Why are food allergies more common in children than adults?

The incidence of food allergy is much higher for children than for adults. The reason for the much higher rate among kids is partly the result of the fact that most people "outgrow" their food allergies, peanuts being the exception. Only 10 to 20 percent lose their peanut allergy as opposed to 90 percent for other foods. Milk allergy is often the result of an immature digestive system that can't handle the complex proteins at an early age, but that eventually does mature.

Children's immune systems are not as developed or as robust as adults' immune systems. When a child's immune system is in flux, he is at increased risk of developing food allergies. This is why doctors recommended waiting to introduce solids until 6 months and then introduce one new food a week.