If the population of one Minnesota county is any indication, rates of peanut allergies has been on the rise over the last decade, according to a new study.
The new research, published in the Journal of Allergy and Clinical Immunology, showed that rates of new peanut allergy cases in Olmsted County tripled between 1999 and 2007 -- from 2.05 cases out of 10,000 children, to 6.88 cases out of 10,000 children.
The findings are based on more than 500 people with potential diagnoses of peanut allergy, which yielded 170 actual new cases of lab-confirmed peanut allergy. Overall, the percentage of people in Olmsted County with peanut allergy in 2007 was 0.65 percent.
The researchers noted that other estimates of peanut allergy rates may differ because of how peanut allergy is defined -- whether it's just a self-reported allergy, or if it's an actual lab-confirmed allergy. This new study only included responses from people whose peanut allergy had been lab-confirmed, Reuters reported.
But "no matter how we're defining peanut allergy, we're seeing this consistent increase," study researcher Maria Rinaldi, of the University of Minnesota, told Reuters.
In 2010, another study also suggested the tripling of peanut allergy cases over the last 10 years. That study, conducted by researchers at the Jaffe Food Allergy Institute at Mount Sinai School of Medicine, included 13,534 people, whose rates of food allergy were compared with those in 1997 and 2002, LiveScience reported.
The American Academy of Allergy, Asthma & Immunology reports that peanut allergies are the most common among children, with milk allergies being second most common and shellfish alleges being third most common.
However, despite the prevalence of nut allergies, people who actually have the allergies may not always be able to identify the nuts they are allergic to, according to a study in the journal Annals of Allergy, Asthma & Immunology. In that study, only about half of people with nut allergies were able to identify the nuts they are allergic to when shown 19 samples of nuts -- including pine nuts, pistachios, cashews, peanuts and walnuts -- that were presented in a variety of different ways.