The study was conducted in Australia by Murdoch Children’s Research Institute, and was headed by Dr. Justine Ellis.
The research indicated that the risk of juvenile arthritis in a child with no siblings was twice as high as a child with siblings.
Juvenile arthritis, one of over 100 types of arthritis, is an immune disorder.
Researchers compared 302 children with juvenile arthritis to over 1000 children without arthritis and found a protective association with sibling exposure, especially for exposure to three or more siblings.
The study found a clear pattern of association emerged in which greater exposure to siblings by six years of age was associated with a reduction in juvenile arthritis risk. Exposure to younger siblings appeared particularly important.
Dr. Ellis said the finding suggests that increased exposure to microbes such as bacteria in childhood may protect against the development of juvenile arthritis.
“In other words,” Ellis said, “the findings provide further support for a role of the ‘hygiene hypothesis’, in combination with genetic factors, in the development of juvenile arthritis.”
The genetic makeup of juvenile arthritis is becoming clearer, with 17 genes now associated with disease risk. However, until now evidence for environmental risk has remained unclear.
“Our study showed exposure in the first six years of life to siblings may decrease the risk of juvenile arthritis,” said Ellis
“This could be due to the fact that contact with siblings may provide protection by exposing children to infections and germs and building an immune system less susceptible to the development of juvenile arthritis,” Ellis explained.
Researchers observed the sibling exposure in the context of getting exposed to more infections, if a sibling is present in the house. The hypothesis is that this causes the child to develop a stronger immune system.
This, in turn, might assist in preventing the immune disorder of juvenile arthritis.
Source: Sunshine Coast Daily