Asthma, hay fever, eczema and food allergies are all "allergic diseases" caused by your immune system responding to substances that are ordinarily harmless, such as pollen or peanuts. Autoimmune diseases, which include lupus, MS, Type 1 diabetes and inflammatory bowel disease, also result from your body‘s defense mechanisms malfunctioning, causing your immune system to attack parts of your body such as your nerves, pancreas or digestive tract.
Experts estimate that many allergies and immune-system diseases have doubled, tripled or even quadrupled in the last few decades. Some studies indicate that more than half of the U.S. population has at least one allergy.
Many researchers suspect the increase has an explanation rooted in aspects of modern living -- including the "hygiene hypothesis," which blames growing up in increasingly sterile homes. Others have pointed to changes in diet, air pollution, and even the rise in obesity and sedentary lifestyles.
One reason that many researchers suspect something about modern living is to blame is that the increases show up largely in highly developed countries in Europe and North America. The illnesses have only started to rise in other countries as they have become more developed. As society in general becomes more “sterile,” it is causing real problems for your immune system, which is becoming increasingly unable to differentiate between real threats and harmless things like pollen and dust-bunnies.
Think about it: how many people do you know who carry a bottle of antibacterial hand sanitizer with them wherever they go? Meanwhile, you’re exposed to antibiotics, in your food and by prescription, while most of the food supply is pasteurized or otherwise treated to remove both good and bad bacteria.
And this is the key: while everyone was so busy killing all of those “germs,” they didn’t stop to think about what this would mean for the future generations. Children are now growing up without being exposed to the bacteria, viruses and parasites that have existed throughout the world -- even in developed countries like the United States -- since the beginning of time.
To some extent, this is a good thing. But to children’s immune systems, which are not being exposed to bacteria and viruses like they were in the past, it results in an excessive immune response against a routine thing, like a peanut, resulting in allergies and autoimmune diseases.
An Overly Sterile Immune System is Not a Good Thing
Simply speaking, your immune system is composed of two main groups that work together to protect you. One arm of your immune system deploys specialized white blood cells, called Th1 lymphocytes, that direct an assault on infected cells throughout your body.
Counterbalancing this, another arm of your immune system attacks intruders even earlier. It produces antibodies that try to block dangerous microbes from invading your body's cells in the first place. This latter strategy uses a different variety of white blood cells, called Th2 lymphocytes. The Th2 system also happens to drive allergic responses to foreign organisms.
At birth, an infant's immune system appears to rely primarily on the Th2 system. But the “hygiene hypothesis” suggests that the Th1 system can grow stronger only if it gets exercise, either through fighting infections or through encounters with certain harmless microbes. Without such stimulation, the Th2 system flourishes and the immune system tends to react with allergic responses more easily.
In other words, the hygiene hypothesis posits that children not being exposed to viruses and other environmental factors results in their not being able to build up resistance. This could make them more vulnerable to illnesses later in life.
A Little Bit of Dirt is Healthy
Numerous studies have provided very compelling evidence that your body actually benefits from regular exposure to dirt. So when a child is exposed to a bit of bacteria, their immune system does what it’s supposed to: develop a tolerance to it. Here’s a summary of what has been found so far:
- Kids who are overly hygienic are at an increased risk of developing wheezing -- a symptom of asthma -- and eczema. A study in the Archives of Disease in Childhood found that children with the highest degree of personal hygiene -- those who washed their faces and hands more than five times per day, cleaned before meals, and bathed more than two times each day -- were the most likely to develop eczema and wheezing.
- Kids who grow up in extremely clean homes are more likely to develop asthma and hay fever than kids who grow up on farms or in houses with a little bit of dirt, according to a 2002 study in The New England Journal of Medicine.
- Children who are raised with pets, or who have older siblings, are less likely to develop allergies, possibly because they are exposed to more bacteria.
Well, if you’re an adult who already has allergies, please read through my past advice on how to get rid of your allergies for good. If you are a parent, please realize that the future of your child’s immune system is in your hands. You can help it to build up the resistance it needs by: