Health Life

Light during sleep can cause health problems

  • April 8, 2022
  • 2 min read
Light during sleep can cause health problems

Exposure to even moderate ambient lighting while sleeping at night can harm cardiovascular functions and increase insulin resistance for the following morning. That’s according to a new study from Northwestern Medicine in Illinois and was published March 14 in PNAS.

“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,” said senior study author Dr. Phyllis Zee, chief of sleep medicine at Northwestern University Feinberg School of Medicine and a Northwestern Medicine physician. “It’s important for people to avoid or minimize the amount of light exposure during sleep.”

There has already been evidence that light exposure in the daytime increases heart rates by activating the sympathetic nervous system. This system heightens alertness to face the daily challenges.

“Our results indicate that a similar effect is also present when exposure to light occurs during nighttime sleep,” Dr Zee said.

There are sympathetic and parasympathetic nervous systems that regulate our physiology, with the former taking charge during the day and the latter at night.  

The researchers found that insulin resistance can occur the morning after people slept in a lit room. Insulin resistance is when cells in the muscles, fat, and liver no longer respond well to insulin. This means that they cannot use glucose from the blood for energy. The pancreas makes more insulin to compensate and over time, your blood sugar can go up.

An older study from JAMA Internal Medicine found that a large population of healthy people who were exposed to light during sleep were more overweight and obese, according to Dr Zee.

For more information on the study, visit sciencedaily.com

Image: Quin Stevenson

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