Sleeping With the Light on Increases the Risk of Diabetes: When to Turn off Your Smartphone

An international research team has determined that exposure to nighttime light can significantly increase the risk of type 2 diabetes.

You've probably heard that you shouldn't be exposed to artificial light before going to sleep, especially from your smartphone, laptop, or TV. The best-known explanation is that it disrupts circadian rhythms, the body's clock that regulates various functions and hormonal changes during the day. Well, a new study has shown that this type of lighting is much more harmful, as it increases the risk of type 2 diabetes.

The experiments found that those exposed to the brightest lights at night had a nearly 70% higher risk of developing type 2 diabetes than those who slept in the dark. According to experts, the disruption of circadian rhythms may be associated with lower glucose tolerance and abnormal production of insulin, the hormone synthesized by the islets of Langerhans in the pancreas whose main function is to regulate blood sugar. This hormonal imbalance can lead to long-term health issues, including the development of chronic conditions such as diabetes.

The international research team, led by Australian scientists from Monash University's Turner Institute for Brain and Mental Health and the Flinders Health and Medical Research Institute (Sleep Health) at Flinders University, came to this conclusion after analyzing data from around 85,000 British citizens over eight years. When they compared this data with data on nighttime light exposure, they found that those who slept with the brightest lights on had a 67% higher risk of diabetes than those who slept in the dark.

These studies suggest that the body's inability to properly process glucose when exposed to light at night can have a cascading effect on overall health. Avoiding artificial light at night could be key to preventing diabetes, especially in people with a genetic tendency to develop it. It is not just about the light from electronic devices but also from other sources, such as streetlights or indoor lighting. Simply put, when you go to sleep, you should turn off all the lights – including your mobile phone – and lower the blinds, especially if you live in a city.

In addition to diabetes, excessive exposure to artificial light at night has been associated with other health problems, including sleep disorders, obesity, and cardiovascular diseases. Reducing nighttime light exposure can therefore be a simple yet effective strategy for improving overall health and well-being.