title: Dietary patterns and sleep symptoms in Japanese workers: the Furukawa Nutrition and Health Study.
abstract: OBJECTIVE
  Experimental studies have shown that some nutrients are involved in initiating and maintaining sleep, but epidemiological evidence on overall dietary patterns and insomnia is scarce. We investigated the relationship between dietary patterns and sleep symptoms in a Japanese working population.
  
  
  METHODS
  The participants were 2025 workers, aged 18-70 years, who participated in a health survey during a periodic checkup in 2012 and 2013. Dietary intake was assessed with a self-administered diet history questionnaire. Dietary patterns were extracted by principal component analysis on the basis of the energy-adjusted intake of 52 food and beverage items. Sleep duration, difficulty initiating and maintaining sleep, and poor quality of sleep were self-reported. Logistic regression was used to estimate the odds ratios of each sleep symptom according to quartile categories of each dietary pattern with adjustment for potential confounding variables.
  
  
  RESULTS
  We identified three major dietary patterns. A healthy pattern, characterized by a high intake of vegetables, mushrooms, potatoes, seaweeds, soy products, and eggs, was associated with a decreased prevalence of difficulty initiating sleep once or more a week (P for trend = 0.03); the multivariate adjusted odds ratio in the highest quartile of this score compared with the lowest was 0.75 (95% CI: 0.57-0.99). This association persisted after the exclusion of individuals with severe depressive symptoms. However, there was no significant association with difficulty initiating sleep at least three times a week.
  
  
  CONCLUSIONS
  Our findings suggest that a healthy dietary pattern may be associated with difficulty initiating sleep at least once a week.
authors.affiliation: Department of Epidemiology and Prevention, Center for Clinical Sciences, National Center for Global Health and Medicine, Tokyo, Japan. Electronic address: kkurotani@ri.ncgm.go.jp.
authors.forename: Kayo
authors.initials: K
authors.lastname: Kurotani
authors.affiliation: Department of Health Administration, Furukawa Electric Corporation, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kochi
authors.affiliation: Department of Epidemiology and Prevention, Center for Clinical Sciences, National Center for Global Health and Medicine, Tokyo, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Nanri
authors.affiliation: Department of Health Administration, Furukawa Electric Corporation, Tokyo, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Eguchi
authors.affiliation: Department of Epidemiology and Prevention, Center for Clinical Sciences, National Center for Global Health and Medicine, Tokyo, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kuwahara
authors.affiliation: Department of Health Administration, Furukawa Electric Corporation, Tokyo, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Tsuruoka
authors.affiliation: Department of Epidemiology and Prevention, Center for Clinical Sciences, National Center for Global Health and Medicine, Tokyo, Japan.
authors.forename: Shamima
authors.initials: S
authors.lastname: Akter
authors.affiliation: Department of Health Administration, Furukawa Electric Corporation, Tokyo, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Ito
authors.affiliation: Department of Epidemiology, Faculty of Public Health, Thai Nguyen University of Medicine and Pharmacy, Thai Nguyen Province, Vietnam.
authors.forename: Ngoc Minh
authors.initials: NM
authors.lastname: Pham
authors.affiliation: Department of Epidemiology and Prevention, Center for Clinical Sciences, National Center for Global Health and Medicine, Tokyo, Japan; Department of Health Administration, Furukawa Electric Corporation, Tokyo, Japan.
authors.forename: Isamu
authors.initials: I
authors.lastname: Kabe
authors.affiliation: Department of Epidemiology and Prevention, Center for Clinical Sciences, National Center for Global Health and Medicine, Tokyo, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Mizoue
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004032:Diet / Q000009:adverse effects; D004531:Eggs; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000209:etiology; D007319:Sleep Initiation and Maintenance Disorders / Q000209:etiology; D045730:Soy Foods; D014675:Vegetables; D055815:Young Adult
keywords: Dietary pattern; Difficulty initiating sleep; Difficulty maintaining sleep; Insomnia; Poor quality of sleep; Short sleep duration