Key Points

• Many Americans experience excessive daytime sleepiness (EDS).
• Some nutrients might help mitigate EDS by enhancing sleep quality.
• Among these nutrients are omega-6 fatty acids, which are present in nuts, seeds, and fatty fish.

Sleep issues are widespread in the United States. According to the Centers for Disease Control and Prevention (CDC), around 40% of adults report getting insufficient sleep, which involves both how long and how well they sleep. This lack of sleep can lead to serious health problems, such as heart disease, type 2 diabetes, stroke, and high blood pressure. Plus, it can negatively affect mental health, immunity, and metabolism. Not getting enough sleep often leads to feeling excessively sleepy during the day.

Given how common these sleep challenges are, researchers from the U.S. and Finland collaborated to explore why roughly 33% of U.S. adults experience excessive daytime sleepiness. They focused on metabolites, which are tiny molecules produced during metabolism, to discern any links between these and sleep quality. Their findings were published in The Lancet’s eBioMedicine.

How Was This Study Conducted?

The study involved multiple components with different analyses. Initially, researchers sourced data from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). They then conducted replication analyses based on three other studies: the Multi-Ethnic Study of Atherosclerosis (MESA), UK Biobank, and the Health2000 studies.

Replication analyses allow researchers to verify the robustness of previous findings and ensure their consistency. This step is crucial for confirming results.

The HCHS/SOL study included over 6,000 participants of Hispanic/Latino descent, all of whom provided the necessary information, including their results from the Epworth Sleepiness Scale (ESS) questionnaire. The ESS contains eight questions about the likelihood of dozing off in various situations, with scores ranging from 0 to 3 and a maximum score of 24. Scores of 11 or higher indicate EDS.

Researchers also examined participants’ bloodwork, which included measurements of metabolites linked to sleep. In addition, participants provided demographic and health information, including sleep duration, symptoms of insomnia, and diagnoses of sleep apnea. They also reported on their diets, which were assessed using the Alternative Healthy Eating Index (AHEI)-2010.

What Did This Study Find?

Approximately 15% of the HCHS/SOL participants were identified as having EDS, with a notable 58% of these being women. Researchers analyzed information on a total of 877 metabolites for each participant to determine potential relationships between metabolite levels and sleep.

Higher ESS scores correlated with lower levels of seven metabolites for both genders, plus four additional metabolites in men. Among these seven were two long-chain polyunsaturated fatty acids (PUFAs). These fatty acids are found in foods such as fatty fish, nuts, and seeds, as well as certain oils, like canola and peanut oils. Participants with higher PUFA levels reported experiencing less daytime sleepiness.

How Does This Apply to Real Life?

The researchers highlighted that these beneficial foods—fish, nuts, and seeds—are staples of the Mediterranean diet, which has consistently ranked high among various diets. This diet focuses on nutrient-rich foods, including fruits, vegetables, legumes, nuts, and fish, and is linked with several health benefits, such as a healthier brain, improved heart health, lower risk of rheumatoid arthritis, and perhaps even increased longevity.

Interested in incorporating more of these foods into your meals? Consider exploring quick salmon recipes or trying out spiced nut recipes.

Our Expert Take

This research suggests that individuals who consume more polyunsaturated fatty acids—found in fish, nuts, and seeds—may experience a lower risk of excessive daytime sleepiness due to the advantageous effects of these fats on sleep quality. Integrating more of these healthy fats into your diet could potentially lead to improved sleep at night.