This hormone strengthens bones in women and prevents osteoporosis.

Scientists have solved a long-standing mystery about how breastfeeding women’s bones remain strong despite the loss of calcium in their milk. The discovery could have important implications for the treatment of osteoporosis, a disease that affects not only 200 million people worldwideespecially postmenopausal women.

A team led by Holly Ingram found that HCM plays a critical role in bone health.If we had not studied female mice, we might have missed this discovery.” says Ingram, stressing the importance of including both male and female animals in the study.

During breastfeeding, estrogen levels are low, which would predispose women to osteoporosis. However, this does not happen, prompting researchers to look for another factor that promotes bone formation. In female mice Blocking the Estrogen Receptor in Certain Neurons Increases Bone Masswhich suggests the existence of an unknown hormone, now called HCM.

In experiments with young and old adult mice, both female and male, HCM dramatically increased bone mass and strength within a few weeks. In estrogen-depleted female mice or very old female mice, HCM doubled bone mass. The authors highlight the remarkable resistance of HCM-treated bones, indicating the revolutionary potential of this hormone.

The researchers also developed hydrogel patch which releases HCM at the site of bone fractures, promoting new bone formation and speeding up healing. This method has shown promising results, especially in older mice, which are typically poor at healing fractures.

The team plans to study the molecular mechanisms of HCM, its presence in lactating women, and its potential for treating various bone diseases.

“Bone loss affects not only postmenopausal women, but also breast cancer survivors, young elite athletes, and older men with lower survival rates after hip fractures,” explains Ingram. “HCM may offer new hope for these groups.”

This discovery represents a significant advance in the understanding and treatment of bone diseases, opening up new possibilities for more effective and specific treatments.