Blood Molecules Implicated in Daytime Sleepiness Highlight Role of Diet and Hormones

Recent research from Mass General Brigham has uncovered seven specific molecules in the blood that are associated with excessive daytime sleepiness (EDS), a condition experienced by approximately one-third of Americans. EDS is linked to increased risks of serious health issues like cardiovascular diseases, obesity, and diabetes.

This groundbreaking study identifies metabolites—naturally occurring blood molecules influenced by diet and hormones—that might influence the propensity to feel excessively sleepy during the day. Using blood samples from 6,000 participants in the Hispanic Community Health Study/Study of Latinos, scientists examined 877 metabolites. They also analyzed questionnaire data regarding the frequency of dozing off in various settings, and replicated their results in the Multi-Ethnic Study of Atherosclerosis (MESA) and studies conducted in the UK and Finland.

Notably, the study found that omega-3 and omega-6 fatty acids, commonly present in Mediterranean-style diets, were associated with a lower risk of EDS. Conversely, higher levels of tyramine—a compound found in fermented and overripe foods—were linked to increased sleepiness, especially among men. Additionally, sex steroid metabolites like progesterone were connected to sleep-related processes such as melatonin production.

The researchers suggest that these findings could pave the way for new treatment strategies targeting dietary habits or developing medications to better manage EDS. Future studies may involve clinical trials to test whether dietary modifications or supplements can reduce daytime sleepiness.

"Our results indicate that both genetics and diet play vital roles in EDS," said lead researcher Dr. Tariq Faquih, a postdoctoral fellow at the Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital. "Understanding the biology behind EDS allows us to identify early signs and explore potential interventions to improve patient outcomes."

While promising, the study notes limitations, including challenges in interpreting metabolite levels and relying on questionnaires rather than sleep lab assessments. Further research is planned to explore unidentified metabolites and evaluate the impact of dietary interventions in clinical settings.

This research emphasizes the importance of diet and hormonal balance in regulating sleepiness and opens new avenues for personalized treatment options for those suffering from EDS.