Researchers from American Chemical Society found that it is not toxins in cigarette smoke that weakens bones but unusually large amounts of two proteins produced by human smokers that foster production of bone breaking osteoclasts.
The scientists analysed differences in genetic activity in bone marrow cells of smokers and non-smokers.
The study was published in ACS' Journal of Proteome Research.
Gary Guishan Xiao and colleagues from the society pointed out that previous studies had suggested toxins in cigarette smoke weakened bones by affecting the activity of osteoblasts, cells which build new bone, and osteoclasts, which resorb, or break down, old bone.
The new study discovered that human smokers produce two proteins that encourage production of bone-resorbing osteoclasts compared to non-smokers.
