In the past 20 years, severe allergy cases have doubled in developed countries. We live under de impression that all kids are allergic to something.
There are several theories to explain this alarming increase: food conservants, increased exposure to chemicals and population explosion are among the preferred. But recently, another theory is gaining impulse: the lack of dirt.
Hygiene hypothesis: mentioned in a National Geographic Article (suggested readings below), this hypothesis says that modern immunological systems, from people that grew in practically sterile urban environments, may not have been trained in the infanthood, becoming susceptible when in contact with exotic and strange substances as pollen, dog’s and cat’s hair, fungus among others.
Modern life brought good medical care and have also reduced contagious diseases, but brought also an excessive care for cleaning. This has reduced children’s contact with some agents found in dirt. And this lack of exposure may be what is causing the increase in allergy cases.
The hypothesis is not simple and has also caused a great controversy, but some facts are intriguing and point towards its direction:
- Respiratory allergies are more common in rich society than in poor ones;
- Children that attended daycare are less susceptible to develop allergies;
- There are less allergy cases among people raised in the countryside than among the ones raised in the cities;
- People that live in farms, having frequent contact with farm animals, rarely develop allergies.
This hypothesis is based on the fact of us being exposed or not to certain agents in our infanthood, when our immune system is still learning and getting trained to defend our bodies against external aggressions.
Therefore, sleeping outside, drinking water from creeks and having contacts with farm animals, despite how fun it may be, would not help an adult immune system, which is already not trained and is sensitive to the substances strange to our infancy.
In this case we would have to rely only on medicine to reduce the symptoms, treatments to reduce our sensitivity or, the most efficient solution toward allergies: avoiding contact with what is causing it.
It is already too late for us, but, if this hypothesis is right, there is still hope for our kids. They are training their immune systems and, a little bit dirt may be helpful. At least some kind of dirt.
As most of us are not ready to share the living room with cows, despite the fresh milk, we could, at least, relax a bit with the cleaning. There is no need to live in a filthy home, but there is also no need to sterilize it. Making the baby to share its bed with six cats or put it to roll with dogs in the backyard may not be necessary – nothing against it as well – but, if the animals are calm, healthy and vaccinated, what’s the problem with some dog saliva in the face?
Additionally, this may serve as an excuse when arguing with the in laws about taking the baby for a hike or to camp. I already have a baby-trip backpack to take my kid to the jungle. If this text convinces my mother in law, off course.
Attention – The hygiene hypothesis is only a theory that tries to explain the recent allergy cases proliferation and is not, per se, a treatment or prophylactic. It is also not the immediate solution to this problem that attacks millions of people across the world.
And, as we are criticizing excess cleaning, we must remember that cleaning products are potent chemicals, which are also being investigated as causes of allergies and other modern diseases. Use them as indicated, do not overuse, and avoid direct contact, especially by children.
Allergy cases require medical attention. Only physicians can orient and follow the treatment of these diseases. See you and relax on the cleaning for a change.
Newman, Judith. Misery for all seasons. Allergies: a modern epidemic. National Geographic Magazine, May 2006.
Achenbach, Joel. Who Knew? Allergies. Down and Dirty. National Geographic Magazine, September 2002.