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 Center for Disease Control (CDC) in 2007, approximately 3 million children under age 18 (3.9% of the population or almost 4 out of every 100) were reported to have a food or digestive allergy in the previous 12 months. From 1997 to 2007, the prevalence of reported food allergy increase 18% among children under age 18. Children with food allergy are two to four times more likely to have other related conditions such as asthma and other allergies, compared with children without food allergies.

Further statistics from the CDC show that in 2007, 29% of children with food allergy also had reported asthma compared with 12% of children without food allergy. And approximately 27% of children with food allergy had reported eczema or skin allergy, compared with 8% of children without food allergy.

The Food Allergy Initiative (FAI) funded a study by Dr. Ruchi Gupta of Northwestern University Feinberg School of Medicine, Chicago, IL called “UNDERSTANDING THE PREVALENCE OF CHILDHOOD FOOD ALLERGY IN THE UNITED STATES 2008-2010″ in which she completed a national survey of more than 38,000 families. Dr. Gupta and her colleagues found that 8% (5.9 million) of U.S. children had one or more food allergies.  According to this study, approximately 1 in every 13 children in the U.S. has a food allergy—twice as many as the CDC estimate of 1 in 25.  Nearly 39% (2.3 million) of these children have a severe, or life-threatening, food allergy.  More than 30% (1.7 million) of these children are allergic to more than one food.  The data also shows that food allergies do not discriminate—food allergies affect U.S. children in all geographic regions and across all ethnicities.

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 and colleges 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%.

Research is ongoing to determine the cause for this huge increase of food allergies. There are some promising studies regarding Chinese herbs and heat-killed bacteria immunotherapy, however no cure has been found yet! For more information about curing food allergies, please click here.