Whether you toss and turn at night or sleep soundly, exposure to light can affect the quality of your rest. That blinking on your computer might not seem like a big deal, especially if you can snooze through most alarms. However, new research shows that light exposure from any source during sleep — be it technology or a street lamp — may have a negative impact on your health. Specifically, it may increase your risk of heart disease and diabetes-related symptoms.
The Impact of Light Exposure on Sleep Quality
In a new study published in the PNAS Journal, researchers affiliated with Northwestern University wanted to know how light exposure impacts our health. So, they created a test to see how light affects sleep quality, the body’s ability to regulate sugar, melatonin levels (the sleep hormone that responds to darkness), and heart health.
The researchers recruited 20 adults to take part in the study. Of those 20, 10 participants had to sleep with dim light exposure for one night and moderate light exposure the next night. The other 10 had to sleep with dim light exposure for both nights.
The authors found that the participants’ melatonin levels didn’t change much in response to dim light or moderate light. However, the quality of sleep decreased after some of the participants slept with moderate light.
Even more interesting: Just one night of sleeping with moderate light raised the participants’ nighttime heart rate and increased insulin resistance the next morning. (In effect, the participants’ bodies had a harder time regulating sugar and insulin levels). In contrast, sleeping with dim light did not affect heart rate or insulin resistance.
“The results from this study demonstrate that just a single night of exposure to moderate room lighting during sleep can impair glucose and cardiovascular regulation, which are risk factors for heart disease, diabetes and metabolic syndrome,” senior study author Dr. Phyllis Zee, chief of sleep medicine at Northwestern University Feinberg School of Medicine said in a press release.
Limitations of the Study
The study did have some limitations. With just 20 adults participating in the research, the authors can’t be certain that the findings apply to the wider population. The participants were also on the younger side, which makes it difficult to equate these findings to the older population. More research needs to be done to further explore the negative effects of light exposure on overall health.
Still, the findings are important, as they give us inspiration to make easy changes to improve the quality of our sleep. So, shut those blinds, unplug that blinking computer or TV monitor, and if all else fails, wear an eye mask! These simple extra steps could make an enormous difference in terms of both your nightly Zzzs — and your future health. (For more sleep advice, check out these five tips.)