Asthma up, healthy habits down. Could there be a connection?

Philip J. Goscienski, M.D.

February 2012

Asthma is a narrowing of lung air passages that results in shortness of breath and difficulty breathing. It varies among population groups and from one region to another. Tobacco smoke, infection, dust, chemicals and even emotional stress can trigger an asthma attack. There is clearly a genetic influence; a child whose both parents have asthma has a 70 percent chance of having the disease. The incidence of this disease more than doubled among children in the years between 1980 and 1995. It has since stabilized but at a relatively high level.

Researchers look for clues in lifestyle and environment. Could something have changed between 1980 and the mid-90s to explain the rise in asthma? There are several candidates but none has been unequivocally linked to the spike in incidence.

One of the factors that have increased significantly is childbirth by C-section, which now represent more than one-third of deliveries. Asthma researchers note that babies that bypass the normal birth canal fail to become colonized by beneficial bacteria, a factor in the normal development of the immune system. Several studies have shown that the risk of asthma increases by as much as 20 percent in children born via C-section.

A consistent finding is that mothers who smoke during pregnancy and afterward put their children at risk of developing asthma. The observation that smoking during pregnancy increases the risk by about 30 percent suggests that it is not just inhalation of cigarette smoke that does harm but some chemical in tobacco.

Children's intake of fast food has increased markedly since the 1970s and the near-absence of fruits and vegetables in their diet is a real concern to nutritionists. So is the very low intake of omega-3 fats, which have a moderating effect on inflammation, a major factor in asthma. One study showed that as fast food intake increases, so does the likelihood of asthma, while another concluded that a Mediterranean-type diet that is high in fruits and vegetables had the opposite effect. Fruits and vegetables in general and antioxidants in particular seem to be of benefit.

The multiplicity of factors that affect asthma may never be untangled but there are some recommendations that make sense, especially for women who are pregnant: eliminate tobacco use, limit fast foods, eat more fruits, vegetables and fish and seek out cleaner air. That's not a bad idea for everyone.

Philip J. Goscienski, M.D. is the author of Health Secrets of the Stone Age, Better Life Publishers 2005. Contact him at drphil@stoneagedoc.com.