Food allergies are not the same throughout the world. While much attention has been paid to the big eight allergens—soy, milk, eggs, wheat, peanuts, tree nuts, fish and shellfish—these are not necessarily the major sources of allergies outside of North America and western Europe. More research is finding that allergens that are more common in Asia are less common in the west, and that there are also important differences between Asian countries. These differences are important to understand to better help children around the world, especially when they move from one region to another.
Types of Food Allergies in Asia
While here in the U.S. and North America we talk about the big eight, these are not necessarily the major allergens for children in Asia. What is the same or similar is the overall incidence in children. In terms of types of foods that affect Asian children, shellfish tops the list. This is one of the big eight in the west, but not number one. It is likely the most common food allergen in Asia because shellfish is a major food source throughout the region.
In the west, the top allergen is the peanut, but peanuts are not major sources of allergies for children in Asia. In fact, peanut allergy rates are extremely low there. Peanuts are part of the diet in many areas of Asia, so why it is such a rare allergy is not yet understood. Among infants and the youngest children in Asia, milk and egg are the most common food allergens.
Children in Asia also have allergies to unique foods that are rarely seen in the west. For instance, a Chinese delicacy known as bird’s nest is made from cave swallow nests. These nests are made from the birds’ saliva. It is a known allergen in a significant portion of children in some parts of Asia.
There are also allergies to foods that are available in the west but that are eaten more often in Asia. For instance, chickpeas are a staple food in India, and allergies to them are much more common than in the west. Other allergens in Asia that are non-existent or uncommon in the west include chestnuts, buckwheat and royal jelly.
Food Allergy Differences Within Asia
Within the region there are differences in the prevalence of food allergies and the types of allergens that are most common. For instance, while overall peanut allergies are extremely low, in Singapore the incidence of allergies to peanuts is high. Interestingly, 15 years ago, peanut was not a major trigger here but bird’s nest was. This could indicate a change in allergies is occurring as diets change. Now, there are significant numbers of peanut allergies in Singapore and fewer bird’s nest allergies.
Another regional difference is wheat as an allergen. Wheat is much more prominent in Japan and South Korea than in other Asian countries. It is the leading cause of anaphylaxis in children in these two locations. Furthermore, while shellfish used to be the most common cause of food dependent exercise-induced anaphylaxis in South Korea and Japan, wheat has replaced it. Wheat allergies are also on the rise in Thailand and Singapore.
The differences between food allergies between west and east are informative, especially as allergens and incidences change in the east. The changes may reflect changing diets that are becoming more like diets in the west. More research may help uncover explanations for increasing rates of food allergies in the west.