There is controversy spanning evidence both for and against the role that omega-3 and omega-6 intakes might play in sleep quality, including the risk of developing sleep disorders and sleep quality/duration. In a recent study, researchers sought to evaluate the impact of consumption of omega-3s and omega-6s, respectively, as well as the impact of omega-6:omega-3 ratios, on the impact of sleep duration and the risk of developing sleep disorders.
 
“The normal sleep process is affected by multiple factors with aging, manifesting as reduced sleep efficiency, increased sleep latency, and decreased deep slow-wave sleep. These symptoms may also differ by sex,” the authors said.  “Although the parameters of sleep measurement were different, several studies indicated that a higher omega-3 fatty acids level was related to better sleep. However, some studies did not find this positive association. Few studies have investigated the association between omega-6 fatty acids and sleep, and the results were inconsistent.”
 
Through a large-scale cross-sectional analysis of NHANES data collected from 2007-2016 the authors of the study found that those who consumed higher amounts of omega-6 fatty acids, and had greater omega-6:omega-3 ratios, were more likely to self-report sleep disorders and abnormally short sleep duration. In addition, omega-3 fatty acid consumption alone was linked to normal sleep duration exclusively in men. Men who consumed higher amounts of omega-3s were more likely to self-report normal sleep duration, and were at a reduced risk of very short, short, and long sleep durations.
 
Thus, the researchers concluded that omega-3 fatty acids, in the context of the overall prevalence of omega-6 fatty acids, were able to significantly improve sleep duration and reduce the risk of sleep disorders in the study population. There were 18,310 participants used as samples for sleep disorders, and another 21,153 used for sleep duration.
 
The authors wrote that, according to their knowledge, this was the first study to use a large and nationally representative sample to evaluate the interconnected relationships of omega-3 and omega-6 fatty acids in relation to sleep disorders and sleep duration in U.S. adults. While the mechanisms of action are unknown from the observational data, they proposed several explanations for the apparent health benefit – omega-3 fatty acids are involved in maintaining nervous system function and intracellular signaling, and might influence neuronal activity during sleep-wake functions. Additionally, higher omeaga-3 intake was associated in numerous animal studies with an increased concentration of 5-HT (an essential neurotransmitter in sleep preparation, triggering, and maintenance) in the hippocampus. The role that the omega-6:omega-3 ratio had in this study could have been its link to pro-inflammatory tendencies, the authors said.
 
Despite the substantial differences the authors observed in sleep patterns, they said that results should be taken with caution as the study was cross-sectional, sleep disorders were based on self-reported doctor diagnoses, along with sleep duration. Further, specific subtypes of sleep disorders were not accounted for in the study.