A study published a few months back in Arthritis & Rheumatism concluded that men who smoke are less likely than nonsmokers to require artificial hip or knee replacement, and those who smoke the longest have the lowest risk of joint replacement surgery. In fact, the risk was a stunning 50% lower—even after factoring in the competing risk of death, which was higher with higher tobacco consumption.
The researchers focused on body weight, physical activity levels, and smoking, looking at over 11,000 men in the following age groups: 65 to 69, 70 to 74, and 75 and older. Smoking was associated with a lower risk of joint replacement, the association directly proportional to the amount of tobacco smoked in all three age groups.
So, what might be causing this observation?
Is it that smokers don’t suffer the obesity rates seen in nonsmokers? It is true that the heaviest men (those who weigh over about 195 pounds) are more than four times likely to undergo joint replacement compared to men who weigh less than 150 pounds.
Is there something in that cigarette? There is evidence that smoking may reduce the severity of degenerative joint disease (the wear-and-tear-of-cartilage arthritis most of us will suffer to some extent as we age): Laboratory research has shown an association between nicotine and the stimulation of chondrocytes—the cells that lay down cartilage within the joint.