LAUSR

BACKGROUND Acetaldehyde is causally related to head and neck cancer. Individuals with aldehyde dehydrogenase 2 deficiency experience alcohol sensitivity and are referred to as "flushers" because of their skin-flushing response to high blood acetaldehyde levels after alcohol consumption. Acetaldehyde is produced in the oral cavity after local alcohol exposure without alcohol ingestion. However, the relationship between the oral acetaldehyde level after local alcohol exposure and alcohol sensitivity is unclear. Herein, sampling the exhaled breath, we evaluated the effect of alcohol sensitivity on the pharmacokinetics of ethanol (EtOH) and acetaldehyde in breath after mouth washing with alcohol. METHODS Twenty-eight healthy young adults were divided into flusher and nonflusher groups based on an EtOH patch test. The subjects washed their mouths for 30 seconds with 40 ml of 5% v/v alcohol, and their breath samples were collected 12 times over 20 minutes after mouth washing and rinsing with water. EtOH and acetaldehyde concentrations in all breath samples were measured using sensor gas chromatography. RESULTS Breath EtOH concentrations exponentially decreased in both groups after mouth washing with alcohol. Breath acetaldehyde concentrations showed an immediate increase, followed by an almost exponential decrease in both groups, but concentrations in the flusher group remained higher than those in the nonflusher group throughout the 20-minute measurement period. This was reflected in a peak concentration (Cmax ) of 808 ± 70 parts-per-billion (ppb) versus 1,715 ± 223 ppb, respectively (p = 0.001), and area under the curve values of 3,528 ± 1,399 ppb minutes versus 8,637 ± 1,293 ppb minutes, respectively (p = 0.002). CONCLUSIONS This study revealed high concentrations of acetaldehyde in breath after local alcohol exposure in the oral cavity among flushers even without alcohol ingestion. This contributes to an increased risk among flushers of mutagenic DNA lesions in the mucosa of the upper digestive tract and cancer.