Most common food allergies include:
- Tree nuts
Proteins in these foods trigger an abnormal immune response in persons allergic to the food. In comparison, food intolerances are due to the inability of the body to digest or metabolize a food component. For example, lactose intolerance is caused by a deficiency of the enzyme lactase that breaks down the sugar lactose in milk and milk products.
Because food allergies and food intolerances can cause some of the same symptoms (e.g., stomach cramps, vomiting and diarrhea), they're often mistaken for one another. Those who think they may have a food allergy or food intolerance should be medically evaluated to avoid unnecessarily eliminating foods from their diet. Most persons who have a food allergy need to totally eliminate the offending food and ingredients that contain the food's protein from their diet. However, for some food intolerances, like lactose intolerance, smaller portions (e.g., 4 ounces of milk) or a modified version of the offending food (e.g., lactose-reduced or lactose-free milk, yogurt or cheese) may be well tolerated.