Scientists at Brigham and Women's Hospital in Boston (USA) have found that metabolites of omega-3 and omega-6 fatty acids can reduce daytime sleepiness, while fermented food products, on the contrary, can increase it. The results of the study were published in the journal eBioMedicine.

Daytime sleepiness has long been considered primarily a psychological disorder or a consequence of poor sleep. However, new data show that metabolites — molecules formed in the body under the influence of hormones and environmental factors, including nutrition — are involved in its development. 

The researchers analyzed 877 metabolites in blood samples from more than 6,000 participants in the Hispanic Community Health Study. Participants also completed a questionnaire that assessed the frequency of daytime sleepiness in various situations. 

As a result, seven metabolites were identified that had the greatest impact on sleepiness. Omega-3 and omega-6 fatty acids, found in fish, nuts, and egg yolks, reduced the likelihood of daytime sleepiness. On the contrary, tyramine, which is present in fermented and overripe foods, increased the risk of sleepiness, especially in men. In addition, it was found to be associated with a decrease in the quality of nighttime sleep.

The researchers also identified three additional molecules whose effects vary depending on gender. In particular, the female hormone progesterone, which regulates sleep processes and melatonin production, may play an important role in these differences.

The authors note that the results obtained will help to gain a deeper understanding of the biological mechanisms of sleep and may form the basis for new approaches to the prevention and treatment of sleep disorders in the future.