OIn a study published January 11, 2019 in Nature Communications, researchers showed that blocking a particular set of signals from these cells causes female (but not male) mice to build extraordinarily strong bones and maintain them into old age, raising hopes for new approaches to preventing or treating osteoporosis in older women. "Our collaborators who study bone for a living said they'd never seen bone this strong," said study senior author Holly Ingraham, PhD. "Our current understanding of how the body controls bone growth can't explain this, which suggests we may have uncovered a completely new pathway that could be used to improve bone strength in older women and others with fragile bones." More than 200 million people worldwide suffer from osteoporosis, a weakening of the bones to the point where falls or even minor stresses like bending over or coughing can trigger fractures. In healthy individuals, bone tissue is constantly being recycled -- old bone tissue is broken down and replaced by new bone. As we age, this cycle tilts in favor of bone loss, causing our bones to become increasingly porous and fragile. Women are at particularly high risk of osteoporosis after menopause (nearly one in three post-menopausal women in the U.S. and Europe suffer from weakened bones) because of declining levels of the sex hormone estrogen, which normally promotes bone growth.