A new study from the United States shows that light during sleep may impair cardiovascular and glucose regulation, thereby increasing the risk of cardiovascular disease, diabetes, and metabolic syndrome.
Evanston, IL (Merxwire) – Many literature and studies have shown that sleeping with the lights on have adverse effects on the human body, and sleeping with the lights on may increase the risk of depression, vision damage, and cancer. Scientists have discovered that sleeping with the lights on even impair cardiometabolic function.
According to research from Northwestern University, receiving moderate light (100 lx) at night during sleep increases nighttime heart rate, decreases heart rate variability (higher sympathovagal balance), and increases insulin resistance the next morning. The study was published in the Proceedings of the National Academy of Sciences (PNAS).
The researchers recruited 20 adults to participate in the experiment for three days and two nights and recorded their conditions through activity recorders and sleep diaries. Participants were randomly assigned to two groups, one of which slept in dim light on both nights (<3 lx); the other, who slept in dim light on the first night (<3 lx), The second night slept in an indoor overhead light environment with moderate light (100 lx).
The research team found that exposure to moderate light resulted in higher heart rate during sleep, reduced heart rate variability, and adversely affected glucose homeostasis the next morning compared to dim light conditions. On the other hand, participants were exposed to moderate light during sleep, had more light sleep (stage N2), and had fewer slow waves.
Because decreased heart rate variability (higher sympathovagal balance) leads to insulin resistance the next morning, experimental results suggest that one-night exposure to room light during sleep may impair glucose homeostasis by activating the sympathetic nervous system (SNS). Avoiding light exposure during nighttime sleep may benefit cardiometabolic health.
According to experimental results, exposure to moderate light during a night of sleep impairs blood sugar and cardiovascular regulation and increases risk factors for heart disease, diabetes, and metabolic syndrome. Although the study is only three days and two nights, these diseases will not occur overnight, but the study results remind people not to sleep with the lights on in the long term.
If you think these diseases are far away from you, there is also bad news: scientists have found that sleeping with the light on is more likely to gain weight than the average person! According to a study published in JAMA Internal Medicine, women who were accustomed to sleeping with the lights on or watching TV before bed were 17% more likely to gain more than 5kg in five years.
The researchers recruited 43,722 U.S. women between 35 and 74 for a five-year study. By simulating possible light sources in various sleep environments, including no lights, small nightlights in the room, lights outside the room, lights in the room, and TVs in the room, it was finally found that these lights have a positive relationship with obesity.
From the current research, turn off the lights and go to sleep! Sleeping in a dim environment is better for your health, and don’t sleep with the TV on. Pay attention to the sleeping environment and avoid light affecting the body’s metabolic regulation function to stay away from the risk of cardiovascular disease, diabetes, metabolic syndrome, and obesity.