Is asthma preventable?

The development of asthma
is thought to arise from complex and poorly understood
interactions involving a person’s inborn genetic
characteristics and elements of the environment in which
he or she lives, from birth onward. Each of us is endowed
with a specific set of genes, inherited from our parents,
and there is obviously nothing we can do to alter our
genetic makeup.We might thus logically turn our focus
to what constitutes the elements of the environment in
which we live to see if any preventive measures could
prove helpful. An emerging body of scientific evidence
suggests that infection with certain common strains of
respiratory viruses early in life may predispose a child to
develop asthma. Although interesting and a guide for
additional research into such viruses and their relationship
to asthma, the observation does not carry practical
“real life” implications. How, indeed, to avoid a common
respiratory virus? There is no feasible way for any of us
to avoid catching one!

Over what other parts of our environments might we
have more “control”? We can, of course, modify specific
exposures in our indoor environments and in particular,
in our homes. In 2000, the Institute of Medicine published
a report called Clearing the Air: Asthma and
Indoor Air. It reviewed the available scientific evidence
about indoor air exposures and asthma. One aspect of
the report looked at those exposures that might represent
risk factors for the development of asthma. It concluded
that there is sufficient scientific evidence to
support a causal relationship between the development
of asthma and exposures to house dust mites as well as
a strong association between exposure to secondhand
smoke (called ETS for environmental tobacco smoke)
and asthma in younger children. The ETS exposure
included prenatal exposure. Exposure to cockroaches
and to the respiratory syncytial virus (RSV) were less
clear-cut risks for asthma, but both appeared to
increase the risk. Not everyone at an increased risk for
asthma will inevitably go on to develop the condition,
but it is both prudent and reasonable to decrease or
eliminate exposures to known risk factors as much as is
possible.