Objectives: Nearly 9 million Americans use prescription sleep aids to induce or maintain sleep; however, the long-term effects of these medications are unknown. Considering the number of individuals reporting insufficient sleep, nonpharmacologic methods for improving sleep are needed.
Design: A systematic review of published studies was conducted to determine the efficacy of nutritional intake as a modality for improving sleep behavior. Inclusion criteria for the review were interventions (both in vivo and in natura), using any quantitative design, employing a dietary intervention as the primary treatment variable, targeting sleep behavior, in nonclinical human populations age 18-50 years.
Results: A total of 21 studies (17 in vivo and 4 in natura) met the inclusion criteria and were included in the systematic review.
Conclusions: The evidence for nutrition as treatment modality for improving sleep is mixed. Nearly half of the in vivo trials suggested a significant change in a primary sleep variable of interest. However, a majority of these trials relied on small sample sizes of healthy sleepers and manipulated nutrition in an acute fashion. Among the in natura studies, macronutrient composition appeared to have no effect. However, the small number of studies mainly recruited healthy sleepers, and most had limited control of the diet of participants.