You heard right. According to a study referred to here, children born by c-section are 80% more likely to develop asthma.
Scientists are unclear of the reason, but there are theories. First off, one must be aware that asthma is an auto-immune disorder that only those who have the asthma gene will have a chance to acquire. In most cases it is caused in infancy when the immune system is forming.
One great theory is the hygeine theory, in which scientists believe we as humans have worked so hard to clean up the way we live to prevent the spread of disease that we have literally cleaned ourselves into some new diseases, and one of them is asthma.
Your immune system ideally is supposed to attack bad parasites and bacteria. It is believed that the immune system has to constantly be stimulated. Absent bad bacteria and bad parasites, the immune systems of some people get bored and start to attack good things, like harmless dust mites, molds, animal dander, cockroach urine and stuff like that (common allergens).
One such theory, according to MedicineNet.com, has scientists thinking, "babies born via C-section have impaired immune cell function because of suppression of regulatory T cells, which regulate the development and function of the immune system."
Basically, children born by c-sections have immature immune systems. The same thing is believed to be true of babies born pre-maturely.
The study, presented at the American Thoracic Society's 2008 Conference in Toronto, "suggests that the stress and process of labor itself or exposure to specific microbes through the birth canal in vaginal rather than C-section delivery may influence neonatal immune responses."
This study significantly impact the decision by many people to have elective c-sections, especially by parents who have a history of allergies and asthma (and probably have the asthma gene).
Stay tuned, because in a future post here at the RT Cave I will explore other possible causes of asthma, or things that might turn the asthma gene to the on position. Stay tuned.