The two-phased study analyzed the sleep of 362 healthy UK school children (ages seven to nine) in relation to their blood levels of omega-3 and omega-6 long-chain polyunsaturated fatty acids (LC-PUFA).
The child participants were not chosen for sleep problems, but rather because they were struggling readers at a mainstream primary school. Previous research has shown an association between poor sleep and low blood omega-3 LC-PUFA in infants and in children and adults with behavior or learning difficulties.
This is the first study to investigate the links between sleep and fatty acid status in healthy children.
At the beginning of the study, parents filled out a sleep questionnaire, which revealed that four in 10 of the children in the study had clinical-level sleep problems, such as resistance to bedtime, anxiety about sleep and constant waking in the course of the night. Researchers then placed wrist sensors on 43 of the children with poor sleep in order to monitor their movements in bed over five nights.
“To find clinical level sleep problems in four in 10 of this general population sample is a cause for concern,” said lead author Paul Montgomery, Ph.D., of Oxford University.
“Various substances made within the body from omega-3 and omega-6 fatty acids have long been known to play key roles in the regulation of sleep. For example, lower ratios of DHA have been linked with lower levels of melatonin, and that would fit with our finding that sleep problems are greater in children with lower levels of DHA in their blood.”
The findings showed that the children put on a course of 600 mg supplements of omega-3 (algal sources) had nearly one hour (58 minutes) more sleep and seven fewer waking episodes per night compared with the children taking the corn or soybean placebo.
Higher blood levels of the long-chain omega-3 DHA (the main omega-3 fatty acid found in the brain) were significantly associated with better sleep, including less bedtime resistance, parasomnias, and total sleep disturbance.
Also, higher ratios of DHA in relation to the long-chain omega-6 fatty acid AA (arachidonic acid) were also associated with fewer sleep problems.
“Previous studies we have published showed that blood levels of omega-3 DHA in this general population sample of seven to nine-year-olds were alarmingly low overall, and this could be directly related to the children’s behavior and learning,” said co-investigator Dr. Alex Richardson of Oxford University. “Poor sleep could well help to explain some of those associations.”
“Further research is needed given the small number of children involved in the pilot study. Larger studies using objective sleep measures, such as further actigraphy using wrist sensors, are clearly warranted. However, this randomized controlled trial does suggest that children’s sleep can be improved by DHA supplements and indicates yet another benefit of higher levels of omega-3 in the diet.”
Source: University of Oxford