Scientists at the University of Arkansas for Medical Sciences (UAMS) have identified an age-related mechanism - not a decrease of the hormone estrogen - as the primary culprit behind osteoporosis.
The research team, led by Stavros Manolagas, in the UAMS Center for Osteoporosis and Metabolic Bone Diseases, said that aging and the body's increased inability to defend against bone-damaging molecules produced through a process known as oxidative stress are most directly responsible for the bone-weakening disease - and perhaps other age-related diseases.
Researchers found that age weakens the defenses against oxidative stress.
In particular, an age-related loss of certain proteins that defend against oxidative stress increase the risk of osteoporosis.
Manolagas said conditions such as a loss of estrogen can further decrease the molecular defenses against oxidative stress.
"We feel like we have turned a page in our understanding of osteoporosis," said Manolagas.
"This emerging evidence provides a paradigm shift from the 'estrogen-centric' view of what causes osteoporosis to one in which these age-related mechanisms are the main protagonists and other changes - including the reduction of estrogen - accentuate them," Manolagas added.
The research was detailed in an article in the Feb. 3 issue of the journal Cell Metabolism.