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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.  She’s frustrated and lost. Can you help me in any way? There are three panels with Low, Moderate and Avoid results. 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)!  What am I missing?

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” (which can progress to officially be “type 3 hypersensitivity”) 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 consumed (and perhaps quite healthy!) food with hypervigilance.  Important information, but one that is not as targeted as we might assume.

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).  Similarly, someone may have an outright (even violent) allergy to a food and thus generate significant IgE antibodies in reaction to that food, but there may be no IgG or IgA 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, chemical additives, and other triggers in food which will not show up on a typical food antibody panel.  And going back to Total IgG measurements, note we can have high levels of these antibodies simply due to high consumption, and there may be little/no complement activation to trigger an inflammatory response.  Bottom line: this complexity can make it hard to “nail down” food sensitivities/allergies clearly via a lab test.  And it’s one of the reasons why the “gold standard” of identification of these issues is through 100% food elimination followed by a reintroduction challenge.

Sure, testing can be helpful!  But only as one puzzle piece.  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 many precautions to anticipate and weed out false positives.  Cyrex also makes the provision 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.  Vibrant Wellness also offers a series of test panels which test for both IgG and IgA reactions.  My second choice in food sensitivity testing would be KBMO which measures IgG antibody specifically in immune complexes with complement (which dramatically helps eliminate false positives but may have false negatives).  This one is notably less expensive but still a sizable investment.  For patients who can afford to do so, these are excellent choices.  There are also high quality Total IgG panels (more vulnerable to false positives) from functional lab companies such as Genova and Alletesse. But the point I made above is key here:  none 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 negatively to foods, including mechanisms that don’t involve antibodies or measurable immune reactivity.  Testing can be valuable for some clients but is not always necessary.  Again, the gold standard is food elimination and structured reintroduction.

A test called 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 (including myself) 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).

But back to your client!  In my experience, the best way to eliminate the effect of the severe IgG-mediated food sensitivities is to eliminate them 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 likely 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).  The “Low” foods are likely 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 most severe sensitivities cold-turkey (*and* prioritize calming the immune system and healing any enhanced intestinal permeability in the interim), 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 which given the average half-life of IgG antibodies will render their level to <10% of their original amount.  Of course, during those precious three months, we must, must also work on addressing the root causes of the immune hypervigilance!  Assess and explore sleep, movement, insufficient nutrients (especially Vitamins D and A and zinc), stress, toxic exposure/overload, enhanced intestinal permeability, and microbiome imbalance.  We must shift the environment overall that our immune and nervous systems are responding to if we wish them to have a more tolerant response to our foods.   Just eliminating the foods is not enough!

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 Severe and Moderate foods right away, then start with all the Severe 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-IgG-ranked foods due to maldigestion vs. any type of immune response.

If she has many Severe category foods and most of them are foods she eats often, then it’s likely that she has Enhanced Intestinal permeability (aka Leaky Gut), a situation in which the immune system has extended exposure to semi-digested food in 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 event with alarm (maldigested food is on the wrong side of the intestinal “fence”!).  I have written many times 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, Vitamin D deficiency, and chronic stress – all potentially very damaging to the gut.  In the case of leaky gut, people tend to develop sensitivities to the foods they consume most often (simply due to more frequent exposure).  It’s important to heal the excessive permeability while eliminating the foods, or an individual is likely to develop a follow-on set of sensitivities to the new foods they are choosing (alas, I’ve worked with several clients with poly-autoimmune disease who had experienced this frustrating cycle).  After she begins eliminating the foods fully, I recommend you consider all of the following, important steps:

  • take 3 grams of L-glutamine twice daily on an empty stomach to help heal the villi junctions in her small intestines e.g. Metagenics “Glutagenics” or Designs for Health “G.I. Revive” which also feature a number of other herbal agents which can help to heal the gut lining e.g. slippery elm and aloe.  In some few cases (~5%), taking l-glutamine can increase anxiety or irritability in very sensitive patients, so be on the lookout for this just in case.  Quercetin is also valuable for this purpose (e.g. 500mg, 1-2x daily).
  • check her vitamin D and ensure it is at least 40-50 ng/ml  (low Vitamin D encourages leaky gut).  If not supplement with Vitamin D3 to raise it (starting with 1000-2000 IU/day and progressively increasing as needed), but be sure to replete magnesium first as it is needed to convert Vitamin D to its final form.
  • take a daily probiotic to help calm and balance her immune system (e.g. lactabacillus rhamnosus or plantarum).
  • 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 a cause of leaky gut and erosion of the protective mucosal lining of the intestines

After she has fully eliminated a food 100% for at least 3 full months, 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 careful attention to any inflammatory response from her body during those 3-4 days.  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 likely fine to resume eating that food (in a well-balanced diet).  Take at least a few-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.

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

  1. 6
    Anu Ramesh says:

    This question is regarding Liver and gall bladder supplements. When someone is having biliary symptoms like indigestion and dyspepsia – What would you recommend to improve bile secretion? I am debating Milk Thistle vs Chanca piedra. Liver With regards to detox some people say colon detox before liver – But you mentioned that insufficient bile is a cause of constipation. Since they are so linked together – I am confused about which one to give first.

    • 6.1
      SAFM Team says:

      First, let’s not forget that indigestion and dyspepsia can be also caused by low levels of stomach acid and/or low pancreatic digestive enzymes output, or by dysbiosis, or simply by poor eating hygiene.
      If it is a biliary issue then the question is whether the bile production quality or flow or both are at stake and you’d support those in a slightly different way. There’s an existing post on the gall bladder rescue that speaks to the benefits of D-limonene to improve bile flow:
      In terms of the bile production quality, one needs to ensure proper liver (and thyroid) function and this can be supported via diet with and specific cholagogue herbs, such as artichoke leaf extract, aloe vera, ginger, dandelion, and milk thistle to name a few. As for Chanca Piedra (Phyllanthus niruri L.), there is more research on its benefits for the liver. You may be interested in this article:
      I’m not sure what you mean by ‘colon detox’, but you certainly want to ensure regular and easy bowel movements before trying to upregulate liver detoxification pathways. We have a whole separate deep-dive clinical course on this topic if you are interested.

  2. 5
    Miriam 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.

  3. 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.

  4. 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.

  5. 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.

  6. 1
    Kathleen 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 Team 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. ).

      • 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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