Crave Health intern Alyssa Rieser is going to straighten out the confusion on these differences and Ashley will explain some options for next steps if you may suspect a food sensitivity or intolerance.
Adverse reactions to food are increasingly common - from peanut allergies to celiac disease to lactose intolerance. The National Institute of Allergy and Infectious Diseases reports that approximately 5 percent of children and 4 percent of adults in the United States are affected by food allergies. Far more people have a food intolerance, but the two conditions are often confused because they have similar symptoms.
Food Allergy
A true food allergy is caused by a hyperactive response by the immune system to a normally harmless component of a food, most often a protein. The immune system reacts to the protein by producing immunoglobulin IgE antibodies which induce a range of possible symptoms, affecting numerous organs:
Skin: hives, itching, eczema, dermatitis, and swelling of the lips and face.
Gastrointestinal: nausea, vomiting, diarrhea, cramping, and a tingling or burning sensation in the lips and mouth.
Respiratory: nasal congestion, runny nose, sneezing, throat swelling, wheezing, and difficulty breathing.
The reaction is usually immediate and happens even when consuming just a small amount of the offending food. Responses range from mild to severe. Rarely, a person may go into anaphylaxis, a life-threatening allergic response that causes the airways to close and blood pressure to drop dangerously low. There are 160 foods known to cause an allergic response. Of those, eight account for 90 percent of all allergic reactions: milk, egg, peanuts, tree nuts (walnuts, cashews), fish (pollock, salmon, cod, tuna, snapper, eel, and tilapia), shellfish, soy, and wheat. Because of the risk of anaphylaxis, even in those who have had mild reactions previously, individuals with food allergies need to completely avoid the triggering food.
If you suspect you have a food allergy, it is best to see an allergist for testing and diagnosis. The three most common tests are the skin prick test, blood test (RAST), and food challenges. The skin prick and blood tests detect IgE antibodies that form in the blood when an allergenic food is consumed. Neither test detects non-IgE allergens however. The advantage of the skin prick test is that the result is available in minutes, however the RAST test can detect multiple food allergens at once. In a food challenge test, the allergen is administered to the patient in the form of a pill so it may be directly ingested. The person is then observed for signs and symptoms. The disadvantage of this test is that it must be done in a hospital under professional supervision because of the risk of anaphylaxis.
Food Intolerance
In contrast to an allergy, a food intolerance does not involve an immune system reaction. It is more common and generally less serious. Symptoms, while more often limited to digestive distress, may include any of the following: nausea, stomach pain, gas, cramps, bloating, vomiting, heartburn, diarrhea, headaches, irritability, and nervousness. The response time is slower, anywhere from 30 minutes to 48 hours, making this condition more difficult to diagnose than a food allergy.
The most common food intolerances are to:
- wheat and other gluten-containing grains
- sugar found in fruits and honey (fructose)
- cow’s milk and dairy products
- corn
While food allergies are caused by the IgE-mediated immune response to a normally harmless protein, food intolerances have a wide variety of causes including:
- Absence of a digestive enzyme. For example, lactose intolerance is due to the lack of the enzyme called lactase which helps us to digest the sugar lactose found in milk products.
- Sensitivity to food additives, such as sulfites used to preserve dried fruit, canned goods, and wine.
- Sensitivity to chemicals naturally occurring in food such as salicylates, nitrates, and amines. Salicylate-containing foods include apples, citrus fruits, strawberries, tomatoes, and wine. Amine-containing foods include chocolate, cheese, bananas, avocado, tomato, beer and wine.
- Celiac disease is a permanent intolerance to gluten (a protein found in wheat, spelt, kamut, barley, and rye). This condition is often hereditary, and has an autoimmune component. As long as gluten is in the susceptible person’s diet, the body attacks its own tissues. This results in inflammation and atrophy of the digestive tract, eventually leading to malabsorption and serious nutritional deficiencies.
Tests for a food intolerance include hydrogen breath testing for lactose intolerance and fructose malabsorption, elimination diets, and ELISA testing (a blood test) for IgG-mediated immune responses to specific foods. Elimination diets are a popular choice among individuals who experience non-specific digestive distress, headaches, and other symptoms. Under the care of a registered dietitian or other qualified health-care professional, the patient completely removes all foods that may be causing an adverse reaction (this varies, but at least includes the removal of soy, eggs, dairy, and gluten). After a predetermined period of time, the patient slowly adds the foods back into their diet, one at a time, and watches for adverse reactions.
With either condition, it is helpful to talk to a registered dietitian about diet modifications. An RD can help you identify which foods are safe to eat, ensure that you’re getting all the vitamins and minerals you need, teach you how to identify hidden allergens by reading ingredients labels, and support you in making any necessary lifestyle changes to maintain health and well-being.
If you suspect that you may have a food sensitivity, you can begin an elimination or challenge diet with an RD, or you can get an IgG-mediated blood test. The unfortunate thing is that insurance will not cover IgG-mediated tests since its not considered necessary. There are lots of great companies that offer these tests, our favorites here at Crave Health are the ALCAT test and the 90 Food Metamatrix Test. All IgG tests cost around $300 and some more comprehensive tests can be more expensive. Contact Ashley for more info, the best test for you, and pricing options.
-Alyssa & Ashley
