I get a stomachache whenever I drink milk. Does that mean I’m allergic to it and should completely avoid it?
The short answer: Not necessarily
The explanation: While you may have a physical reaction to a food, it may be due to an intolerance or sensitivity to that food, or something in it, rather than an allergy. What’s the difference and why does it matter?
- A food allergy is an abnormal immune reaction to a substance, with the body reacting as though a normally harmless substance is dangerous and releasing immunoglobulin E (IgE) antibodies to fight against it. When stimulated by the substance, the IgE antibodies release histamines causing inflammation. These can, in turn, cause allergic reactions from respiratory issues to hives to low blood pressure and anaphylactic shock – which can lead to death if not immediately countered (e.g., with an epinephrine injection/EpiPen.) Because even a small amount of ingestion of, or even contact with, an allergen can cause a serious reaction in an allergic person, complete avoidance is required. Thus, most countries have food allergen labeling requirements, with the U.S. requiring nine major allergens to be declared on food labels (peanut, tree nut, milk, egg, wheat, soy, fish, shellfish, sesame).
- Although a food sensitivity can cause the body to emit IgE antibodies against the substance, there will be no abnormal, immune-related reaction to exposure. Rather it is more of the intensification of a normal side effect of the substance. One of the most common of these is the sensitivity to gluten. Symptoms can be serious, particularly with repeated exposure, but it can be difficult to determine the source of a sensitivity.
- A food intolerance causes a chemical, non-immune reaction to a substance, generally affecting the digestive system caused by a lack of an enzyme or chemical needed to break down the substance. While physical symptoms result, such as bloating, gas, and diarrhea from lactose intolerance, the symptoms are not immune-related, so it is not considered an allergy. The effects can be very uncomfortable, but they are not as serious or life-threatening as an allergy.
When you have a reaction to a food, it is important to know if it is an allergy, sensitivity, or intolerance, so that proper care can be taken with your food choices in the future.
