Q: Does the dry roasting cooking process used to make peanut butter and many peanut snacks have anything to do with how allergenic peanuts have become for so many?
Dr. Sicherer: There is a theory that the process of roasting makes changes in peanut proteins that result in a more allergenic form. It’s important to realize the theory is somewhat circumstantial. For example, the per capita consumption of peanut in China is similar to that in the United States, and yet peanut allergy is relatively uncommon in most areas of China.
In the United States, most peanut is roasted and in China it is primarily consumed boiled or fried. There are also laboratory studies evaluating immune responses against boiled versus roasted peanut, suggesting the roasted version is more allergenic.
However there are flaws in the theory. Peanut allergy in the U.S. does seem to have increased over a period of time when roasted forms were the primary forms consumed. In a study evaluating the prevalence of peanut allergy among Jews, the rate was one-tenth among those in Israel versus those in the United Kingdom, but the forms eaten in both countries are primarily roasted.
Therefore, alternative theories about increase in food allergy in general, and peanut allergy in particular, continue to be explored.
As a practical point, if an individual has a peanut allergy and has had a reaction to roasted peanut, it should NOT be assumed that boiled peanut would be tolerated.
Dr. Scott Sicherer is Chief of the Division of Allergy and Immunology of the Jaffe Food Allergy Institute at the Icahn School of Medicine at Mount Sinai in New York. Together with Dr. Hemant Sharma, Associate Chief of the Division of Allergy and Immunology at Children’s National Medical Center in Washington, he writes “The Food Allergy Experts” column in the American Edition of Allergic Living magazine. Questions submitted below will be considered for answer in the magazine.