New research has linked a chronic lack of sleep to elevated risks for poor cardiovascular health, including heart attacks and stroke, because certain biomarkers in our blood are directly influenced by the amount of sleep we get each night. The study, published in the journal Experimental Physiology, was conducted by scientists based at the University of Colorado Boulder; it finds that sleeping less than seven hours per night is associated with increased cardiovascular disease rates and a higher risk of death overall.
The elevated risks are due in part to increased inflammation, which is caused by decreasing levels of acid present in all living cells known as microRNAs, the study reports. MicroRNA play a key role in regulating heart health, as it works to suppress other genetic expressions of proteins that are known to damage vascular health. "They are like our cellular brakes, so if beneficial microRNAs are lacking, that can have a big impact on the health of the cell," said Christopher DeSouza, a professor of integrative physiology at the University of Colorado Boulder, in a press release about the study. "Why seven or eight hours seems to be the magic number is unclear."
The team arrived at their conclusion after studying 24 adults between the ages of 24 and 66—half of which were getting at least seven hours of sleep per night, with the other group only sleeping just under seven hours every night—and drawing blood samples routinely. All the adults didn't smoke or take any kind of medication, were moderately healthy, and free of previous cardiovascular issues. The researchers kept a close eye on the levels of multiple chains of microRNAs throughout the study and noted that those who slept less every night had much lower circulating levels of the essential nucleic acid in at least three distinct functions of blood cells.
DeSouza says his team will continue to research how sleep can influence our health on a cellular level, and is currently looking into whether those who don't get enough sleep can reverse the damage by changing their sleep patterns. Getting a good night's rest is tied to many health issues, including dietary habits, and previous research shows that it's important to get adequate sleep every single night. The American Heart Association recommends between seven and nine hours of sleep; yet, 40 percent of adults in the United States aren't meeting those recommendations, and the average time spent sleeping has slipped down to 6.8 hours per night over the past century, according to DeSouza. "Don't underestimate the importance of a good night's sleep," he added.