Prevalence of Food Allergies in today’s world

The prevalence of food allergies varies by country and by food. Many studies have been completed over the past few years in an attempt to determine how many children, in particular, have food allergies. According to the Food Allergy & Anaphylaxis Network (FAAN), 1 in 25 children under the age of 18 have a food allergy, the ratio jumps to 1 in 17 children under the age of 3 that have a food allergy.

For those of us in our 40’s, we’d be hard pressed to remember any child in our elementary school who had food allergies. I remember the occasional child having asthma, but food allergies were unheard of 30+ years ago.

Today, you’d be hard pressed to find someone who didn’t know a child who suffers from food allergies. Almost every preschool has dealt with a food allergic child! And as children age, high schools are becoming more aware also.

The Asthma & Allergy Foundation of America (AAFA) states that asthma and allergies affect 1 out of 4 Americans, or 60 million people. Further, they report that allergies have a genetic component. If only one parent has allergies of any type, chances are 1 in 3 that each child will have an allergy. If both parents have allergies, the chances increase to 7 in 10 that their children will have allergies. Dr. Scott Sicherer, in his book, “The Complete Peanut Allergy Handbook” also states that “there is a 7 percent risk, or about ten times higher risk than normal, for developing a peanut allergy if one sibling has a peanut allergy.”

Research reported in the April 1999 JACI (Journal of Allergy & Clinical Immunology) estimated that 1% of the population, or close to 3 million Americans, is allergic to peanuts or tree nuts. The JACI is the peer-reviewed scientific journal of the American Academy of Allergy, Asthma and Immunology (AAAAI). The prevalence of peanut allergies has doubled in the 5 years from 1997 to 2002 according to research reported in the December 2003 JACI, and researchers don’t really know why.

There is the thought that roasting peanuts, as we do in the USA makes them more highly allergenic versus boiling them as China does. There’s also the possibility that pregnant and nursing women who eat peanuts are passing the proteins on to their infants which increases the likelihood of the child developing a peanut allergy. Lastly, there is the supposition that our too clean houses don’t challenge our immune systems to fight off parasites, and instead they turn on themselves viewing a food protein as the enemy.

According to the Allergy & Asthma Foundation of America, milk is one of the most common food allergens in children. Studies in several countries around the world show a prevalence of milk allergy in children in the first year of life of around 2% to 5%. 

Soy-based formulas were introduced in infant nutrition 80 years ago, when their use was recommended for the treatment of summer diarrhea. Seventy years ago, the use of soy-based formulas was extended to the treatment of cow milk intolerance. In the 1970s, use of soy-based formulas became common, and in the 1970s and 1980s, US consumption was around 25% of that of cow milk–based formulas.

Stefano Guandalini, MD Director, University of Chicago Celiac Disease Program, Section Chief of Gastroenterology, Hepatology and Nutrition performed research on soy allergy and found:

In the US: In a national survey of pediatric allergists, the prevalence rate of soy protein allergy was reported to be 1.1%, compared to the 3.4% prevalence rate of cow milk protein allergy. 

Internationally: In a prospective study of healthy infants fed soy-based formula, allergic responses to soy were documented in 0.5% of infants. 

In a group of 243 children who were born of atopic parents (parents with allergy issues) and who received soy formula for the first 6 months of life to prevent cow milk allergy, 14 (6%) of the children had positive skin test prick reactions to soy. 

In a group of 93 children with documented IgE-associated cow milk allergy who received soy formula, 14% developed soy allergy. 

Doctors Scott Sicherer and Hugh Sampson of the Jaffe Food Allergy Institute, along with the Food Allergy & Anaphylaxis Network determined the prevalence of seafood (fish and shellfish) allergy in the US to be 2.3% of the general population or 6.6 million Americans, with the prevalence more common in adults than children. 

There haven’t been recent studies as to the prevalence of wheat allergy in the USA. However Celiac Disease, an intolerance to wheat, affects 1 in 133 Americans according to the University of Maryland Center for Celiac Research.

Allergies can be passed from parent to child. Children may inherit the tendency to develop allergies if either parent or any family member suffers from eczema, asthma, or food allergies. The specific allergy is not inherited from the parents, merely the tendency to be allergic. If neither parent is allergic research suggests that there is still a 5-15% chance that the child will develop allergies. For a child with allergic parents, this increases to 25%. If both parents are allergic there is a 50-60% chance of developing allergies. When both parents have the same allergic disease the risk increases to 80%.

According to the February-March 2005 edition of Food Allergy News, a publication of FAAN (Food Allergy & Anaphylaxis Network), 11.4 million Americans, or 4% of the population have a food allergy. Research is ongoing to determine the cause for this huge increase over the past 10 years, when scientists believed that less than 1% of the population was affected by a food allergy. There are some promising studies regarding Chinese herbs and heat-killed bacteria immunotherapy, however no cure has been found yet!