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Food Sensitivities: What, Why, and How

(This is a sample entry from our Q&A Treasure chest, a database with hundreds of entries to support students with their client needs…  Unlimited access is included as part of our Core 101 Semester program.)

Student Question:

Hi Tracy!

I have a new client – a  46-year-old lady who is literally allergic/sensitive to every good edible food, it seems!

Her doctor did an ELISA Basic Food Panel, and there is nothing for her to eat!  I have no idea what to do. To put her on any kind of detox to clear out her gut is impossible because all the foods that are good for detox she cannot have. She’s frustrated and lost. Can you help me in any way? There are three panels with Low, Moderate and Avoid. Now, if she is ‘sensitive’ to foods, wouldn’t they also irritate her? She has a few foods in LOW, but they are not foods she enjoys or can even ‘stomach’, such as fish, due to their strong smell. Surprisingly, she had no intolerance to all the sugars, corn starch, and MSG (at least on this test)!

Tracy’s Answer:

Great question!  First of all, I encourage you to confirm exactly what type of food sensitivity testing was performed.  For purposes of this reply, I am going to assume that this was a Total IgG food antibody panel which measures sensitivities and are a marker of the adaptive immune system’s reactions to foods.  Essentially, the test is measuring when the immune system is reacting to a common (and perhaps quite healthy!) food as though it were a foreign invader by developing antibodies.  And you are absolutely right that she needs to heal these sensitivities before she can use those foods for any type of cleanse.  A cleanse is a great idea, but one step at a time – in the right order – will allow the right kind of healing.

First of all, it’s important to realize that no single food allergy/sensitivity/intolerance panel is going to yield a comprehensive and fully accurate list of all foods that might be causing inflammation and/or discomfort in your clients.  IgG antibodies are only one type of reaction that the body can have to a perceived threat (e.g. a food).  We can also have an IgA-mediated response (which happens in the mucous membranes of the body, such as the gut lining).   The other (larger) half of the immune system is innate immunity which might also be reacting to foods and causing her discomfort/inflammation (and does not produce antibodies).  Similarly, someone may have outright (even violent) allergies to a food and thus generate large amounts of IgE antibodies in reaction to that food, but there may be no IgG antibody generation.  Food intolerances such as lactose or fructose intolerance are not reactions from the immune system at all, but your client will still suffer from consuming these foods.  The body can also react to lectins, mycotoxins, and other triggers in food which will not show up on a typical food antibody panel.  Bottom line: this complexity can make it hard to “nail down” food sensitivities/allergies clearly.  And it’s one of the reasons why the “gold standard” of identification of these issues is through 100% food elimination for 2-3  months followed by a reintroduction challenge.

A test called the ALCAT (and its refined follow-on, Mediator Release Testing (MRT)) is designed to assess the body’s innate immune system response to a food.  Some practitioners use these panels with great results; others question the lack of clinical study validating their accuracy and repeatable results (and our overall ability to assess innate immune system sensitivity to foods in general).  I personally do not use ALCAT testing in my practice at all.

I believe the current best-in-class food sensitivity test is available from Cyrex (Array 10, specifically) which measures a combination of both IgG and IgA while taking a lot of precautions to anticipate and weed out false positives and also taking the step to ensure foods are tested in the form in which they are usually consumed (i.e. cooked vs. raw chicken and raw vs. cooked banana).  However, this test is quite expensive.  My second choice would be KBMO which measures IgG antibody specifically in immune complexes with complement.  Again, this one is also usually more expensive.  For patients who can afford to do so, these are excellent choices.  but the point I made above still applies:  neither of these tests is fully comprehensive for all inflammatory reactions to foods.   There is no such thing.  The body has MANY ways in which it can react to foods, including mechanisms that don’t involve antibodies.  Again, the gold standard is food elimination and structured reintroduction.

Otherwise, where funds are a strong limitation and testing is still desired, I often recommend choosing IgG4-specific testing vs. Total IgG.  Lots of functional medicine practitioners will disagree with me.  Here’s my rationale:  IgG4 testing will minimize the possibility of false positives and the need for your client to “over eliminate” in order to be sure to get at the true inflammatory culprits.  Absolutely, the IgG4 results are unlikely to be comprehensive.  In the absence of specific immunotherapy to counter IgE-based allergies (which purposefully elevates IgG4), testing specifically for IgG4 will indicate sensitivities that the immune system has been responding to persistently.  IgG4 itself does not trigger inflammation (via complement) but rather better indicates antigens to which IgG1 has been responding for some time (which tends to screen out immune responses simply to overconsumption of a food).   There is the possibility, however, that using IgG4 will miss other sensitivities (that would be caught with a Total IgG panel).  But of course, there can be IgA reactions as well as other antibody and non-antibody driven reactions.   Indeed, there is no ideal testing for this dynamic (are you getting that point? 🙂 ).  One can always start with prioritizing eliminations of high IgG4 foods and then later test for Total IgG or more comprehensive panels to determine additional opportunities.

But back to your client!  In my experience, the only way to thoroughly eliminate the severe IgG-mediated food sensitivities is to eliminate it for a time.  Not just reduce it.  But rather 100% eliminate it – cold turkey – for a time to allow IgG antibodies to disappear and then reintroduce the food.  I believe she needs to eliminate all the Severe and Moderate sensitivities 100% for at least 3-4 months initially (perhaps longer but this is a good starting point).  Personally, I think the “Low” foods are fine for her to continue to eat occasionally (1-2x/week) but not every day, so be sure to have her look through the list carefully and decide what foods need more rotation.   The good news is that if she can eliminate her sensitivities cold-turkey, there is a very good chance she will be able to reintroduce all or nearly all of them with no effects after a few months (and thus be able to add them back into her diet).

I usually recommend a 4-month elimination because it usually takes the client a few weeks to fully eliminate them (and officially “start the clock”) and get in a true 3 months of full elimination.

Your opportunity is to help her creatively to find alternative, healthy foods that she can use to nourish herself over the next few months.  Reassure her that this is not “forever” – just for a healing window.  If she feels she cannot eliminate all the Avoid and Moderate foods right away, then start with all the Avoid items, at least as a starting points.  Some clients needs a little time to develop new habits/choices and progressively move into the full elimination.

Keep in mind that the development of a sensitivity is not an indication in any way of the “healthiness” (or toxicity) of a food – just a measure of her unique immune system’s response to it.  And she may feel uncomfortable after eating some low-ranked foods because her body’s reaction is more digestive in nature (vs. immune).

If she has many Avoid category foods and most of them are foods she eats often, then it’s likely that she has Leaky Gut, a situation in which semi-digested food leaks through and has extended exposure to our immune system “police station” in the gut lining (called our “GALT”, gut-associated lymphoid tissue).   Obviously the immune system is going to react to this even with alarm (food is on the wrong side of the intestinal “fence”!).  I have spoken before about intestinal permeability, and this post might be helpful.   Unfortunately, this situation is not uncommon given our cultural bias toward large use of antibiotics, over-the-counter painkillers, and chronic stress – all very damaging to the gut.  In the case of leaky gut, it’s important to heal the permeability while eliminating the foods, or the sensitivities will not go away permanently.  After she begins  eliminating the foods fully, I recommend she do all of the following, important steps:

  • take 3 grams of L-glutamine powder twice daily on an empty stomach to help heal the vili junctions in her small intestines (I most often recommend Metagenics “Glutagenics” or Designs for Health “G.I. Revive” which also features a number of other herbal agents which can help to heal the gut lining e.g. slippery elm and aloe).  In a very few cases, taking l-glutamine can increased anxiety or irritability in very sensitive patients (likely due to a leaky blood-brain-barrier), so be on the lookout for this just in case.  Quercetin is also valuable for this purpose (e.g. 500mg 1-2xf daily).
  • check her vitamin D and ensure it is at least 50 ng/ml  (low Vitamin D encourage leaky gut).  If not supplement with Vitamin D3 to raise it.
  • take a daily probiotic to help calm and balance her immune system (e.g. Ultimate Flora “Adult” formula)
  • avoid eating gluten entirely (even if it’s not on her sensitivity list).  In some people, gluten can promote increased intestinal permeability through increased secretion of a protein called zonulin.
  • avoid all alcohol
  • avoid taking all over-the-counter anti-inflammatory “NSAID” medications (e.g. Advil, Aleve, Tylenol), as these are often the cause of leaky gut after protracted, regular use
  • start taking some type of multi-faceted liver detoxification support supplement (e.g. Metagenics “Advaclear” to help the body to upregulate phase 1 and phase 2 detoxification – toward reducing inflammation systemically)

After she has fully eliminated a food 100% for at least 3 months (again, I prefer 4 – for greater chance of success), she can do a “reintroduction challenge” of one food at a time.  Let’s say one of her sensitivities is to broccoli.  While continuing to eliminate all other sensitivities, she can “challenge” her immune system with broccoli by consuming two normally-sized servings twice during the day for three days in a row.  Then stop.  Not little bites here and there – real, full servings (~1 cup).  Have her pay very careful attention to any inflammatory response from her body during those three days (or the day or two afterward).   Symptoms may include reactions like headache, acid reflux, strong fatigue, brain fog, eczema, aching joint, sustained nasal congestion (or post nasal drip with clearing of throat).  Note that it might be physiological or it might be purely neurological.  If there is no reaction, then she is fine to resume eating that food (in a well-balanced diet).  Take at least a 3-day break in between each new food challenge, and only challenge one food at a time.  After ~4 months, I find most foods can now be tolerated.  However, there is often a food or two that requires a further elimination (for a total of  6-7 months).   Very occasionally, I find there is a food that simply cannot be successfully reintroduced, even after a year of elimination; these are likely permanent sensitivities that simply need to be avoided long-term.


11 Questions for “Food Sensitivities: What, Why, and How”

  1. 5
    Mirima Zimela says:

    I have been ordering gluten sensitivity antibody test for my patients and the result has been showing level of transglutaminase IgA, and IGG that are not high enough. What does this indicate with regard to gluten sensitivity?

    • 5.1
      SAFM Team says:

      First, keep in mind is that in order for these antibodies to be detected, a person has to be eating gluten-containing foods. If they have been avoiding those for a while the antibodies will not come up high. If a person is consuming gluten-containing foods AND the antibody tests come back lowish I’d consider the following:
      1) There are many situations in which people’s overall IgG and IgA antibodies are not high enough and this is the reason why the results come back low. The reasons for low antibody levels could be:
      – allergy medication or on the steroid medication – both mimic the cortisol and can result in the immune suppression.
      – low immune function due to lack of nutrients (think low Vit D and A, zinc, etc.)
      – low thyroid function (gut issues; toxicity; estrogen dominance)
      – low adrenal function (chronic stress of any origin)
      As you can see these issues are quite ubiquitous and potentially affect a large portion of the population.

      2) Please note that the transglutaminase IgA gets elevated primarily in the gut mucosa and may not be reflected in the blood. In addition to this test you may consider testing for the Endomysial antibody (EMA test) which is another marker to determine gluten sensitivity. This review goes in depth into the differences between the transglutaminase and the endomysial antibodies:

      3) No test is perfect, even if the results come back ambiguous and a person still suffers negative symptoms when consuming gluten it is an obvious sign of sensitivity to that food, so the elimination diet can be very helpful.

      4) Some people choose to undergo an endoscopy to determine the extent of gut damage, however, there also could be no gut damage but gluten/wheat sensitivity that causes an inflammatory response in a client. This is another great opportunity for the elimination diet.

  2. 4
    SAFM Team says:

    Since you have already seen this post, you might also appreciate this one: . It is a not a “food sensitivity” but rather an intolerance, closer to the concept of lactose intolerance. A person may wrestle with histamine intolerance for rich variety of reasons. If they don’t have sufficient enzymes/microbes in the gut to have optimal levels of DAO enzyme to break down histamine, then they can be overloaded simply by histamine naturally present in foods. However, one can also have histamine intolerance because there is a dynamic *internal* to the body driving strong synthesis of histamine, and the body’s methylation capability is unable to keep up. The half-life of IgG antibodies is about 21 days.

  3. 3
    Tammy Valta says:

    What would be a good probiotic for a woman with gluten intolerance (she gets bloated every time she has wheat and experiences acid reflux as well)? She is also taking an antidepressant, was 10 years on metformin and Glucophage, and is still quite overweight. Thank you.

  4. 2
    sharon chud says:

    After a 10 day use of an antibiotic for a sinus infection what would you recommend to replace the intestinal flora? Should I replenish the flora first or go right into no probiotics to prepare for the SIBO test?

    • 2.1
      SAFM Team says:

      Generally, it is best to begin taking a probiotic in advance of starting an antibiotic course – to help prime and balance the immune system reaction. I usually recommend a Lacto/Bifido blend that also includes S. Boulardi e.g. Metagenics UltraFlora Acute Care, starting asap before the antibiotic course, continuing through it, and then extending for another ~6 weeks. Keep in mind that your antibiotic use has undoubtedly dramatically affected whatever SIBO was present; the overgrowth may or may not still be present and likely cannot be accurately assessed for quite a while. It may be quite logical, instead, to just support the gut’s recovery with the probiotic, focus on optimizing eating hygiene (e.g. no grazing) and digestion (e.g. chewing!), optimizing diet and immune system function, and seeing over the next several weeks if SIBO is actually still a part of your life or not. Future testing may not even be necessary.

  5. 1
    Kathleen Mitchell says:

    Hi Tracy,
    I know we always talk about IgG in terms of food sensitivities but what about someone that is IgG deficient? I am trying to support a man that is deficient and his immune weak and was given injections for years with globulins but no longer receiving them. Thanks, I just don’t think of it from this angle.

    • 1.1
      SAFM says:

      Total IgG level can be measured in blood. If an immune system is calm and at rest, their overall IgG levels will be moderate, an indication that the immune system is well-primed. One can end up with low levels due to persistent immune challenge (e.g. Lyme disease, EBV) or genetic factors. Indeed, someone may have food sensitivities but with very low levels of IgG, and their lab sample may not trip the threshold of significance to show up on a test. A great reminder that there are limitations to any and all labwork markers. In terms of boosting adaptive immune function to support a lower IgG level, I would consider the importance of optimizing immunity nutrition (e.g. D, A, Zn), stress relief, ample deep sleep, and ensuring a healthy microbiome. I would also consider regular use of colostrum as a supportive supplement (or if need to be dairy-free e.g. ).

      • Jodi Franklin says:

        If someone takes an IgG food sensitivity panel, such as the Food-Safe Allergy Test, and it shows no sensitivities, but the client has an autoimmune disease (I have had three clients show no sensitivities, but one had Colitis and the other two have Vitiligo), does that mean they could still be having IgG reactions to food, but it’s just not showing up doe to immune system challenges/genetic factors? If so, is there any test that can better identify these reactions?

        • SAFM Team says:

          There are several scenarios potentially at play. First of all, a client may have suppressed ability to form immunoglobulins – either innately or due to drugs; this is often the case with AI patients as immunosuppressant drugs they are typically using to control the disease will suppress immunoglobulin synthesis by definition and make food sensitivity testing a waste of time. Even if there are no steroidal or immunosuppressant drugs at play, be sure that their globulin level is at least mid-normal (in RR) as a rough check. They may also have food sensitivities that are not driven by IgG reactions (perhaps IgA, such as the case in celiac disease), and they may have sensitivities not driven by the adaptive immune system at all. As I note in the article below, there is no such thing as a “comprehensive” food sensitivity test. Just keep in mind that the choice to recommend an AI patient fully eliminate gluten – and perhaps dairy and all grains – is much more about preventing more intestinal permeability via more zonulin release (which is not an antibody-driven issue) than it is about food sensitivities. These are two separate issues. As I said above, I believe the current best (though quite expensive) test for food sensitivities is the Cyrex array # 10.

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