Introduction: Variation in nicotine metabolism may be due to genetic alterations in CYP 2A6, environmental factors, and diet. The purpose of this research was to evaluate mint drink effect on nicotine metabolism as judged by nicotine/cotinine ratio in urine of Jordanian smokers.
Methods: Twenty-four Jordanian smoker volunteers were allocated randomly into two groups. They either received mint drink 3 times a day for 1 week during the mint drink period or avoided menthol-containing products and mint drink for 1 week during the off-menthol period. One group treatment sequence was mint drink, off-menthol, while the other group treatment was off-menthol, mint drink. Early morning urine samples were collected at baseline and at the end of each period. Samples were analyzed by liquid chromatography-mass spectrometry for the nicotine and cotinine concentrations. Nicotine/cotinine ratio was calculated and compared among the different periods for each participant using the paired t test.
Results: All participants showed a consistent pattern of higher nicotine/cotinine ratios during mint drink compared with off-menthol periods, although to a variable extent. Mean nicotine/cotinine ratio during mint drink for all participants (1.327 ± 0.707) was higher than that during off-menthol (0.993 ± 0.547). Paired t test statistical analysis revealed a p < .0001. The mean difference in nicotine/cotinine ratio between the two periods was (-0.335), and the 95% confidence interval of the mean difference was (-0.451) - (-0.219).
Conclusion: Mint drink increased nicotine/cotinine ratio in urine, suggesting a reduction in conversion of nicotine to cotinine.