How does exposure to outdoor artificial light at night impact metabolic health? We know that artificial light from phones and technology at night can disrupt sleep, which may increase the risk for metabolic disorders. However, what about the impact of residential or outdoor lights at night? New research suggests that these may also have an impact on the risk for diabetes.

Study Summary

This study, which included 98,658 adults in China, found that:

• Those who were in the highest quintile of exposure to artificial light at night, had a 28% higher prevalence of diabetes, when compared to those with the lowest exposure (bottom quintile). 
• Chronic exposure to artificial light at night was associated with higher levels of blood glucose, insulin resistance and diabetes. 

The researchers believe that cases of diabetes could be prevented by regulating exposure to artificial light at night. 

The Hearty Take

We know that the body runs on a roughly 24-hour day-night cycle called the circadian clock. This system relies on the natural sequence of light over the 24 hour cycle. Disruptions to this rhythm likely disrupt metabolic health. Avoid lights at night, whether from a street light or your phone. Remember, correlation does not mean causation; More research is needed to determine if improper light exposure is a cause of diabetes.