Studies of n-3 PUFA deficiency in experimental animals have shown a number of mechanisms by which DHA could specifically affect sleep regulation, including dysfunction of the superchiasmatic nuclei, altered melatonin release, and disruption of endocannabinoid signaling. In humans, higher maternal DHA levels appear to be associated with more mature sleep patterns in infants, while lower DHA levels have been negatively associated with parental ratings of sleep disorders in children.
Results of an exploratory pilot study in children (n = 43, age 7–9 years) showed that supplementation with DHA could improve objectively measured sleep. However, none of the studies assessed the effects of EPA, which might also be relevant given the previously observed effects of n-3 PUFAs on serotonin release and the production of prostaglandins, which are known to mediate the sleep / wake cycle .
The present study examined the effects of a 26-week supplementation with DHA or EPA-rich oils on subjective and objective sleep quality in 84 healthy, adult, low-consumption fatty fish using a randomized, placebo-controlled, double-blind parallel group design.
The results suggest a beneficial role for n -3 PUFAs, particularly DHA, in sleep. Benefits include an overall increase in sleep efficiency and a reduction in sleep latency, although these positive objective measures did not match subjective ratings for DHA-rich oil.
The report states, “This study was the first to demonstrate some beneficial effects of supplementation with n-3 PUFAs in healthy adult normal sleepers, and provides novel evidence of the different effects of n-3 PUFA supplements that are either rich in DHA or EPA. ”.
Participants were randomly given one of three treatments for 26 weeks (placebo, DHA-rich oil, EPA-rich oil, Accelon brand, provided by BASF).
Prior to baseline and week 26 assessment, participants were required to visit the Northumbria University Brain, Performance, and Nutrition Research Center to collect an Actiwatch, sleep diary, and urine sample pack. Participants were required to wear the Actiwatch and complete the sleep diary for the 7 nights prior to baseline and week 26 assessments and provide urine samples the evening before and morning of baseline and week 26 assessments. Participants were asked to avoid alcohol and take no over-the-counter medications for 24 hours and caffeine for 18 hours prior to the baseline and week 26 assessment.
Participants also contacted the center at week 13 to complete the Leeds Sleep Evaluation Questionnaire (LSEQ) and subjective awakening scales.
Mechanisms of Action
The observed results suggest that supplementing with DHA-rich oil resulted in a significant increase in sleep efficiency and a significant decrease in sleep latency compared to placebo in healthy adults who do not ordinarily consume oily fish.
However, the report notes that despite these improvements in objective sleep measures for actigraphy, the DHA-rich group also found that this group felt less rested and less energetic and motivated than those receiving EPA compared to placebo – Oil was administered abundantly.
The results also suggest specific roles for DHA and EPA in sleep. The report states: “The shortened sleep times found in the current study after the EPA-rich oil compared to the DHA-rich oil could possibly be explained by the role of EPA, which in turn inhibits the formation of E2-series prostaglandins the release of serotonin.
“Since serotonin promotes alertness and inhibits REM sleep, elevated circulating EPA levels may indirectly upregulate alertness promotion, resulting in reduced sleep time. It should be noted that while participants in the EPA-rich oil group reported the shortest sleep times, this did not appear to result in a decrease in sleep quality.
“Indeed, a trend towards a significant increase in sleep efficiency compared to placebo was observed, along with no increase in waking time, number of awakenings, or a decrease in ratings of subjective sleep quality. This could potentially suggest that EPA is beneficial for regulating a healthy sleep cycle and could help protect against suboptimal sleep. Further research is needed into the relationship between n-3 PUFAs and the serotonin / melatonin pathway, as well as the effects on sleep architecture. “
Jackson. PA et al
“Different Effects of DHA- and EPA-Rich Oils on Sleep in Healthy Young Adults: A Randomized Controlled Trial”