A recent research has shown that high level of nicotine in toenails could be sign of lung cancer in men. Nicotine is not a carcinogen, a substance responsible for causing cancer but higher levels of nicotine leads to higher levels of exposure to carcinogens in tobacco.

A recent study has revealed that men with high levels of nicotine in their toenails were about 3.5 times more likely to develop lung cancer compared to those who have lower levels of nicotine.

To study the impact of nicotine in toenails a research was conducted by the researcher Wael Al-Delaimy of the University of California, San Diego, and colleagues. They choose toenails for the study because they grow slowly and the nicotine level remains stable as compared to levels in salvia and urine.

The test was conducted on 33,737 men in 1986 and the participants were followed up every two years. Between 1988 and 2000, 210 men developed lung cancer. The results showed that nicotine level has helped in predicting the risk of lung cancer in men in spite of their smoking habits. The results revealed a surprising fact that 10% of men who had the highest levels of nicotine in their toenail clippings had never smoked.