Dim light Disrupts Sleep, NIH Study Finds
BETHESDA, MD – Even small amounts of light exposure during sleep can negatively impact metabolic health and heart rate, according to a recent study by the U.S. National Institutes of Health (NIH). Researchers found that sleeping with dim light-from sources like LED strips, lamps, or gaps in window coverings-increased heart rate and insulin resistance in participants compared to those who slept in complete darkness.
The study involved 20 participants, split into two groups of 10. One group slept in a laboratory setting one night in complete darkness and another night with dim light, while the other group slept two consecutive nights in total darkness. Researchers observed that even minimal light exposure led to elevated heart rates and increased insulin resistance, suggesting the body wasn’t achieving full restorative rest.
Sleep is regulated by the circadian rhythm, the body’s internal clock, which is heavily influenced by light detected through the eyelids by specialized cells called ipRGCs. These cells can detect even low levels of light and impact melatonin production-the hormone crucial for sleep.
Blue light, emitted from devices like LED screens, tablets, and cell phones, is especially disruptive to melatonin production. Researchers recommend avoiding screen time for one to two hours before bed to mitigate these effects.
Individuals can assess their bedroom for unwanted light sources by turning off all lights and allowing their eyes to adjust to the dark for approximately 60 seconds. Common culprits include illuminated phone chargers, standby lights on electronics, and light leaking through window or door gaps. simple solutions like insulating tape for devices and cloths or blankets for cracks can definitely help achieve optimal darkness and possibly improve sleep quality.
