Dogs May Protect Kids From Allergies
Infants in Homes With 2 or More Dogs May Be Less Likely to Wheeze
Dec. 5, 2006 -- Infants who live in a house with multiple dogs may be less
likely to develop allergies later in life, according to a new study.
Researchers found that infants who live in a home with two or more dogs and
a high level of certain types of a bacterial substance were a third less likely
to develop wheezing in the first year
of life than those who didn't live with dogs.
Wheezing in infants is associated with a higher risk of developing allergies
and asthma later in life.
Dogs May Protect Infants
In the study, researchers looked at the effects of pet ownership on wheezing
in more than 500 infants at high risk of developing allergies because at least
one parent had them.
The results, published in the Journal of Allergy and Clinical
Immunology, showed that wheezing was not independently associated with
either dog or cat ownership, or a high level of indoor endotoxins.
Endotoxins are natural compounds produced by bacteria. Some believe exposure
to these compounds may stimulate the immune system.
However, infants living in a household with two or more dogs and a high
level of indoor endotoxins (measured from house dust) were a third less likely
to develop wheezing than infants living without dogs.
"Our bodies are programmed to produce allergic responses early in
life," says David Bernstein, MD, professor of immunology at the University
of Cincinnati, in a news release. "But there are environmental factors like
bacterial endotoxins that may modify the immune system and block development of
allergies early in life.
"We do not yet understand how and why exposure to high levels of
bacterial endotoxins and multiple dogs in the home exert a protective effect in
these high-risk infants from wheezing early in life," says Bernstein.