Current estimates from various countries suggest that up to 5%-8% of children and 2%-19% of adults have food allergies. Substantial proportions are allergic to cow’s milk, eggs, seafood, or peanuts and these are just a few of the many foods we eat.
If you are not impressed by these figures, ask yourself, are you recently seeing more patients with food allergy than you did 5 or 10 years ago? I contend, yes, you are.
And the literature substantiates that. For example, studies in several countries have documented increases in certain food allergies. A phone survey found the prevalence of allergy to peanuts and tree nuts in the general US population doubled between 1997 and 2002, from 0.6% to 1.2%.
Similarly, it was recently reported that the reported prevalence of food or digestive allergies among US children increased by 18% between 1997 and 2007 (Center for Disease Control and Prevention, National Center for Health Statistics Data Brief, No. 10, October 2008)., Moreover, the annual number of hospital discharges with any diagnosis related to food allergy in children rose by 365% between 1998 and 2006.
There are at least three plausible main reasons for this increase.
First, allergies and asthma in general have been increasing. Rates of atopic dermatitis, anaphylaxis, and eosinophilic gastrointestinal disorders are all higher than they have been in the past. Foods are strongly implicated in these diseases.
Second, the causes of food allergy are on the rise. Today, people eat more fod and a greater variety, and some of these foods cross-react with others or with noningested allergies (latex, cockroach, mite, and pollen). Commercial foods now include numerous nutrient and nonnutrient allergenic ingredients. And food proteins have been increasingly incorporated into medical diagnostics and therapeutics, particularly in dermatology.
Third, contributory factors that predispose individuals to food allergy are ever more common. Fortunately, atopic individuals have high survivorship today, but this also leads to the perpetuation and spread of the predisposing genetic traits. We are living in cleaner environments, which have implications in terms of the hygiene hypothesis. There is an obesity pandemic, and leptin has been implicated in allergic sensitization. Additional contributory factors that are growing more common include cesarean and use of antacids, and possibly use of infant multivitamins.
The evidence for a trend of increase in food allergy is compelling.