Researchers at UCSF and UC Davis solved a long-standing puzzle on how the bones of breastfeeding women stay strong even as they lose calcium to milk Their results, published July 10 in Nature, solve a long-standing puzzle about how women’s bones remain relatively robust during breastfeeding, even as calcium is stripped from bones to support milk production. More than 200 million people worldwide suffer from osteoporosis, a severe weakening of the bones that can cause frequent fractures. Women are at particularly high risk of osteoporosis after menopause because of declining levels of the sex hormone estrogen, which normally promotes bone formation. Estrogen levels are also low during breastfeeding, yet osteoporosis and bone fractures are much rarer during this time, suggesting that something other than estrogen promotes bone growth. A hormone that is only produced during lactation During lactation, CCN3 (red) appears in the female brain in neurons adjacent to other cells, called tanycytes (cyan). Ingraham’s lab previously discovered that in female mice, but not male mice, blocking a particular estrogen receptor found in select neurons in a small area of the brain led to huge increases in bone mass. They suspected that a hormone in the blood was responsible for the super-strong bones but, at the time, could not find it – a quest that was further protracted during the worldwide pandemic. LINK
Another example of non-obvious (no one noticed them until now) yet important body functions. ME might involve such a still-unnoticed function.
