Daycare good for your child’s health
Another reason to stop beating yourself up over sending Junior to daycare: new UK research suggest that kids in daycare have a 30% lower risk of developing the most common type of childhood leukemia. The new research is the first comprehensive analysis of studies investigating the association between social contact and childhood leukemia.
“Combining the results from these studies together provided us with more confidence that the protective effect is real. Analyzing the evidence in this way gives a more reliable answer to the question and a more precise estimate of the magnitude of the effect,” says study leader Dr Patricia Buffler, professor of epidemiology at the School of Public Health of the University of California, Berkeley.
While the analysis doesn’t reveal how intense social contact might ward off childhood leukemia, it bolsters the theory that children exposed to common infections early in life gain protection from the disease. It’s known that environments such as daycare centers increase the chance of infections spreading (that’s the reason your child catches so many colds!). Some experts reckon that if a child’s immune system isn’t challenged early in life – as it will be at a busy daycare center – it may mount an inappropriate response to infections encountered later in childhood and that this could provoke the development of leukemia.
Leukemia is the most common cancer found in children in the industrialized world, affecting about one child in 2,000. Incidence of the disease has been on the increase for decades. Acute lymphoblastic leukemia, or ALL, the type of leukemia the studies focused on, accounts for more than 80% of cases and most often occurs in children aged between 2 and 5 years of age. Scientists believe that for most types of childhood leukemia to develop, there first must be a genetic mutation in the uterus, followed by a second trigger during childhood that results in 1% of those children developing the disease. Infection – or the timing of infection – is one of the suspected triggers.
Dr Buffler’s analysis included 14 published studies comprising a total of 6,108 children with leukemia and 13,704 without the disease. Parents were asked about daycare and playgroup attendance, as well as other forms of social interaction with other children. The studies varied in the timing, duration and extent of social contact investigated and in the age groups and types of leukemia studied. Twelve of the studies found some indication of a protective effect of social interaction with other children, while two found no effect. No study found that social contact increased the risk of childhood leukemia.
“Our analysis concluded that children who attended daycare or playgroups had about a 30% lower risk of developing leukemia than those who did not,” says Dr Buffler. “Combined results for studies of daycare attendance specifically before the age of 1 or 2 showed a similarly reduced risk.”
The protective effect became even stronger when the researchers omitted five studies in which the selection of healthy children for the comparison group relied on methods not considered optimal. In that analysis, children exposed to social contact were almost 40% less likely to go on to develop leukemia than their counterparts.