The link between cigarettes and osteoporosis and bone fractures was identified 20 years ago but how it happened was not clear.
Now a new study has found that smokers produce excessive amounts of two proteins that trigger a natural body process which breaks the bone down.
The proteins increase the production of osteoclasts which reabsorb or break down old bone.
This weakens the bone which in turn increases the risk of fractures.
Details of the study are published in the American Cancer Society’s Journal of Proteome Research