Nicotine in Toenails Used as Cancer Predictor?

| by Alex Groberman

According to a new report published online last week, the amount of nicotine in a person’s toenail could predict the possible risk of developing lung cancer.

Based on information retrieved from a large health study, researchers were able to analyze the correlation between the nicotine levels of male smokers who developed lung cancer over a 12-year span with male smokers who did not. It was noted that the male smokers who had the highest nicotine levels were as much as 3.57 times more likely to eventually get lung cancer, regardless of their smoking history, than those who didn't fit the bill.

The authors made it a point to mention that studies which merely look at smoking history for the purpose of their findings appear to be underestimating the effect of smoking on health.

Essentially, simply looking at how much people smoke does not paint the entire picture. The reason, of course, is because such information does not include how much smoke is being inhaled -- which leaves a lot of room for error and interpretation.

The reason that toenail clippings were picked as the measure of nicotine absorption is because of the way they grow slowly. Thus, they provide a more accurate measure of intake than saliva or urine.

For the purpose of this study, data of male smokers between the ages of 40 and 75 were utilized. The 210 men involved were diagnosed with lung cancer at some point between 1988 and 2000. As per the results, 20 percent of men with the highest level of toenail nicotine had 10.5 times the chance of developing lung cancer than those at the lowest level.  

Based on their research, it was concluded that:

"... the toenail nicotine biomarker was found to be a strong predictor of lung cancer independent of smoking history, suggesting that the adverse effects of cigarette smoke may be underestimated in studies based on smoking history only."

The authors of this study were: Dr Wael K Al-Delaimy, Associate Professor & Chief, Division of Global Health, Family & Preventive Medicine Cancer Prevention & Control Program at the University of California San Diego (UCSD) Medical Center and Dr Walter C Willett, Fredrick John Stare Professor of Epidemiology and Nutrition Chair Department of Nutrition, Harvard School of Public Health, in Boston, Massachusetts. The study itself appeared in the American Journal of Epidemiology.

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