Q: Since my 6-year-old has multiple allergies (peanuts, tree nuts, soy and sesame), people ask me all the time: why are there so many food allergies today? Do you have a good shorthand answer?
Dr. Sicherer: The shortest answer is we do not know exactly and the long answer could involve writing a tome. There are theories based on our rapid change in lifestyle over the past decades.
The theory with the most traction is about our relationship to germs, the hygiene hypothesis. The hygiene hypothesis relates to the fact that we live clean. We protect ourselves from germs with medications. We wash frequently, have smaller families, and live away from farms and animals.
The hygiene hypothesis suggests that our immune system is looking for a fight and, without a steady challenge of harmful germs, it ends up misdirected, attacking innocent proteins in our food.
This is not an advertisement to allow ourselves to get dangerous infections, but it may be an explanation to why, as a society, we see more allergy – an immune attack on innocent proteins from the outside – and more autoimmune disease – an attack on innocent proteins on the inside. It also presents a research opportunity to learn about the good bacteria that inhabit our bodies and how to manipulate them to our benefit.
Diet and Lifestyle Theories
Think about other changes in lifestyle with computers and cell phones and our fast-paced, unhealthy diet. We are eating bad fats, not getting as much exercise, becoming obese, and so on. There are theories that these changes affect our immune systems.
Similarly, we use more sunscreen and spend less time outdoors, reducing our body’s natural production of vitamin D. This vitamin, in the proper amounts, may ensure a healthful immune system. Sun safety is important, but there may be consequences that require attention with supplementation.
Additional factors include the way food is processed, the timing of food introduction to children, pollution, and other environmental factors.
The short answer is that this epidemic undoubtedly includes overlapping influences of many factors.
Dr. Scott Sicherer is a practicing allergist, clinical researcher and professor of pediatrics. He is Director of the Jaffe Food Allergy Institute and Chief of Pediatric Allergy and Immunology at the Icahn School of Medicine at Mount Sinai in New York. He’s also the author of Food Allergies: A Complete Guide for Eating When Your Life Depends On It.