How Do Food Allergies Affect Digestion?

Everyday Health: The rates of food allergies continue to rise. What are the most common food allergies, and how do they affect digestion?

Mark Babyatsky, MD (mssm.edu)

Food allergies are estimated to affect 6 to 8 percent of children in the United States and 3 to 4 percent of adults. Many children who demonstrate allergy to milk protein outgrow them. In adults, shellfish, peanuts, tree nuts, fish, and egg are the most common. Of note, those with peanut and tree nut allergies are unlikely to outgrow them, including the recently increasingly prevalent sesame allergy. Symptoms are usually acute, but can be chronic and include the gamut of allergic responses in the entire body. In the digestive tract, symptoms include nausea, vomiting, abdominal pain, odynophagia (painful swallowing), diarrhea, or any combination of these symptoms.

Kenneth Brown, MD (kennethbrownmd.com)

Many patients feel they are allergic to a food product because they had some sort of reaction after eating. Although adverse food reactions are common, true food allergies are only present in 3 — 4 percent of adults. An allergy is defined by having an adverse immune response to a food protein. One of the most common food allergies is an intolerance to gluten, known as celiac disease. Celiac disease is a common problem, affecting 1 in every 133 people in the United States. It is a lifelong autoimmune disorder in which the body creates a toxic response to the ingestion of any type of gluten. Gluten is the protein found in all forms of wheat, barley, rye, and some oats. This causes damage to the small intestine, which does not allow for absorption of essential nutrients and minerals into the body. Thus, celiac is classified as a disease of an autoimmune reaction to gluten.

More commonly, people have intolerances to foods, rather than allergies. An example of food intolerance is when someone has bloating and diarrhea after consuming lactose. These people have low levels of the enzyme lactase, which prevents the lactose sugar from being broken down.

Lisa Ganjhu, DO (wehealnewyork.org)

Some of the most common food allergies are peanuts, milk, soy, shellfish, fish, nuts, and eggs. Some people can have very severe reactions to those foods if they are allergic. The digestive tract is the first line of contact to food, so it is where allergic reactions originate. The gastrointestinal reaction is to rapidly get rid of or neutralize the irritant or the allergen. Common gastrointestinal reactions are abdominal pain, nausea, vomiting, and diarrhea.

Lisa Pichney, MD (stopcoloncancernow.com)

The eight most common food allergens are milk, wheat, soy, shellfish, fish, peanuts, tree nuts, and eggs. Celiac disease involves an allergy or sensitivity to gluten, which is found in wheat. Patients with celiac disease may malabsorb macronutrients and become ill.

Seth Rosen, MD (gastrohealth.com)

While true allergies to food are often difficult to define, there are a variety of conditions that can cause intolerance of certain foods. Examples of this are lactose intolerance and celiac disease. Lactose intolerance is an inability to properly digest milk and other lactose products such as cheese and ice cream. A patient with lactose intolerance may experience bloating, gas and flatus, and diarrhea after eating foods these foods. There is a specific breath test that can be used to diagnose this condition. Lactose intolerance can be treated fairly easily with enzyme pills (Lactaid) or milk products that have this enzyme added. Even cheese and ice cream can be found with the enzyme included. There also several non — lactose milk product alternatives, such as soy milk or rice milk. Celiac disease — also called gluten sensitivity — occurs when the body develops an abnormal response to the protein gluten which is found commonly in grains. This immune response triggers a reaction in the lining of the small intestine that can cause malabsorption. The treatment for celiac sprue is the avoidance of foods made with barley, rye, oats, or wheat. There are special breads, cookies, cakes, and cereals made without gluten. An increasing frequency with which celiac disease is diagnosed has also created awareness among restaurants so that gluten — free items are commonly found on menus. Bloating, recurrent or chronic diarrhea, anemia, weight loss, and osteoporosis are some of the signs and symptoms that develop from a gluten allergy. If you experience some of these symptoms inform your physician.

Sutha Sachar, MD (susacharmd.com)

Food allergies occur when your immune system identifies a specific food as something foreign or harmful. Your immune system triggers cells to release antibodies known as immunoglobulin E (IgE). This is what triggers histamine release that causes abdominal pain, diarrhea, nausea, or vomiting. The most common allergies include shellfish such as shrimp, lobster, and crab; peanuts; tree nuts, such as walnuts and pecans; fish; and eggs.

Albert Snow, ND (holisticgastroenterology.com)

Food allergies do not affect digestion; digestion affects food allergies. A food allergy is simply a lack of digestion. It is never the food's fault; it only has to do with us not processing it properly. We need to stop playing the "blame game." Our digestive system and our immune system are one and the same. It does not care or distinguish between a food and a germ. When working well it digests both. Dairy and wheat products account for most of the food allergies because they are more complex. Our body's digestion has been "dumbed down" by the universal use of certain medications.

AA Starpoli, MD (starpoli.com)

Gluten allergy, known as sprue of celiac disease, causes an acute inflammatory reaction at the level of the small intestine closer to the stomach proper that leads to swelling and inflammation of the proximal small intestine that prevents the proper absorption of nutrients. There is also soy allergy that causes a similar inflammatory reaction that prevents proper absorption. Lactose intolerance may be considered one as well.

William Chey, MD (med.umich.edu)

National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, defines a food allergy as "an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food." A food allergen is defined as specific components of food or ingredients within food (typically proteins) that are recognized by specific immune cells and elicit specific immune reactions resulting in characteristic symptoms. Food allergies can cause a broad range of problems ranging from mild vague symptoms like an itching sensation in the mouth or throat to severe effects on the respiratory and circulatory systems which can rarely lead to death. The most common food allergies include peanut, tree nuts, fish, shellfish, milk and egg. Though the incidence of food allergies appears to be rising, they are still rare: 4 to 8 percent of children and 1 — 4 percent of adults will have a true food allergy. Most symptoms that occur after eating food are not the result of a true food allergy. So called food intolerances refer to the development of adverse reactions to food. Food intolerances are quite common, reported by 5 to 45 percent of the general population.

Jacqueline Wolf, MD (drjacquelinewolf.com)

Food allergies are present in 3 to 4 percent of adults. Children under the age of 5 have about twice as much food allergy as adults. IgE — mediated food allergy can cause anaphylaxis (trouble breathing, throat and skin swelling, etc.) Peanuts, tree nuts, fish, and shellfish cause more anaphylactic reactions than other foods. In children milk is a common cause of food allergy also. In this condition there can be swelling of the intestinal lining and even lesions like hives in the intestine. The histamine that is released can cause nausea and/or diarrhea.

Celiac disease can be considered a non — IgE immune — mediated allergy. The reaction to the gliaden protein in gluten (a protein in wheat, barley, and rye) causes damage to the small intestine and can result in the malabsorption of nutrients, diarrhea, anemia, and even joint pain and depression. In the United States 1 in 80 to 1 in 140 people have celiac disease and the number is rising. It causes damage to the lining cells of the small intestine so that the nutrients cannot be absorbed normally and there can even be secretion of fluid into the bowel.