Close the blinds during sleep to protect your health

Even moderate light exposure during sleep harms heart health and increases insulin resistance.

Close the blinds, draw the curtains and turn off all the lights before bed. Exposure to even moderate ambient lighting during nighttime sleep, compared to sleeping in a dimly lit room, harms your cardiovascular function during sleep and increases your insulin resistance the following morning, reports a new Northwestern Medicine study.

There is already evidence that light exposure during daytime increases heart rate via activation of the sympathetic nervous system, which kicks your heart into high gear and heightens alertness to meet the challenges of the day.

There are sympathetic and parasympathetic nervous systems to regulate our physiology during the day and night. Sympathetic takes charge during the day and parasympathetic is supposed to at night, when it conveys restoration to the entire body.

Proceedings of the National Academy of Sciences