Spring 2018 Food Allergy Research Roundup
Spring is almost here, which means it’s time for another edition of our conglomeration of the latest bits of research surrounding food allergies. This past season has been eye opening in the world of food allergies, with discoveries that may pave the way toward prevention and treatment of allergies as well as studies that expound further on scientists’ growing understanding of food allergy topics.
Researchers Discover Receptor that Protects Against Asthma and Allergies
Researchers at Johns Hopkins Bloomberg School of Public Health have recently discovered that a special receptor found on cells that line the sinuses, throat and lungs plays a role in suppressing immune reactions to common triggers of asthma and allergies. The receptor is known as dectin-1 and is able to recognize a protein found in common asthma and allergen triggers such as dust mites, shellfish, cockroaches and other invertebrates.
Scientists in the study, published on February 23, 2018, in Science Immunology, determined that people with asthma or chronic sinusitis are more likely to have impairment in this protective mechanism, which increases their sensitivity. Researchers examined mice that were genetically engineered to lack the dectin-1 receptor and their responses to dust mites. They compared their responses to mice whose airway cells still expressed dectin-1. It was determined that when dectin-1 was blocked with antibodies, the same allergy-promoting effect took place, suggesting that dectin-1 in fact protects against dust mite allergies.
This discovery may be promising not only for individuals with dust mite allergies and other invertebrate-allergic responses but also for people with other airborne and dietary allergens. There is hope that other undiscovered receptors are able to be found that suppress allergic responses, which may shed light on new ways to treat such conditions.
Food Allergy and Genetics, Gender and Ethnicity
An Australian SchoolNuts study has found a link between genetics, gender, ethnicity and the development of food allergy. The study was performed by sending a survey to 4,991 10- to 14-year old adolescents and their caretakers. The children were also given an oral food challenge if allergy was suspected from the questionnaire as well as a clinical evaluation.
According to the study, having early-onset eczema, being of Asian descent and being male with a history of allergic disease increase the risk of the development of adolescent food allergy. The study also determined that the more allergic family members a person has, the higher that individual’s risk of the development of allergies.
This isn’t the only study suggesting that children of Asian descent were more likely to develop allergies. A previous study by the same group showed that children were three times more likely to develop egg and peanut allergy by the age of one if they were born of parents from in East Asia in comparison to children of parents born in Australia.
Association Between Early Childhood Gut Microbiome and Egg Allergy
Results from a new study propose that gut microbiota in early life may play a role in the development of egg allergy. In this study, 141 egg-allergic children were examined against controls from the Consortium of Food Allergy Research study. Children were enrolled between the ages of 3 and 16 months. At enrollment, fecal samples were taken as well as egg-specific IgE measurements and skin prick tests along with a clinical evaluation. Gut microbiome was also profiled and analyses were run for the primary outcome of egg allergy. According to study results, greater gut microbiome diversity was associated with egg sensitization. There was no association between gut microbiota and the resolution of egg allergy by eight years among egg-allergic children in the study. This suggests that the analysis of early life microbiota in children who are egg sensitive or allergic may be beneficial for determining therapeutic or preventive intervention.
Children with Cow’s Milk Allergy are Typically Smaller Than Nut-Allergic Peers
During the American Academy of Allergy, Asthma & Immunology/World Allergy Organization Joint Conference, a chart review was presented that suggested children with persistent cow’s milk allergies may continue to be shorter and lighter throughout childhood in comparison to children who are allergic to tree nuts or peanuts.
Previous research has showed that children with food allergies are at risk for being shorter in height and lower in weight than children without food allergies, and this study further proves that children with cow’s milk allergy are at an even greater risk. According to the lead researcher, this may be in part due to the fact that cow’s milk is found in many food items, significantly narrowing food options for growing children who are allergic to dairy.
During the study, 191 children were assessed. To be part of the study, the children needed to have at least one clinical visit between the times they were 2 to 4, 5 to 8, and 9 to 12 years old. The research team recorded height, weight and co-morbid conditions including eczema, seasonal allergies, asthma and use of inhaled corticosteroids. Mean differences were calculated in height, body mass index z-scores and weight. Comparisons were made between values among other kids of the same age and gender and those with food allergies.
According to research results, children in the 5-to-8 year-old group as well as the 9-to-12 year-old group who were allergic to cow’s milk had lower mean height and weight compared to children who were allergic to peanuts and tree nuts. Future research will be needed to determine whether older children will begin to bridge the gap in differences or if growth differences will continue.