antibody, the largest circulating antibody in your systemThis food intolerance is often used interchangeably with food allergy, but it’s not a true allergy. The IgG reaction symptoms may be delayed up to 72 hours (whereas true IgE reactions happen immediately) and is technically a food intolerance.

What happens in this situation is that the IgG antibody marks certain food particles as antigens, and when you eat these foods, the body mounts an inflammatory immune response and attack. There is quite a bit of confusion about food allergy, food intolerance, and food sensitivity. For the purposes of this article, I am referring to IgG food sensitivity and intolerance as food allergy.  

IgG food allergy symptoms include the following

  • gas, bloating
  • headache
  • eczema
  • rash
  • acne
  • heartburn
  • fatigue
  • diarrhea
  • hay fever symptoms (itchy, watery eyes, sneezing)
  • asthma
  • insomnia
  • brain fog
  • joint pain
  • IBS or Crohn’s

Some estimates say that up 80 percent of people have IgG food allergies. Many are not aware, assuming their digestive symptoms are just a part of being a human.

Many practitioners use food allergy testing in their practices to help determine which foods are problematic. By avoiding those foods, one may lose weight, heal leaky gut syndrome, improve IBS or Crohn’s, heal eczema, and just plain feel better, because the allergy response creates inflammation that can lead to weight gain, leaky gut, and a host of other problems.

But is food allergy testing accurate?

Is Food Allergy Testing Helpful?

There are several different types of food allergy testing. The ones you’ll most frequently hear about are ALCAT and ELISA testing, both by blood. ALCAT needs a serum blood draw, but ELISA can be done by fingerprick bloodspot testing. The blood tests detect and measure the amount of allergen-specific antibodies in your blood, and both test for IgG food allergies.

When you come into contact with an allergy trigger, known as an allergen, your body makes antibodies against it. The ALCAT Test (Antigen Leukocyte Cellular Antibody Test ) identifies cellular reactions to over 350 foods, chemicals and herbs and is thought to be the most accurate. ELISA is an abbreviation for enzyme-linked immunosorbent assay and is thought to be less accurate. I’ve previously used ELISA testing in my practice, because as a nutritionist, I cannot order serum blood draws, and I do have access to ELISA bloodspot finger prick testing (though I believe you can now order ALCAT testing on directlabs.com). It is my opinion that the ELISA tests may not be very accurate. I have seen many come back completely clean when the person had a known adverse reaction to a food.

But this is where it gets confusing: even if you do not produce allergy-specific antibodies to a food, you may still experience reactions, such as bloating, when you eat certain foods. This is why I don’t believe food allergy testing to be a good choice in most cases. In my experience, one may not tolerate a food because the person cannot properly digest the food due to carbohydrate/FODMAP intolerance that accompanies SIBO, IBS, or bacterial issues in the gut, for example.

And that’s where the situation gets muddy: the food intolerance may not show up on a test because there is no reaction to the protein, but the person may still experience digestive symptoms with certain foods. In the case of SIBO, for example, bacteria in the small intestine (where they don’t belong) ferment carbohydrates when you eat them, and that results in constipation, diarrhea, bloating, belching, or heartburn. So, many people think that have allergies to the foods that cause these reactions when in reality, they have bacterial overgrowths or dysbiotic bacteria that ferment the starches they eat and produce unpleasant reactions.

In addition, IgG antibodies are found in both allergic and non-allergic people. Experts believe that the production of IgG antibodies is a normal response to eating food and that food allergy tests are not helpful in diagnosing a food allergy. This article claims thatthere are no reliable and validated clinical tests for the diagnosis of food intolerance. While intolerances are non-immune by definition, IgG testing is actively promoted for diagnosis, and to guide management.”

The ALCAT food allergy test gives you a report of all the foods you react to: severe, moderate and mild category. For many, sometimes hundreds of foods can show up across these categories, and that can be very overwhelming. It’s recommended to avoid certain foods in rotation and for specific amounts of time, which, again, can be overwhelming. In my experience, my clients have stressed so much about sticking to their rotation and exclusion plan that they become afraid to eat, which is a damaging place to be mentally. I typically have them avoid the foods in the severe category only.

All that said, I have seen some positive outcomes from avoiding foods on food allergy testing– in the severe category typically. Avoiding these foods for at least six months allows the gut to heal and seems to reduce inflammation, which can heal chronic conditions. I’ve also seen incredible reversal of eczema and autoimmune conditions.

Be aware also that foods that show up mean you may be reacting to those foods right now due to leaky gut. Once your gut heals, you may be able to tolerate those foods again. So don’t get discouraged thinking you’ll have to avoid 100 foods for the rest of your life. The test results are letting you know what you’re reacting to currently. Some of these reactions may be inborn allergies, and some may be a result of leaky gut.

So where does that leave us? Most often, after analyzing a client’s food journals and his or her symptomology, I can determine which foods I think are problematic, and I’ll recommend a food allergy elimination diet. I often think that is more accurate (and a lot cheaper) than food allergy testing— simply avoiding the foods you think may be problematic, then reintroducing them one at a time after a month or so. If you react to a certain food, you may have an intolerance or you may not digest that food well, so avoid it for six months, heal the gut, and try again. The most common culprits are gluten, dairy, eggs, soy, corn, nuts, and nightshades.

Long story short: I don’t recommend food allergy testing as a first step. It can be overwhelming and overly exclusionary to avoid scads of foods (those in the moderate and mild categories typically), not to mention it stresses people out. I’ll often suggest trying the food allergy elimination diet route initially, and if symptoms and problems persist, I then recommend testing. I use this lab (the link gets you 15 percent off the kit, which is an easy fingerprick test that you can do at home) and have the person avoid the foods in the moderate and severe category for 3-6 months.

The above scenario is when food allergy testing is effective: When a person has an allergy to a random food (like onions or kale) that she or he consumes regularly. You’ll probably never figure that out on an allergy elimination diet. Or the person has tried allergy elimination diets and symptoms do not improve. Eliminating the foods that show up (that are often random foods the person consumes regularly) reduces inflammation, symptoms subside, and the person feels better, but it would be impossible to know what without testing. As with everything in holistic healing, I take every case into consideration separately before making recommendations.

Want to try at-home food allergy testing? I use this lab, and you can order a kit for 96 foods yourself.

I’d like to hear from you. Have you had food allergy testing? What was your experience?

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