If you got through childhood without suffering any allergies, particularly food allergies, you may be surprised to learn that you can still develop them. In fact, adults can grow into them while children can grow out of them, says Manish Ramesh, M.B.B.S., Ph.D., an associate professor in the department of medicine (allergy and immunology), and clinical director of the allergy and immunology program at the new Montefiore Einstein Advanced Care (MEAC), where, among other things, he runs the Food Allergy Center. He leads an additional two Food Allergy Centers serving patients in the Bronx and Westchester where some 1,000 patients sought care during the last year.

Manish Ramesh, M.B.B.S., Ph.D.Faculty ProfileResearch Profile

Adults of a certain age may not recall any childhood friends or classmates having food allergies, let alone a potentially life-threatening one to peanuts, which is so common now. Why is that?

“It’s really in the last two decades that we have seen a substantial uptick in food allergies,” says Dr. Ramesh. Indeed – food allergies affect some 32 million Americans (approximately 10.8% of adults and 7.6% of children). A multitude of potential risk factors have been implicated, including our move away from agrarian societies, changes in milieu, changes in food habits, reduced exposures to parasites, changes in our microbial flora and rate of childhood eczema.

Any food can elicit an allergic reaction but there are some foods that are at the top of the list, including milk, soy, eggs, wheat, peanuts, tree nuts and shellfish. Milk and eggs are the most common allergies in infants. Peanuts and tree nuts dominate as food allergies in school age children. The good news is that about 85% of children with milk or egg allergies will grow out of them. However, that is not the case with peanuts; a childhood allergy to peanuts is life-long.

While shellfish is the most common in new onset anaphylactic food allergy in adults, allergic reactions to sesame (seeds, oil, tahini) is on the rise for reasons that are not well understood. The face of food allergies 10 years from now might be quite different due to a push for early introduction of foods such as peanuts in elevated risk children.

There are other types of food allergies, such as food protein-induced enterocolitis syndrome (FPIES) that can occur in infancy, which causes extreme vomiting and diarrhea. The list of common trigger foods is different from anaphylactic food allergies and includes foods such as ice, milk, soy and bananas. Most children outgrow FPIES by age 3 or 4. Adults can develop FPIES too, but it is triggered by a completely distinct set of foods – again the dreaded shellfish is at the top of the list. Allergists suspect this might be underdiagnosed in adults because they may not recognize it as an allergic reaction.

“That’s what makes this specialty so interesting. While food allergies affect people of all ages, they affect all ages a little differently,” says Ramesh. “Unlike many other centers that focus on pediatric food allergies only, we see the gamut of food allergies across all ages.

“We are at an exciting phase in the study and treatment of food allergies because we not only have more options for treating them but also options for preventing them.”

What Causes Food Allergic Reactions?

In people who have allergies, immune cells called B-cells produce an abnormal immune response by making allergen-specific antibodies, called immunoglobulin E (IgE). These antibodies coat the surface of mast cells, which are “ready to go” immune cells that are itching for a fight. When clinicians test for allergies, they measure levels of IgE in the blood. When a person eats a food that they are allergic to, the allergen sticks to the IgE antibodies on mast cells and in doing so triggers them to release many immunoactive substances instantaneously. These substances make blood vessels in the skin leak fluid and cause hives. They narrow the airways, affect circulation and lead to all the symptoms seen with an allergic reaction.

Is it a Food Allergy or Food Sensitivity? What’s the Difference?

Food allergies are different from food sensitivities such as lactose intolerance, which is due to an enzyme deficiency that causes people to be unable to digest the lactose sugar in milk. Similar problems can occur with natural occurring sugars called fermentable oligosaccharides, disaccharides, monosaccharides and polyols. In celiac disease, an autoimmune response develops in people on a wheat containing diet.

Interest in gluten-free diets by companies have been a boon for celiac disease. However, the vast majority of people who avoid gluten-containing foods don’t have celiac disease. They may have other gastrointestinal symptoms or eliminate gluten from their diets as a life choice. A word of caution for those embarking on a gluten-free diet. Many replacement foods can be higher in calories or have refined sugars that cause other kinds of health issues. Says Dr. Ramesh, “I tell people that there are a couple of billion people on the planet who traditionally and primarily eat rice or other naturally gluten-free foods. Over generations they have maintained healthy balanced diets. My advice is that you should avoid foods that make you feel sick or uncomfortable, but make sure that you eat a balanced diet consisting of healthy foods.”

While the scientific jury is still out, the development of food allergies has a strong correlation with the food and environment we grow up in. Studies in identical twins growing in disparate environments and communities transitioning to urbanized lifestyles all indicate that a combination of factors intrinsic to modern westernized societies drive food allergies. Interestingly within one generation, immigrants to westernized societies acquire the same food allergy risk as native counterparts.

So, do you have a food allergy or sensitivity? Best to consult a specialist to find out for sure.

To schedule an appointment at MEAC, call 914-457-4130. To schedule appointments in the Bronx or Scarsdale, call 866-633-8255