Abstract
In the transportation industry, it is difficult to maintain the drivers’ daily rhythm due to their work style （long driving duties and various work shifts）. Driving in a drowsy state may cause serious accidents and it is necessary to take countermeasures to prevent them. Food containing asparagus extract has been reported to adjust sleep-wake rhythm and improve alertness upon awakening. Therefore, we examined the effects of the food containing asparagus extract on sleep state, fatigue, and safe driving in taxi drivers. With the cooperation of Fuji taxi group based in Aichi Prefecture, we enrolled 76 taxi drivers as subjects and conducted a four-week intervention. The subjects were divided into two groups: an active group （with test food intake） and a control group （without test food intake）, and the sleep state, fatigue, and status of safe driving were evaluated from before intake to 4 weeks after intake. We found that, the sleep time as evaluated by St Mary’s Hospital Sleep Questionnaire increased significantly in the active group compared to the control group, and the sleepiness as evaluated by Karolinska Sleepiness Scale and the fatigue feeling as evaluated by Chalder Fatigue Scale also decreased significantly. In addition, alertness upon awakening and the frequency of sleepiness during work had improved, suggesting that the intake of the test food had a beneficial effect on the improvement of sleep quality and fatigue in taxi drivers. We objectively evaluated the status of safe driving using a drive recorder and found that the number of sudden accelerations had decreased, suggesting that improvement of sleep by taking the test food may contribute to safe driving. At present, only limited methods such as cognitive behavioral therapy can be used to improve sleep, but this result shows that food containing asparagus extract can also be used as a countermeasure. Improving sleep quality using food could serve as an alternative option for maintaining drivers’ health and for promoting management of driver health in transportation companies.
