Those of us who are a certain age may remember when food allergies weren’t talked about much. Today, they’re a common focal point in school lunchrooms where allergic kids can sit at “safe zone” lunch tables and on restaurant menus that disclose allergenic ingredients. Tragically, they’re also in the headlines as we read about deaths due to food allergies.
Times they are a-changing, and an increase in food allergies is an indisputable part of that change. Consider these statistics:
- Food allergies increased 50% between 1997 and 2011 (Centers for Disease Control)
- Peanut allergies have increased 21 percent since 2010 (American College of Allergy, Asthma, and Immunology)
- Food allergies affect up to 6% of children and 4% of adults (American College of Allergy, Asthma, and Immunology).
What Causes Food Allergy
Before we explore why food allergies may be increasing, let’s look at why these allergies occur in the first place. It’s important to note here that there’s nothing inherently wrong with peanuts, shellfish, eggs, or other allergenic foods. The problem is the body’s reaction to the proteins found in these foods. When you bite into a PB & J sandwich or down a handful of peanut M&Ms, the body should simply ignore the peanut proteins. But the immune system of an allergy sufferer may mistake these proteins for enemy invaders and marshal their resources to fight them off. This defense includes releasing chemicals into the body that trigger allergy symptoms.
Common food allergy symptoms include:
- Itching or swelling of the lips or tongue
- Gastrointestinal problems (gas, cramping, diarrhea, etc.)
- Skin rash
- Runny or stuffed-up nose
- Recurring sinus or ear infections
Are all foods allergenic?
While many foods can trigger reactions, there are eight foods that are responsible for at least 90 percent of food allergies:
- Tree nuts
*Note that peanuts get their own category because they aren’t technically nuts but a type of legume.
Why are Food Allergies Becoming so Common?
Spoiler alert: The truth is that no one knows this answer for certain, but we do have some strong hypotheses. For the remainder of this article, we’ll explore these possibilities.
Overreporting. While there’s no doubt that food allergies are increasing, there’s some thought that because they are such a hot-button topic right now, some people might jump to the conclusion that they have a food allergy when they merely have a food sensitivity. Food sensitivities tend to center on gastrointestinal symptoms (such as stomach discomfort after drinking milk). They are not usually accompanied by other allergy symptoms, and they don’t have the potential to be life-threatening like allergies do.
Pollution. A study published in Clinical and Experimental Allergy showed a correlation between smoking/air pollution and sensitization to food allergens.
Hygiene hypothesis. Some studies have shown that we’re just too clean in this modern world. As a result, our bodies lack experience discerning and fighting off certain types of bacteria and illness. Scientists have noted that the immune function associated with fighting off parasites is similar to that used to fight against allergens. But because we don’t encounter parasites nearly as often as our ancestors did, we lack experience and sometimes overreact to stimuli (such as food proteins) that pose no danger to our bodies.
Further substantiating the hygiene hypothesis are studies showing that kids raised on farms are less likely to develop allergies. This could be owing to their increased exposure to dirt and farm animals. Another supporting study showed that kids without dishwashers were less allergy-prone.
Vitamin D. The rise in food allergies has been linked to both the increase and decrease of Vitamin D in our lives. One study published in Clinical and Molecular Allergy showed that we don’t get enough Vitamin D in the form of sunlight anymore. Another study in the Journal of Pediatrics showed that we get more Vitamin D than ever from an increase in dairy products in our diets. Either way, these studies showed a correlation between Vitamin D and food allergies.
Dual-allergen exposure hypothesis. One of the tenets of this hypothesis is that lack of exposure to trigger foods can drive up the risks for food allergies. Conversely, it’s believed that eating allergenic foods during weaning from breastfeeding can help prevent the development of allergies. The King’s College London’s LEAP Study helped verify this hypothesis, showing an 80% decrease in peanut allergy in 5-year-old children who regularly ate peanut proteins starting in their first year of life.
Supporting this idea is research that shows that migrants have higher food allergy rates. This could be due to the immune system’s tendency to reject foods that it has not been conditioned to in its earliest years.
Fortunately, as food allergies increase, so does the medical science devoted to treating them. Sublingual immunotherapy, which involves taking under-the-tongue drops that desensitize the body to food allergens, gives hope to food allergy sufferers. The treatment is allowing people to eat more foods without the fear of allergic reactions that once troubled them. Click here to learn more about sublingual immunotherapy for food allergies.