Skip Navigation
Archive

NIAID Archive

Important note: Information on this page was accurate at the time of publication. This page is no longer being updated.
​​
NIH HHS News Release Logo
National Institute of Allergy and
Infectious Diseases (NIAID)
http://www.niaid.nih.gov

FOR IMMEDIATE RELEASE
Tuesday, Aug. 27, 2002

Media Contact:
NIAID Press Office
(301) 402-1663
niaidnews@niaid.nih.gov
Skip Content Marketing
  • Share this:
  • submit to facebook
  • Tweet it
  • submit to reddit
  • submit to StumbleUpon
  • submit to Google +

Multiple Pets May Decrease Children's Allergy Risk

Children raised in a house with two or more dogs or cats during the first year of life may be less likely to develop allergic diseases as compared with children raised without pets, according to a study in the August 28 issue of the Journal of the American Medical Association. The study was supported by the National Institute of Allergy and Infectious Diseases (NIAID) and the National Institute of Environmental Health Sciences (NIEHS).

"The striking finding here is that high pet exposure early in life appears to protect against not only pet allergy but also other types of common allergies, such as allergy to dust mites, ragweed, and grass," says Marshall Plaut, M.D., chief of the allergic mechanisms section at NIAID. "Other studies have suggested a protective effect of pet exposure on allergy and asthma symptoms, but generally have looked only at whether pet exposure reduced pet allergy. This new finding changes the way scientists think about pet exposure; scientists must now figure out how pet exposure causes a general shift of the immune system away from an allergic response."

In their paper, lead author Dennis R. Ownby, M.D., of the Medical College of Georgia, and colleagues suggest that bacteria carried by pets may be responsible for suppressing the immune system's allergic response. These bacteria release molecules called endotoxins, and endotoxins are believed to shift the developing immune system away from responding to allergens through a class of lymphocytes called Th-2 cells, which are associated with allergic reactions. Instead, endotoxins may stimulate the immune system to activate Th-1 cells, which may block allergic reactions.

The researchers followed 474 children from birth to six or seven years of age. When the children were one year old, the researchers contacted parents by telephone to find out how many pets were in the home. When the children were two years old, researchers measured the level of dust mite allergen in their bedrooms. When the children were six or seven, the researchers tested them for allergic antibodies to common allergens by two approaches — a skin prick test and a blood measurement.

After adjusting for factors such as dust mite allergen levels, parental smoking, and current dog or cat ownership, the researchers found that children exposed to two or more dogs or cats during the first year of life were on average 66 to 77 percent less likely to have any allergic antibodies to common allergens, as compared with children exposed to only one or no pets during their first year.

"Our findings suggest an area of research with many possibilities, one that could potentially bear fruit over the next decade or so," says Dr. Ownby. "If we could find out exactly what it is about pets or the bacteria they carry that prevents the allergic response, scientists might be able to develop a new allergy therapy based on that knowledge."

NIEHS is the component of NIH that conducts and supports research on the environmental causes and triggers of disease and our human susceptibility to them.

###

###

References:


DR Ownby et al. Exposure to dogs and cats in the first year of life and risk of allergic sensitization at 6 to 7 years of age. Journal of the American Medical Association 288(8): 963-72 (2002).


NIAID conducts and supports research—at NIH, throughout the United States, and worldwide—to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID Web site at www.niaid.nih.gov.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

NIH...Turning Discovery Into Health ®

back to top


Archive

NIAID Archive

Important note: Information on this page was accurate at the time of publication. This page is no longer being updated.
​​​​

Last Updated August 27, 2002