Type 2 diabetes: Risks increase when you don’t sleep in the dark

Falling asleep with light on could increase the risk of type 2 diabetes, according to a study from Flinders University (Australia). Published in the journal The Lancet Europethis work corroborates the results of previous research, which had demonstrated that night light can disrupt glucose metabolism.

Link between night light and type 2 diabetes

The study involved 85,000 Britons, who wore a light sensor for a week, day and night, at the start of the study. The volunteers were then monitored for eight years.

According to the results, falling asleep with a ceiling light of medium intensity increases the risk of type 2 diabetes by 39%, and it rises to 53% in the case of fairly bright fluorescent lighting. Leaving the television or a bedside lamp on could also induce an increased risk of 29%.

Night lighting may disrupt normal insulin regulation

But how can we explain the role of light in the onset of type 2 diabetes? For Andrew Phillips, first author of the publication and an expert in sleep studies at Flinders University, light would pass through the closed eyelids, which would send an alert signal to the brain, disrupting the normal regulation of insulin.

During the follow-up, the researchers noted abnormal blood sugar levels in volunteers who spent a night in a lit room. They were able to understand the role of night light by removing other risk factors for diabetes (obesity, sedentary lifestyle, etc.).

To prevent the risk of type 2 diabetes, Andrew Phillips recommended maintaining regularity in alternating between active phases (daytime) and rest phases (nighttime). However, the researcher was reassuring for people working at night. Plunging into darkness during the day can send an effective “rest” signal to the brain.