OMEGA-3 FATTY ACID SUPPLEMENTATION AND SLEEP

Abstract

Previous research has found omega-3 fatty acid supplementation advantageous in reducing depressive symptoms. One of the central diagnostic symptoms of depression is sleep disturbance. Accordingly, this study was designed to examine the effects of omega-3 fatty acid on self-reported insomnia. It was hypothesized that participants assigned to supplement their diet with omega-3 fatty acid would have improvements in sleep efficiency, sleep onset latency, sleep fragmentation and actual sleep time. Supplementary hypotheses examined were that omega-3 fatty acid might improve cognitive ability and sub-syndromal depressive symptoms. Participants were 27 undergraduate students reporting a variety of sleep difficulties as assessed by self report of insomnia symptoms. Participants were randomly assigned either to a treatment condition, with a daily supplement of 1500 mg omega-3 fatty acid and 30 IU of vitamin E, or a control group that received 30 IU daily of vitamin E. Sleep was monitored over a 28 day period, the last 21 days of which participants were instructed to take the assigned supplements. Participants were measured on objective (Actigraph) and subjective self-report measures of sleep for seven days prior to the intervention, and during the last seven days of the intervention. They also completed a self-report screen for depressive symptoms and several cognitive tasks immediately prior to and following the intervention. A 2x2 mixed factoral analysis of variance was performed on all outcome variables. The treatment group did not improve significantly more than the control group on any measures of sleep, or mood. One cognitive measure of processing speed did significantly improve for the treatment condition. These findings are discussed in light of study limitations and the existing literature, and recommendations made for additional research focused on the possibility of sleep improvements with omega-3 supplementation in a clinically depressed population.