natural medicine

Food Allergies and Food Sensitivities

By Naturopathic Doctor Amy Neuzil.


Food allergies and sensitivities are extremely common and the symptoms are different in every person, which makes them difficult to diagnose. There are two different types of food allergies and one is easy to detect, one is not.

The first type is anaphylactic or "true" food allergies – this is what people normally think of as a food allergy. These reactions show up immediately after eating and are often very dramatic, such as swelling, hives, welts, or asthma attacks. These foods must be avoided completely because this type of food allergy can be life-threatening (swelling in the throat can interfere with breathing). Typically this type of reaction is seen in foods like peanuts, or shellfish.

The second type is called a food sensitivity reaction and these are responsible for a host of symptoms that can follow different patterns in different people. This is the type of food allergy that we will discuss in this section. Symptoms can include:

  • Neurological: brain fog, mood swings, anxiety, depression, attention deficit symptoms, behavioral problems, and sleep disturbance, memory loss, dementia.
  • Gastro-intestinal: gas, bloating, rectal bleeding, constipation, diarrhea, poor absorption.
  • Respiratory: chest tightness, phlegm, wheezing, chronic cough.
  • Dermatological: eczema, psoriasis, rashes, itching, acne, puffy bags under eyes, dark circles under eyes.
  • Musculoskeletal: muscle and joint pain, inflammation, trigger point tenderness.
  • Hormonal: PMS symptoms, can make hyper/hypothyroid symptoms worse, increased tendency towards insulin resistance or pre-diabetes.
  • Immunological: decreased ability to fight infections, delayed recovery time.
  • General: fatigue, mouth ulcers, headache, low-energy, nutritional deficiencies, obesity, weight gain.


The symptoms associated with food allergies usually:

  1. Get worse with age
  2. Do not occur immediately after eating and are often constant (because the food is eaten regularly)
  3. Can be triggered by stress, trauma and life events
  4. Resolve well with prolonged food avoidance, but sometimes require additional treatment.

The reactions are delayed because they occur through a different immune pathway than normal allergies, so it is difficult to associate them with foods because they may happen up to 3 days after eating the food. Also if the reaction is happening to a food that is eaten on a daily basis, there may never be a clear beginning or end - the symptoms are ongoing. The four most common food allergies are: wheat, dairy, corn and soy. Other common allergens are nightshade vegetables (tomatoes, potatoes, peppers, eggplant), eggs, beef, citrus, and gluten (which is in wheat but also in rye, oats, kamut, barley and spelt).

Causes and Associated Factors:

Causes of food intolerance are largely unknown, but there are many contributing factors. Genetics play a part and often if a parent or grandparent has a food sensitivity than the children are more likely to have the same sensitivity. Also we know that food sensitivities may be triggered later in life by a stress or trauma, which suggests an emotional or stress-hormone related component. We also know that food sensitivities get worse with age, which may mean that ongoing damage is occurring which contributes to the problem.

Food processing may also contribute to food sensitivities in that the most common foods that people react to are also highly processed. Milk and dairy products now are pasteurized, homogenized and have added chemicals that milk a century ago did not have. Likewise corn, soy and wheat have all been genetically modified and selectively bred to increase harvest yields in commercial farming. Many people theorize that this level of processing within the food has made it less digestible in general and may have led more people to become sensitive to these foods.

Food sensitivities are highly linked to a syndrome called Leaky Gut Syndrome, which is a situation in which some stressor (such as a food to which the patient is sensitive) causes damage to the intestinal lining. That damage allows larger than normal food particles to cross into the blood stream. Those particles trigger an immune reaction in the body because they are not supposed to be in the blood stream to begin with. This immune reaction often cross reacts with the person's own tissue, setting up a cascade of symptoms, such as the food sensitivity symptoms as well as autoimmune symptoms. Food sensitivity and leaky gut have a chicken-or-the- egg type relationship because it is unclear which condition arises first and which is a consequence. It is certain, however, that to fix either problem, you must address both.

Lab Testing (Conventional and Alternative):

Elimination Diet: This is the gold-standard in food sensitivity testing. Elimination diets require a commitment and some energy from you, but are reliable, easy to interpret and free. For full instructions on how to do a food allergy elimination please download the handout in the Client Handouts section under the "About Us" tab or see below in the "basic starting strategy" section.

Skin scratch tests: This type of test detects foods that will react with anaphylaxis – that is the instant reaction of hives, swelling or asthma-type symptoms. Skin tests DO NOT test for delayed food sensitivity reactions.

Blood testing: There are many types of blood tests for food allergies, and at Excelon we use both ALCAT testing (for patients with more severe disease) and also Eliza testing for the typical patient. It should be noted that none of the blood tests are as accurate as the Elimination Diet, which is by far the best measure. The blood tests are useful as a rough guideline but can not be trusted 100%. Results have been shown to vary depending on which lab is used and what the patient has eaten recently.

Conventional Treatment and Side Effects:

There is no conventional treatment for food sensitivities at this time – medical doctors have been slow to recognize the link between slow-acting food response and health problems.

Nutritional Associations:

Food sensitivities can occur with any food – even foods that we normally think of as "good for you." The most common allergens and the most problematic are wheat, dairy, corn and soy. People with more serious inflammatory diseases such as fibromyalgia, psoriasis, eczema, migraines or autoimmune disease are often more sensitive to foods than the general population. If the food sensitivity has been present for a long period of time, then often damage has been done to the gut lining that may have compromised digestion and nutrient absorption. For that reason it is best to use a digestive enzyme with meals as well as a high-potency multi-vitamin, and a balanced oil supplement such as cod liver oil, borage oil or a mixed oil product.

Alternative Treatments:

Obviously the best treatment for food allergies is first discovering what those allergies are and second, eliminating those foods that are bothering you from your diet. If you are treating food allergies in association with something else (such as chronic pain, autoimmune disease, skin disorders or ADD) then it is most useful to establish an integrated protocol with your doctor to deal with the food sensitivity as well as the inflammation and symptoms.

What You Can Do:

1. Discover your sensitivities: If it is at all possible, an elimination diet will give you the most accurate results. Elimination diets take some commitment on your part, but are well worth it in the long run.

The procedure is simple; eliminate the food you would like to test completely for two weeks, reintroduce the food for a day, and then watch for reactions. I have found it easiest to eliminate all four major food allergies at once and then test them (challenge) one at a time.

Let's take milk, for example. For a two-week period, avoid all products containing milk. This includes the obvious (milk, cheese, yoghurt, butter) and also the hidden, so check the ingredient list on products like crackers, cookies, bread, cakes, snack foods and salad dressings. It is extremely important that milk and diary be eliminated completely so that your immune system has a chance to stop reacting to it. During this period you will probably not notice a change in your symptoms – that is completely normal.

After the elimination period, we have a challenge day. The goal this day is to eat lots of milk or dairy ingredients so that your body is given a chance to respond. After milk day, stop eating dairy again and watch for symptoms for the next four days. In this period people who have some milk sensitivity will report symptoms like increased nasal drainage, increased joint pain, irritability, depression, mood swings, aggressive behavior, poor digestion and "brain fog. " It is also possible that the system is affected by the reintroduction day enough to become ill, typically some type of viral illness. The display of any of these signs or symptoms is considered a positive reaction.

  • Eliminate the food to be tested completely for two weeks
  • Reintroduce the food for one day
  • Eliminate the food again and watch for signs, symptoms or illness for the next four days. This could be any of the symptoms listed above or even a flu-like feeling.

    2. Test: If you won't do an elimination diet, then schedule your appointment to get a test kit for blood testing.

3. Eliminate: Cut out the foods to which you have had a positive reaction. 100% eliminate these foods from your diet and over time you will notice a sharp decline in your symptoms as well as your seasonal allergies.

4. Heal: You may have created some damage within your gut through long-term exposure to foods that you were sensitive to. This will show up in a variety of symptoms including heartburn, acid reflux, bloating, gas, mucus in the stool, constipation and diarrhea. If you have any of these symptoms it is a good idea to speak with your physician about a protocol specifically for you. In general a good digestive enzyme, probiotics and a nutrient to rebuild the gut lining such as Glycine would be a good general starting point.

Disclaimer: Excelon Health Articles (Excelon Health LLC) do not replace the advice, treatment or diagnosis of your doctor. Information is provided as a resource for general understanding.