Funded by commercial fishing and marine products company Nippon Suisan Kaisha, Ltd., the research offers a first look at the beneficial effects of Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) omega‐3 fatty acids on sleep quality beyond children and young adults.
“To our knowledge, this study is the first to report that DHA/EPA improves sleep quality in middle‐ and old‐aged individuals, even at doses lower than those administered in previous studies,” the study authors stated.
“Studies on improving the quality of sleep for middle‐ and old‐aged adults, who are prone to decreased sleep quality, are expected to provide solutions for important public issues.”
Omega-3s and sleep
Given that DHA/EPA have been shown to “reduce the risk of heart disease, improve blood lipid levels and enhance cognitive function—all of which decline with age”, the researchers hypothesized that DHA/EPA may also have effects on sleep in older subjects.
They reference previous studies on the role of DHA/EPA in improving sleep efficiency by modulating melatonin release and in increasing parasympathetic nervous system activity, which regulates the body’s “rest and digest” functions.
“Sleep quality is greatly influenced by melatonin, which has a regulatory effect on circadian rhythms, including the rhythms of sleep, wakefulness and hormone secretion, and is known to decrease with age,” the study sets forth.
“DHA/EPA increases parasympathetic activity; hence, it is possible that the parasympathetic activity becomes more dominant than the sympathetic activity during sleep, contributing to improved sleep quality.”
The double‐blind, parallel‐group study randomly assigned 66 healthy Japanese males and females to either a treatment group, which received six 480 mg capsules containing 576 mg DHA and 284 mg EPA per day, or a corn oil placebo group.
Before and after the 12-week intervention, participants completed Oguri‐Shirakawa‐Azumi sleep inventory MA version (OSA‐MA) and Profile of Mood States (POMS2) questionnaires covering factors from sleepiness upon waking and sleep length to total mood disturbance. An objective sleep state test used a sleep scanner to collect breath, pulse and body movement data. Polyunsaturated fatty acid composition was measured at baseline and during week 12.
“In the DHA/EPA group, factor III (frequent dreaming) scores among the OSA‐MA scores were significantly improved compared to the placebo group,” the study concluded. “Additionally, sleep state tests revealed that sleep efficiency improved in the DHA/EPA group.”
More research welcome
In reviewing the study’s findings, Kaitlin Roke, director of scientific communication and outreach at the Global Organization for EPA and DHA Omega-3s (GOED), commented on the importance of expanding research on omega-3s and sleep.
“Ultimately, everyone is looking to improve their health, including getting more sleep and improving sleep quality,” she told NutraIngredients-USA.
“This results in many rumors about what dietary components or supplements might help sleep. Therefore, any work on the effects of EPA and DHA omega-3s from diet or supplements and their impact on sleep and sleep hygiene/sleep quality is welcomed.”
She, like the study authors, noted the possible influence of external factors during the study period including socioeconomic status, daily stress and the impact of COVID-19, but added that the well-designed study could be replicated in different population groups, age groups or at higher doses.
She suggested evaluating the results of the EPA and DHA levels from the red blood cells to determine baseline and 12-week measurements in the omega-3 index (EPA+DHA), as well as an evaluation at week 6 to determine if the changes to sleep quality were incremental as the amounts of EPA and DHA omega-3s were incorporated into the body.
“Despite minimal changes to sleep and sleep quality, it is important to remember that most important cellular changes can't be seen or felt!” she added.
Nutrients 2022, 14, 4136
“Effect of Docosahexaenoic Acid and Eicosapentaenoic Acid Supplementation on Sleep Quality in Healthy Subjects: A Randomized, Double‐Blinded, Placebo‐Controlled Trial”
Authors: Kaori Yokoi‐Shimizu et al.