Research has determined that Australian-born children with Asian mothers have higher rates of nut allergy than Asian-born children who migrate to Australia.
The study suggests that the Asian environment is more protective of food allergies than the Australian environment, possibly due to variations in diet, bacteria or UV exposure, according Murdoch Childrens Research Institute researcher Professor Katie Allen.
The study, conducted by Murdoch Childrens Research Institute and University of Melbourne, analyzed data from 57,000 five year-olds collected during 2010 School Entrant Health Questionnaire. 2892 parents reported a food allergy (5%) and 1761 (3.1%) reported a nut allergy. While Australian-born children of Asian descent were more likely to have nut allergy than non-Asian children, children born in Asia who migrated to Australia were at decreased risk. Professor Allen said that migration from Asia after the early infant period appears to be a protective factor against the development of nut allergy.
Said Professor Allen:
“We know there are rising rates of migration from East Asia to Australia. Our finding that migration from Asia to Australia after birth can protect against early onset allergic disease such as food allergy provides a potent clue for us to follow when trying to understand why food allergy is on the rise.”
Professor Allen said the results suggest that removing children from the Asian environment, or conversely exposing them to environmental risk factors in our Western environment – such as changes in diet, microbial and UV exposure – uncovers a genetically-determined risk of food allergy in children of Asian descent.
Professor Allen echoed this sentiment for children raised in rural areas.
“The overall presence of nut allergy in metropolitan Melbourne was 3.4 per cent, compared with 2.38 per cent in non-metropolitan areas. While the question still remains as to why allergy rates are on the rise, the urban-rural difference could be down to the hygiene hypothesis- which raises the possibility that our urban environment with less diverse microbial exposure may contribute to the rise in allergies,” said Professor Allen.
“It strongly suggests that early life environmental factors linked to the modern lifestyle play a key role in allergy development. Understanding these factors better will provide opportunities to intervene to prevent food allergy in the future.”