Why You’re Always Tired: Scientists Find Seven Blood Molecules That Could Be to Blame
September 8, 2025 | Brigham and Women’s Hospital
If you often find yourself dozing off at your desk or struggling to stay awake during the day, science may finally have an explanation. A new study from Mass General Brigham has uncovered seven blood molecules that appear to drive excessive daytime sleepiness (EDS) — a condition that affects nearly one in three Americans and increases the risk of diabetes, heart disease, and obesity.
“Our study suggests diet and genetics may play an important role in EDS,” said lead author Tariq Faquih, PhD, a postdoctoral fellow at Brigham and Women’s Hospital. “As we learn what’s happening biologically, we are beginning to understand how and why EDS occurs, the early signs that someone might have it, and what we can do to help patients.”
The researchers analyzed thousands of blood samples and found that certain nutrients can make a significant difference. Omega-3 and omega-6 fatty acids — the healthy fats found in fish, nuts, and olive oil — were associated with feeling more alert. In contrast, tyramine, a compound present in fermented or overripe foods, was linked to greater drowsiness, particularly in men. Hormonal molecules like progesterone were also tied to sleep regulation, including melatonin production.
The team believes the findings could lead to new treatment options. As Faquih explained, “Conducting a clinical trial would be a big next step and could help us understand if omega-3s and omega-6s obtained from diet could help lower risk of EDS.”
