Food allergies: Understanding the causes and magnitude of the problem

By Dr. Ananya Mandal, MDJun 1 2017

Did you know 3.6% of the population has a documented food allergy and the most vulnerable population are females and Asians? This is what researchers have found trying to delve deeper into understanding food allergies.

Since the beginning of 20th Century the cases of food allergies are on the rise. These were first described by French scientists, Charles Richet and Paul Portier, who described anaphylactic reaction to food allergy. They were awarded the Nobel in 1913 for their breakthrough but the underlying cause of this phenomenon was still poorly understood.

Now around 15 million Americans and 17 million Europeans suffer from food allergies with many of them being children. Peanut allergy alone accounts for around 25% of all cases. Now around 2% of all American children are allergic to peanuts. This is four times the number in 1997. Less than 100 cases a year of fatalities still occur due to food allergies.

Image Credit: Albina Glisic / Shutterstock

The latest study comes from researchers from Brigham and Women's Hospital. They painstakingly looked at medical records of more than 2.7 million patients. Of these they noted that there were more than 97,000 individuals that suffered from documented food allergy or intolerance. They went on to share their findings with the scientific world in the Journal of Allergy and Clinical Immunology.

The focus on food allergies comes from anecdotal sources that these seem to be much too common these days. Over the last decade there have been millions of hospitalizations due to food allergy related accidents. Some of these have been fatal. Most of these studies earlier have looked at telephone surveys of large populations say researchers. So this was a consolidation of earlier findings of researchers on food allergies.

The team thus found that 3.6% of the population had documented and known food allergies. One of the commonest food allergens was not to peanuts as widely thought but shellfish. Females and Asians were the ones who were most affected by documented food allergies said researchers after looking at this vast population.

The team of researchers looking at these findings included a medical student, Warren Acker, an allergist, Kimberly Blumenthal and patient safety experts. They delved into food and allergy intolerance data that came from Partners HealthCare between 2000 and 2013. In addition data from several community and specialty hospitals as well as community health centers were also collected.

The major accused foods, the extent and severity of reactions to the allergens, date/time of the reaction and other data were recorded. The research team were broad in their terminology using the term “food allergies and intolerances” to include all adverse reactions to food as well as intolerances or pseudoallergies. The types of reactions included were rash, hives, shortness of breath, itching, swelling, wheezing etc.

They noted that over 13,000 patients had an allergy or intolerance to peanuts. Nearly 56.5 percent of these developed near fatal reactions to peanuts such as anaphylaxis and hives. They used radioallergosorbent test (RAST) or ImmunoCAP test for all patients who had peanut allergy to pinpoint the allergy.