Blue Light Battle

Time for bed … but first, just ONE MORE TikTok video!

This is Sandra Tsing Loh with the Loh Down on Science. 

Blue light naturally comes from the sun. But modern humans have developed EXTRA exposure! Think artificial light sources like LED lights, tablets and cell phone screens! How do these affect our sleep?

Asuka Ishihara and colleagues at the University of Tsukuba in Japan had a BRIGHT idea! 

Ten volunteers stayed overnight in separate suites. First, they sat under either dim light, LED or O-LED light for four hours before bedtime. While sleeping, they wore sensors to measure their sleep patterns, body temperature and fat burn. 

Results? Exposure to any nighttime light doesn’t disrupt sleep cycles. But it DOES affect your body’s energy production and use! O-LED light lowered core body temperature by one degree celsius. Additionally, volunteers exposed to LED light did not break down as much fat while sleeping. 

So not only does obsessive doom scrolling mess with our bedtime – it can also contribute to weight gain!

Tonight’s bedtime routine? A long, engrossing book … on paper that is!! 


Reference: Ishihara, A., Park, I., Suzuki, Y., Yajima, K., Cui, H., Yanagisawa, M., Sano, T., Kido, J., & Tokuyama, K. (2021). Metabolic responses to polychromatic LED and OLED light at night. Scientific Reports, 11(1), 12402. https://doi.org/10.1038/s41598-021-91828-6