Food Allergies and Sensitivities
- Allergies, Food
Principal Proposed Natural Treatments
- Elimination Diet
- Hypoallergenic Infant Formula
Other Proposed Natural Treatments
A food allergy is defined as an abnormal immune reaction caused by the ingestion of a food or food additive. The most dramatic form of food allergy reaction occurs within minutes, usually in response to certain foods such as shellfish, peanuts, or strawberries. The effects are similar to those of a bee sting allergy, involving hives, itching, swelling in the throat, and difficulty breathing; this immediate type of allergic reaction can be life-threatening. Other food allergy reactions are more delayed, causing relatively subtle symptoms over days or weeks. 1 These include gastrointestinal problems (constipation, diarrhea, gas, cramping, and bloating), rashes, and headaches. However, because such delayed reactions are relatively vague and can have other causes, it has remained a controversial subject in medicine. Some food allergy-like reactions do not actually involve the immune system. These are termed food sensitivities (or food intolerance). In most cases, the cause of such sensitivities is unknown. Delayed-type food allergies and sensitivities might play a role in many diseases, including asthma , attention deficit disorder , rheumatoid arthritis , vaginal yeast infections , canker sores , colic , ear infections , eczema , irritable bowel syndrome , migraine headaches , psoriasis , chronic sinus infections, ulcerative colitis , Crohn's disease , and celiac disease. 2-9,64, 68 However, not all experts agree; practitioners of natural medicine tend to be more enthusiastic about the food allergy theory of disease than conventional practitioners. Conventional treatment for immediate-type food allergy reactions includes desensitization (allergy shots), emergency epinephrine (adrenaline) kits for self-injection, and the antihistamine diphenhydramine (Benadryl). Delayed-type food allergies are much more difficult to identify and treat. Although skin and blood tests are sometimes used, their reliability is questionable. 10-16,65,66 A particular blood test called ALCAT has shown some promise, but much more study is necessary to establish its accuracy. 17 The double-blind food challenge is the only truly reliable way to identify delayed-type food allergies. This method uses some means of disguising the possibly allergenic food, usually by mixing it with other, nonallergenic foods. Individuals are randomly given either the possibly allergenic food or placebo on a number of occasions separated by 1 or more days. Neither the physician nor the participant knows which is real possibly allergenic food and which is not. Evaluation of the response can then determine whether an allergic response is really present or not. Studies suggest that perhaps only one-third of people who believe they are allergic to a given food actually experience an allergic reaction when they are given it in a double-blind fashion; in addition, reactions are often milder than individuals believe. 18,19Although it is the most accurate way of determining food allergies, the double-blind food challenge is still mostly used in research. The elimination diet with food challenges (described below) is the most common technique in use. Another conventional approach for delayed-type food allergies is oral cromolyn (a drug sometimes used in an inhaled form for treating asthma and other allergic illnesses). 20 A double-blind, placebo-controlled study of 14 children with milk and other food allergies found that cromolyn was effective in preventing allergic reactions in 11 of 13 cases, whereas placebo was effective in only 3 of 9 cases. 21 In another study, 32 individuals were given cromolyn one half hour before meals and at bedtime. 22 If their food allergy symptoms were prevented, the participants were entered into a double-blind, placebo-controlled crossover study using cromoglycate. Of the 31 people who completed the study, 24 experienced relief of gastrointestinal symptoms when taking cromolyn as compared to 2 when taking placebo. In addition, systemic allergic reactions were also blocked with the cromolyn. Unfortunately, the drug also had many side effects.