Impact of eggplant consumption on urine cotinine examination results

Abstract

Background and Objective: A urinary cotinine test is performed to assess the smoking status. Cotinine is a nicotinic metabolite. However, foodstuffs from the plant family Solanaceae, such as eggplant, contain trace amounts of nicotine, which may have affected the cotinine test results. This study investigated the impact of eggplant consumption on urine cotinine concentration tests. Methods: Six young women who were healthy and non-smokers consumed meals devoid of Solanaceous ingredients for three days before consuming 300 grams of eggplant. After eating eggplants, the participants did not consume Solanaceous food throughout the study. During the study, participants’ urine cotinine concentrations were sampled periodically using a urine nicotine and cotinine test kit. Results: Four participants’ urine tested positive for cotinine, whereas that of two participants tested negative. The time when a positive result was recorded after consuming eggplants varied among the individuals. Participants’ urine cotinine concentrations differed as well. Conclusions: Urine cotinine concentrations may increase after consuming Solanaceous foods, even in non-smokers. When assessing the smoking status, the influence of Solanaceous foods should be considered when measuring urine cotinine levels.