"The scientists studied 262 healthy girls ages 11 to 19, using questionnaires and interviews to assess their smoking habits. The researchers also measured the girls' bone density at the hip and lumbar spine three times at one-year intervals.
Smokers entered adolescence with the same lumbar and hip bone density as nonsmokers, but by age 19, they were about a year behind on average. After adjusting for other factors that affect bone health — height, weight, hormonal contraceptive use and more — the researchers found that even relatively low or irregular rates of smoking were independently associated with lower bone density."
Image: Teen girl smoking, via Shutterstock