Toenails hold clue to lung health

A new study found that your toenails may hold clues to your risk of developing lung cancer.

Men with high levels of nicotine in their toenails were about 3.5 times more likely to develop lung cancer than those with lower levels of nicotine, regardless of their smoking histories.

What's different about this study is that it suggests the long-lasting effect of smoking may be underestimated in studies that rely on only self-reported smoking histories to assess lung cancer risk, the researchers said. Also University of California-San Diego researchers suggest that because toenails grow slowly, nicotine levels in them are relatively stable compared to levels in urine or saliva.

The study, which involved 33,737 men and began in 1986, was published online March 2 in the American Journal of Epidemiology. Two studies released last week highlighted the risks and benefits of lifestyle choices in combating cancer, showing the dangers of smoking for post-menopausal women and exercise's protective effect on the bowel.

Post-menopausal women who smoke, or who used to smoke, face an up to 16-percent higher risk of developing breast cancer compared to women who have never smoked, according to a paper published online by the British Medical Journal