What evidence shows these effects of smoking on the bone?
Multiple studies have shown a significant difference in the healing time of bone between groups of smokers and non-smokers. For example, a recent study looked at patients who were surgically treated for a specific wrist injury. Of these patients, 95% of the non-smokers healed completely, while only 68% of the smokers healed completely. The average time until complete healing was over 2 months longer in the smokers. Numerous other studies on patients with different injuries have shown a similar effect.
Why are bones affected by smoking?
Bones are nourished by blood much like the other organs and tissues in your body. Nutrients, minerals, and oxygen are all supplied to the bones via the blood stream. Smoking elevates the levels of nicotine in your blood and this causes the blood vessels to constrict. Nicotine constricts blood vessels approximately 25% of their normal diameter. Because of the constriction of the vessels, decreased levels of nutrients are supplied to the bones. It is thought that this is the reason for the effect on bone healing.
What does all this mean?
The effect of smoking on your health is well known to have a significant negative impact. While the effect of bone healing may not seem as important as other effects, ask anyone who is waiting for their skeleton to mend and they will tell you how important bone health can be. If you sustain an injury to your bone, including any type of fracture, it is of utmost importance that you do not smoke. Doing so will decrease your chances of recovering completely, lengthen the time you spend healing, and make it less likely that you will be satisfied with your outcome.
Chen F, "Smoking and bony union after ulna-shortening osteotomy" Am J Orthop. 2001 Jun;30(6):486-9.
Chen F, et al. "Smoking and bony union after ulna-shortening osteotomy" Am J Orthop (Belle Mead NJ). 2001 Jun;30(6):486-9.