Understanding Food Allergies and Food Sensitivities
By Sarah Axtell, ND • April 25, 2014
If you suffer from chronic constipation, diarrhea, gas, bloating, headaches, acne, eczema, psoriasis, anxiety (really, the list could go on and on), you may have an underlying food sensitivity. Most people know if they are allergic to a food, such as peanuts or shellfish. But food sensitivities often get missed. Below are some basics of food allergies and sensitivities.
Terminology: Food Allergies, Food Sensitivities, Food Intolerances
What is a food allergy?
When we hear the term “food allergy” we often picture a person covered in hives, swollen beyond recognition, and gasping for air. This certainly can be the case, especially in the case of shellfish or peanut allergies. An allergy is an IgE mediated immune response and occurs shortly after the food is ingested (minutes to hours after exposure). Symptoms include hives, lip swelling, and anaphylaxis.
How are food sensitivities different from food allergies?
Many individuals do not have severe, life-threatening reactions to the food they eat, but they may be experiencing less obvious symptoms that they are unable to recognize. In the examples mentioned above, the reaction to the food is usually fairly immediate; however, in the case of food sensitivities, the reaction may be what is known as a “ delayed hypersensitivity reaction,” and the symptoms may not occur until 1-3 days after the initial exposure. As the body reacts to the food, it triggers an IgG mediated immune response. As you continue to eat the same foods, your immune system is continually activated. This constant activation of the immune system may result in chronic inflammation and can lead to chronic, autoimmune and degenerative diseases.
What is a food intolerance?
Unlike food allergies and food sensitivities, food intolerances do not involve the immune system. They can result from poor digestion due to lack of or low enzyme levels, as in the case of lactose intolerance where an individual lacks lactase enzyme to break down milk. Food intolerances can also be an adverse chemical reaction to naturally occurring components in foods or their preservatives, such as with histamine intolerance or sulfite sensitivity.
Why do food allergies or food sensitivities occur?
As a naturopathic doctor, I am always asking “Why?” Here are some of the most common causes of food sensitivities or allergies:
1. Stress– When your body is in a state of stress, the priority is not to digest. Rather, your body is essentially in a state of survival. When you are stressed, your blood is primarily going to your heart and lungs for survival (ie. to run away from a predator). Your blood is not going to your gut to promote optimal digestion. This is where food hygiene comes in- sitting down when you eat, chewing your food, turning the tv and computer off, and simply focusing on your food. When you eat in a relaxed, peaceful environment, you can digest your food, which will lower your susceptibility to food allergies.
2. Genetics– You may be biased toward a particular immune response (such as a peanut allergy past down from your parents). However, we cannot chalk everything up to genetics. While you may have a certain gene for an allergy, that does not necessarily mean that you will express that gene. Our environment (diet and lifestyle) can impact whether or not we express a gene. This is called Epigenetics.
3. Microflora– If you have dysbiosis (overgrowth of “bad” or pathogenic bacteria), this can impair your digestion. When we do not break down food properly, this can lead to an increased risk of allergies or sensitivities. Taking a daily probiotic with at least 10 billion CFUs can help.
4. Acid Reducing Medications– Antacids, such as Nexium, Prevacid, Zantac or Pepsid, reduce your body’s production of stomach acid, or HCl. Stomach acid is essential for digesting proteins. If you have undigested proteins in your gut, this will lead to more of an antigenic immune response. This immune response to food is most commonly an IgG immune mediated response, which is termed a food sensitivity.
5. Quantity of undigested food– If you are over-eating a certain food multiple times a day and have poor digestion to begin with, you are more likely to start reacting to that particular food. Dairy and gluten are very common food sensitivities, but you can start reacting to any food if you have impaired digestion and are over-doing one particular food. If you are over-doing almonds for instance (ie. almond butter, almond milk, almond flour, snacking on almonds), you could potentially start reacting to almonds. This is a nice reminder to rotate your foods.
Factors that Contribute to Food Allergies or Sensitivities in Kids
1. Birth– Babies born via C-section do not get exposed to mom’s vaginal flora that normally inoculates baby’s digestive tract. Thus, babies born via C-section have an increased risk of allergies.
2. Mom’s diet- If mom’s diet is high in a particular trigger food (such as gluten or dairy) while pregnant and she is in fact sensitive to that food, she may be passing that sensitivity on to her child.
3. Breastfeeding- Breastfed babies have stronger immune systems and tend to have less allergies.
4. Timing of food introduction– Adding certain allergenic foods into a baby’s diet too early or too late can predispose him or her to food sensitivities or allergies.
Symptoms of Food Sensitivities (IgG Mediated Food Reaction)
I by far see more food sensitivities in my practice than I do food allergies or intolerances. Almost any system in the body can show a reaction to foods. Some symptoms include:
- Urinary irritation (recurrent UTIs, bladder spasms, Interstitial cystitis)
- Rashes (eczema and psoriasis)
- Chronic sinus or ear infections
- Tinnitus (ringing in the ear)
- Nasal congestion
- Brain fog
- Joint pain
- Mood disturbances (anxiety, depression)
Most Common Sensitive Foods
- Citrus fruits
Testing for Food Allergies and Food Sensitivities
Food Allergies (IgE) are generally tested by an allergist with a skin prick test. If you think you have an issue with a food and there was no positive reaction, then the food reaction is not IgE mediated. It is likely an IgG reaction, or a food sensitivity.
Food sensitivities can be determined by an elimination challenge diet or a blood test. An elimination challenge diet is a trial diet where you eliminate the top sensitive foods- gluten, dairy, corn, soy, eggs, citrus, and sugar. The elimination phase must last at least 4-6 weeks because that is how long the IgG protein lasts in the body. After the 4-6 weeks elimination phase, then you can add one food back in at a time and assess for a reaction.
The alternative to the elimination challenge diet is to do a blood test. This is more comprehensive because we can test for your IgG immune reaction to 96 different foods (as opposed to just evaluating for the top 7 food triggers when doing the diet). The test is commonly performed by naturopthic doctors. Medical doctors do not routinely administer this test.
Assessing for food sensitivities has been an invaluable part of my practice. If you have chronic and persistent symptoms, talk with your naturopathic doctor about working you up for food sensitivities.
Editor’s Note: The information in this article is intended for your educational use only. Always seek the advice of your physician or other qualified health practitioners with any questions you may have regarding a medical condition and before undertaking any diet, supplement, fitness, or other health program.