Supplementation of long-chain omega-3s, and docosahexaenoic acid (DHA) in particular, was associated with seven fewer wake episodes and longer sleep duration—58 minutes of more sleep per night—in a subset of children, according to a new study conducted at the University of Oxford in the United Kingdom. Additionally, higher blood levels of DHA may relate to better sleep among children based on parent-rated observations.
“Fatty acids and sleep in U.K. children: Subjective and pilot objective sleep results from the DOLAB study – a randomized controlled trial," was recently published in the peer-reviewed Journal of Sleep Research. The randomized, placebo-controlled clinical trial and the observational analysis were a part of the independent study—DHA Oxford Learning and Behavior (DOLAB)—initiated at the University of Oxford and funded by a grant from DSM Nutritional Products.
Paul Montgomery, Ph.D., professor of psychosocial intervention, Centre for Evidence-Based Intervention at the University of Oxford, reported the results were broadly in line with his expectations. However, he was surprised to see "how large the change was in the objectively measured sleep—the kids slept for nearly an hour more."
Montgomery has been working in the field of sleep disorders since he did his doctorate. He also began working with Alex Richardson during that time—it wasn't long before the two began considering the connection between their two areas of work. "The early studies Alex did indicated some connection between behavior, learning, fatty acids and sleep," Montgomery commented. "So it was great to be able to carry out a robust study of this kind."
The DOLAB randomized, placebo-controlled clinical trial explored whether 16-week supplementation of 600 mg of DHA from algae per day verses corn/soybean oil placebo may improve sleep in a subset of children (n=362) aged 7 to 9 years recruited from mainstream schools in Oxfordshire, U.K., who were underperforming in reading. Additionally, the lead investigators assessed sleep patterns objectively in a random subgroup of 43 children by actigraphy (a non-invasive method of monitoring rest and activity cycles) and via sleep diaries completed by the children’s parents. The following variables were measured by actigraphy over five nights:
• Sleep onset and offset times;
• Sleep duration in minutes;
• Minutes awake between sleep onset and offset;
• Sleep efficiency (total sleep time divided by time in bed);
• Sleep latency (minutes needed to fall asleep);
• Number of wakings after sleep onset.
While the treatment trial did not show significant effects on sleep measures, as reported by the parent questionnaire (Child Sleep Habits Questionnaire – CSHQ), algal DHA supplementation did lead to an average of seven fewer wake episodes and 58 minutes of more sleep per night in the actigraphy subgroup of children.
The investigators also examined associations between blood fatty acid concentrations from fingerstick blood samples and subjective sleep using the CSHQ in a large epidemiological sample of children (n=395) participating in the DOLAB study.
Parents and caregivers were asked to rate their child’s sleep habits over a typical week on 45 items using a three-point scale. Scores from the CSHQ questionnaire indicated 40 percent of the children had clinical-level sleep problems.
Higher levels of DHA in the blood were significantly associated with better sleep, including less bedtime resistance, parasomnia and total sleep disturbance. Additionally, higher ratios of DHA and the long-chain omega-6 fatty acid arachidonic acid (ARA) were associated with less sleep disturbances.
Certainly additional research will continue to examine the connection between omega-3s and sleep patterns. The DOLAB study was of particular interest based on its use of algal DHA, as opposed to a marine source. Montgomery noted, "Algal DHA had the advantage of allowing us to encourage vegetarians to join the study, and is of course much more sustainable than DHA from other sources."
As for his next steps? "We are currently applying for a grant to look at the effect of fatty acids on insomnia in adults, which is the next obvious move for this work," Montgomery concluded. "It will be exciting to see whether the results hold up in this group!"