In a groundbreaking study, researchers from Uppsala University in Sweden have discovered that just three nights of poor or limited sleep—restricted to four hours—can lead to changes in the blood associated with a higher risk of developing heart disease.
To reach this conclusion, the scientists examined inflammatory proteins in the blood that the body produces when under stress or fighting illness. If these protein levels remain elevated for an extended period, they can damage blood vessels and increase the risk of issues such as heart failure, coronary artery disease, and atrial fibrillation (irregular heartbeat).
What Did the Scientists Find?
The team involved 16 healthy young men in their study. They spent several days in a controlled laboratory environment where researchers meticulously monitored their diet, activity levels, light exposure, and other factors. During the experiment, the volunteers followed two sleep patterns: three nights of normal sleep (8.5 hours) and three nights of restricted sleep (4.25 hours). After each sleep phase, the men performed a short high-intensity workout on a stationary bike. At each observation stage, the scientists analyzed the participants’ blood, as reported by Science Alert.
Overall, the researchers measured about 90 different proteins in the blood samples. They found that sleep deprivation led to a significant increase in inflammatory markers linked to heart disease.
As the scientists noted, physical exercise typically boosts levels of beneficial proteins like interleukin-6 and BDNF, which support brain and heart health. However, after poor sleep, this support was diminished.
Even Young Hearts Are Not Immune
Surprisingly, these changes affected even young, healthy men who were deprived of quality sleep. According to the researchers, this is a cause for concern, especially considering that many adults frequently complain about insufficient or restless sleep. Moreover, nearly one in four people work shifts, disrupting their sleep patterns.
The researchers also found that the time of day when blood was drawn from the volunteers was crucial. Protein levels were unstable in the morning and evening, but they fluctuated the most when participants were sleep-deprived. This indicates that sleep not only affects what is in our blood but also when the changes are most pronounced.
Modern life often pushes us to sacrifice quality nighttime rest for various reasons. This study serves as a reminder that these sacrifices do not go unnoticed by our bodies.