Most of the processed and packaged foods you find on your grocery store shelves are laden with additives, preservatives, colorings, flavorings and a number of other chemicals designed to make the product look and taste good. However, each of these additional chemicals increases your risk you’ll have an adverse reaction.

Food allergies are the fifth leading cause of chronic illness in the U.S.,1 and the number of people who suffer from them is on the rise. In the decade between 1997 and 2007, the incidence of food allergies rose by nearly 18 percent in children under 18.2 Today, nearly 1 in every 13 children has some type of food allergy.3

Some of the more common foods that spark an allergic reaction in children are nuts, soy, wheat, shellfish and milk. Why those particular foods are the leading triggers is still not fully understood. Dr. Kari Nadeau, director for the Stanford Alliance for Food Allergy Research, points out there is no one protein similar between the foods, and that 30 percent of people who do have food allergies often are allergic to more than one food in that group.4

Scientists have found that allergies may run in families, meaning there may be a genetic factor, as well as environmental factors in the development of food allergies. However, at this point, there is no complete answer as to why some people develop a highly sensitive reaction to some foods and others don’t. In the past, many of the cases of food allergies began in childhood, but today, it is not uncommon for those over 18 to develop an allergic reaction to foods, even those they have been eating their whole life.

Adult Onset Food Allergies Are Not Uncommon

Preliminary data from a national study shows that nearly 52 percent of Americans who have food allergies developed them after the age of 18.5 These same results showed that shellfish is the most common food allergy, followed by peanuts and then tree nuts, such as walnutspecans and cashews. Interestingly, when children are allergic to eggs, milk or wheat products, they may grow out of the reaction as they age. However, adults who develop a food allergy usually continue to suffer for the remainder of their life.

Dr. Ruchi Gupta, a food allergy researcher at Ann and Robert H. Lurie Children’s Hospital, led this national study. She had found that in medical meetings around the world there appeared to be a higher number of adults reporting food allergies. However, as this was anecdotal evidence, Gupta and her team set out to quantify the information.6 The researchers surveyed over 40,000 adults from a national sample and found the foods that triggered allergic reactions in adults were the same as those affecting children.

Once the data was compiled, Gupta expressed interest in “why” adults develop food allergies. While gathering data from the sample, researchers asked the participants why they thought they had developed food allergies as an adult. The answers ranged from changing hormonal levels, moving to another area of the country or a viral illness.7 Gupta hopes to answer questions about why children maintain allergies through adulthood, and how adults are developing new ones, as these answers may have a significant public health impact.

The results of this study confirmed results of another study by FAIR Health that found a 377 percent jump in severe food reactions in the past decade.8 FAIR Health9 is a nonprofit, national repository of insurance claims data. The group looked through 24 billion insurance claims filed by 150 million people for diagnoses where anaphylaxis was caused by food reactions.