There has been an alarming increase in food allergies in recent years, especially among children. It has been reported that the number of children suffering from food allergies has jumped by nearly 20% in 10 years, with serious cases becoming increasingly common.

The biggest increase appears be peanut allergies. A reported 1 in 50 children in Canada are now allergic to peanuts – twice as many as in 1990.

So what’s behind this quasi-exponential growth?

For now, there seems to be more questions and hypotheses than answers, but researchers are increasingly looking at environmental factors to explain this growing prevalence of food allergies.

A matter of hygiene

Hygiene conditions have vastly improved in recent decades. Our food is washed several times, we wash our hands frequently, we take antibiotics and we get vaccinated. The flip side of this coin is that our war on dirt and germs can seriously disrupt our immune system. When it no longer has to work so hard to fight off bacteria and infections, our immune system develops antibodies to otherwise harmless substances. The development of allergies is therefore a result of a delayed maturation of the immune system due to a low exposure to infectious agents.

A matter of genes

Genetics also appear to play a role in the prevalence of allergies. For example, if a family member suffers from an allergy, other members in that family are more likely to suffer from an allergy as well (although not necessarily the same one).

Children whose parents already have an atopic disease such as dermatitis, eczema, asthma or seasonal/animal allergies are also more likely to suffer from food allergies.

A matter of diet

Our diet has changed enormously in the last few decades. We eat fewer omega-3 fatty acids and antioxidants than our grandparents did, and this may also be affecting our immune system. What’s more, children now consume a much wider variety of foods at a younger age than they did in the past. Allergies that were never heard of in the past, such as to mustard, soybeans or kiwis, are becoming increasingly common. A lack of exposure to vitamin D is yet another suspected cause of allergies.

In short, the number of people suffering from food allergies seems to be increasing at the same pace as our awareness of their impacts. So is hygiene, exposure to germs or urban pollution the real culprit? It’s all still hypothetical. One thing is certain, however. Allergists now recommend that children as young as 6 months of age be introduced to all food allergens, arguing that it’s preferable to “train” the immune system for these main food allergens early on because it will reduce the risk of them triggering allergies later in life.