• Researchers looked at the data of more than 66,000 children in Japan
  • Exposure to dogs led to reduced incidence risks of egg, milk and nut allergies
  • Exposure to cats reduced the risk of allergies to egg, wheat and soybean

Having pet cats and dogs can be a joy, and it appears that there may be another benefit to living with them. Researchers have found that kids who were exposed to pet cats or dogs had reduced risk of certain food allergies.

For their new study, which was published Wednesday in PLOS (Public Library of Science) ONE, a team of researchers analyzed the data of 66,215 children in Japan, including information on their pets and food allergies. The idea, they said, was to look at the effects of exposure to various types of pets on the risk of having food allergies.

The hygiene hypothesis proposes that exposure to germs or infections during childhood may help the immune system develop and differentiate the harmful from non-harmful substances, thus preventing its overreaction. This, the hypothesis suggests, may be why kids who grew up in rural areas, where they live around animals and larger families, develop asthma less often.

"The hygiene hypothesis suggests that pet exposure is effective in preventing allergic disease, and some studies have reported the beneficial effects of dog exposure during fetal development or early infancy on food allergy," the researchers wrote. "However, the effects of exposure to pets other than dogs on the kinds of food allergies remains unaddressed."

The researchers found that the kids who were exposed to pet cats or indoor dogs during fetal development or early infancy actually had reduced risk of food allergies. More specifically, exposure to dogs reduced the incidence risk of egg, milk and nut allergies. Meanwhile, exposure to cats reduced the risk of allergies to eggs, wheat and soybean.

In the U.S., egg, milk, nut, wheat and soybean are among the nine major food allergens.

"These findings reduce concerns about the development of allergic diseases caused by keeping dogs and cats," the researchers wrote. "Reducing the incidence of food allergies will significantly reduce childhood mortality from anaphylaxis."

It's worth noting that "there was no significant difference for children in households with outdoor dogs," PLOS noted in a release. They didn't observe statistical associations with pet turtles and birds, either.

Interestingly, exposure to hamsters had the opposite effect to that of dogs and cats in that it "might increase the risk of nut allergy."

Overall, the results show that the supposed benefit of exposure to pets may depend on the type of allergy and the species of the pet, the researchers said.

They said their work didn't determine if the link was causative, according to PLOS. Furthermore, the data was self-reported, thus relying on the participants' recollections.

In the future, oral food challenges would be needed to note food allergy incidences more accurately and objectively.

"To the best of our knowledge, this is the largest birth cohort study on the association between pet exposure and food allergy risk," they wrote.

Their findings, according to them, could help in designing future studies.

Dog and Cat
Pictured: Representative image of a dog and a cat. Pixabay