Scientists gathered in Melbourne, Australia for the International Congress of Immunology. The focus of the conference was shifting advice on introducing allergens such as peanuts to high-risk children, but a topic of discussion was Melbourne’s localized high rate of food allergies compared to the rest of the developed world. An amalgam of theories attempt to explain this prevalence, but the answer may be a combination of them.
Australia is often called the “food allergy capital of the world” and the city of Melbourne has allergy rates even higher than Australia’s already high national average.
The reasons for this and for the general rise in food allergies globally are likely many, with several theories attempting to explain the phenomenon. The most common include over-cleanliness, distance from the equator, and vitamin D deficiencies.
In places like Melbourne, these could all be coming to a head.
There are potential links, none of them conclusive, between low vitamin D levels and a lack of exposure to immune-system triggers like pets and siblings that are combining to create Melbourne’s localized high rates of allergens.
Australia is one of the few developed countries, for example, that doesn’t require vitamin D be added to milk sold in stores. Melbourne is often cited as the “cleanest city in the world” with a cultural expectation that has many parents striving for germ-free homes. These could be combining to create a higher risk rate.
In Europe, for example, some communities are moving child daycare centers so that they’re closer to farms and dairies, where it’s been found that dust from the agricultural activity actually boosts an immuno-protein called A20 which protects from inflammation responses.
In the end, the reasons for rising food allergies are still a mystery, but scientists do admit that they’re getting closer to a good understanding of them and could find ways to limit, reduce, or even eliminate them within the relatively near future.