Playgroups, Daycare Cut Leukemia Risk

Enrolling your kids in a preschool, playgroup or daycare center could reduce their risk of getting leukemia by 30-40%, a study finds. Exposing children to other youngsters at a tender age toughens their immune systems, which researchers infer helps them stave off the cancer.

Scientists believe childhood leukemia begins with a genetic mutation in the womb, and is then triggered by an infection in childhood. That theory remains unproven, but researchers say their survey, which reviewed results of 14 studies involving almost 20,000 children, provides compelling evidence. (More leukemia stories.)