Research from Uppsala University in Sweden suggests that even one sleepless night could result in a loss of brain tissue.

The research, which was published in the journal SLEEP and funded by the Swedish Brain Foundation and Novo Nordisk Foundation, found a higher blood concentration of the molecules NSE and S-100B in young, sleep-deprived men compared to individuals who get enough nightly rest. According to researchers, these two molecules are typically found in the brain, but finding high concentrations of each after sleep loss indicates that a lack of sleep could be conducive to a loss of brain tissue.

Researchers tested 15 healthy, normal-weight men in their early 20s. The study participants were selected based on their ability to keep typical sleep patterns in their regular routines, which includes getting roughly eight hours of sleep per night with no more than two hours day-to-day variability in their sleep duration.

According to Uppsala, in one condition of the experiment, the men were deprived of sleep for one night. The following morning the researchers examined their blood. In another condition, the men were allowed to sleep approximately eight hours before the blood test.

“We observed that a night of total sleep loss was followed by increased blood concentrations of NSE and S-100B. These brain molecules typically rise in blood under conditions of brain damage,” said Christian Benedict, the leader of the study and sleep researcher at Uppsala University’s Department of Neuroscience. “Thus, our results indicate that a lack of sleep may promote neurodegenerative processes.”