As screens increasingly become a part of night-time routines, exposure to unnatural light before bed becomes extended and habitual. Long after the switch turns off, artificial light disrupts metabolic processes during subsequent sleep and even into the next morning. Interference with sleep processes negatively affects energy level, circadian rhythm, body temperature, hormone secretion and metabolism. A recent study in Nature suggests that swapping out traditional light-emitting diode (LED) light sources to organic light-emitting diodes (OLEDs) can reduce physiological consequences.
OLEDs limit the amount of monochromatic blue light by instead emitting a white light comprised of many colors.
Rich in blue light, LED lights have harmful effects on sensitive cells in the retina, which are responsible for the production of melatonin (a sleep regulation hormone). OLEDs limit the amount of monochromatic blue light by instead emitting a white light comprised of many colors. The study compared the effects of LED, OLEDs, and dim light on metabolism during sleep. Energy metabolism was measured by monitoring fat oxidation, respiratory quotient (RQ), body temperature and melatonin levels.
In a “fasting” state, such as rest, the body breaks down fat storage for energy. Higher fat oxidation and lower respiratory quotient are associated with efficient metabolism and a decreased risk of obesity. In those that viewed LED lights, fat oxidation was significantly lower and RQ was higher during rest compared to those that viewed OLED and dim light sources. Melatonin levels, indicating a stable sleep cycle, showed a positive correlation with fat oxidation. Additionally, exposure to OLED light correlated with a decrease in core body temperature compared to LED; the effect of OLED better mimics the body’s natural drop in temperature before and during sleep.
Although they do not absolve the issues associated with long-term artificial light exposure before sleep, OLEDs lessen some of the problems that LED lights present. The prevalence of OLEDs has risen in recent years due to its simpler manufacture model, lower energy consumption, and improved image quality. However, the choice of OLED and LED lights remains a topic of debate for consumers and developers. Research on the physiological consequences of the light technology offers a new perspective to consider. This study suggests if your eyes will be glued to the screen, the lights behind the glass may be worth a second look.
