NEW YORK - Some people prone to allergies keep
their homes pet-free, a study shows -- but such "avoidance" of furry companions
only partly explains the lower allergy risk found among pet owners.
The findings, published in the Journal of Allergy and Clinical Immunology,
lend some support to the theory that growing up with a pet trains the immune
system to be less reactive to potential allergy triggers.
A number of studies, for instance, have found that children exposed to a cat
or dog early in life are less likely to develop allergies and asthma.
On one hand, this could indicate a protective effect of pets on immune system
development. But an alternative explanation is that families with a genetic
tendency toward allergies often opt for a pet-free home, whereas those with an
inherently lower risk are more likely to keep pets.
To investigate this question, researchers used data from 9,812 European
adults who took part in a 9-year study of respiratory health. Participants were
asked about childhood allergy and asthma symptoms, as well as their exposure to
pets throughout life.
The researchers found that when people developed allergies or asthma as
babies or pre-schoolers, their families were less likely than others to get a
cat or keep a cat they already had. However, this was not true of families where
a parent had allergies or asthma.
And while people with both current and childhood asthma were less likely to
have a cat in adulthood, childhood symptoms alone did not prevent adults from
getting a pet.
In general, adults who had pets before developing respiratory problems
usually kept the animal, according to the researchers, led by Dr. Cecilie Svanes
of the University of Bergen in Norway.
"People appear to prefer taking asthma medication rather than getting rid of
a beloved pet," the researchers write, "which seems reasonable."
Like many previous studies, the current one found that pet owners had a lower
risk of allergies - one third lower than that of their pet-free peers. But "pet
avoidance" among allergy sufferers explained only part of this relationship.
"Thus," the researchers write, "although selective avoidance is certainly
present, it appears to account for only a part of the protective effects of pets
presented in the literature."
However, even if pets exert a true protective effect, experts don't recommend
running out and buying a furry friend to prevent young children from developing
allergies. If a child is already sensitive to pet dander, this will worsen the
situation.
