Improvements in the Subjective Sleep of Japanese Middle-aged Managers from the Consumption of an Edible Film Containing Crocetin

Abstract

It has been reported that Japanese people sleep for an average of 7 hours and 22 minutes per night, with those in their 40s and 50s sleeping the least. This is much less than in other developed countries. Aging has also been reported to decrease the total sleep time and sleep latency as well as increase wake after sleep onset (WASO). Crocetin is a carotenoid with antioxidant activity. It has been reported that 14 consecutive days of crocetin intake increases delta power during sleep and decreases WASO. However, the benefits of short-term ingestion have not been clarified. In this double-blind, randomized crossover study, we examined the effects of crocetin-containing edible films consumed for seven consecutive days on the sleep quality of healthy Japanese subjects working in management positions who were aged 45 years or older. The study participants comprised 20 subjects (12 males and 8 females; mean age 50.4 ± 4.8 years; body mass index (BMI) 22.5 ± 2.7). An electroencephalography (EEG) measuring device (InSomnograf®) was used to measure sleep objectively and a questionnaire, OSA Sleep Questionnaire MA version (OSA-MA) was used to assess sleep subjectively upon waking. The crocetin group demonstrated significantly higher values of OSA-MA Factor 3 (frequent dreaming) than the placebo group (placebo: 46.8 ± 6.9; crocetin: 49.5 ± 7.4). No differences were observed for the other four factors. No differences were observed in the sleep parameters determined with InSomnograf®. Our findings suggest a new effect of crocetin on sleep quality of frequent dreaming.