A Study of Breath Alcohol Concentration Fluctuations and Cognitive Decline Due to Low-Impact Drinking

In Japan, drunk driving is prohibited under the Road Traffic Law, and penalties are set at a breath alcohol concentration of 0.15 mg/l. However, 300 cases of drunk driving occur annually even when the breath alcohol concentration is below the standard value. This suggests that even small amounts of alcohol consumption may cause a decline in brain function. In this study, we evaluated the brain function caused by low-intensity drinking using event-related potentials, a type of electroencephalogram (EEG). The results showed that breath alcohol concentration increased significantly (p < 0.05) at 10, 30, and 50 minutes after drinking compared to before drinking. Event-related potentials during these time periods also changed significantly (p < 0.05). On the other hand, there was no significant difference in expiratory alcohol concentration during the first 70 minutes after drinking, but there was a significant change in event-related potentials. The present study suggests that low alcohol intake at low loads causes a decrease in brain function.