Sometimes losing weight can be difficult, no matter how healthy your diet is. But before you blame yourself, there’s another culprit that may be robbing your body of its natural ability to burn fat while you sleep: your LED light bulb. Exposure to blue light in the hours before bed disrupts the body’s natural metabolism of fat, a new study out of Japan has found, and LED lamps emit blue light.
Screens like your phone or TV in the bedroom emit good blue light. Blue light disrupts your sleep patterns and your melatonin production, which helps your body burn fat when it’s working well while you sleep. The implication is that we have largely sabotaged our sleep patterns and natural fat burning process. LEDs have gained popularity over the past decade for their energy savings, and most Americans we know watch TV in the hours before bed.
That LED lamp in the bedroom? Plus the blue light from your computer? Your cell phone under the pillow? They all emit blue light, which can disrupt your body’s natural metabolism of fat, according to a new study showing blue light at night can be harmful to your metabolism. The assumption is that if we all stopped exposing ourselves to blue light in the hours before bed, we could lose weight while we slept.
The study finds that “blue light at night” is linked to weight gain, and that LEDs in the bedroom and blue light-emitting screens before bed make it harder for you, me, and all of us to shed the weight we’re trying to to lose. The study authors from the University of Tsukuba have published their results in a article in Research News Journal entitled: “Turn Off the Blue Light!”
They concluded that “Light with less blue before sleep is better for energy metabolism”. In particular, they found that LED lights in the hours leading up to bedtime cause changes in melatonin that are linked to the body’s fat oxidation process during sleep.
Night lighting: how does blue light affect sleep?
The researchers studied light-emitting diodes (LEDs), which emit blue light, compared to organic light-emitting diodes (OLEDs). According to the study, LEDs emit a large amount of blue light, which has been linked to negative health effects, including metabolic health. OLEDs emit white light that doesn’t seem to affect metabolism during sleep, which the Tsukuba University researchers wanted to address.
According to the study, LEDs emit a large amount of blue light, which has been linked to negative health effects, including metabolic health. OLEDs emit white light that doesn’t seem to affect metabolism during sleep, which the Tsukuba University researchers wanted to address.
“Energy metabolism is an important physiological process that is altered by exposure to light,” says lead author of the study, Professor Kumpei Tokuyama. “We hypothesized that OLED exposure would have less of an effect on sleep architecture and energy metabolism, similar to low light, compared to LEDs.”
The study exposed 10 male participants to either LED, OLED, or low-level light for four hours before bed and measured their energy output, core body temperature, fat oxidation, and melatonin levels while they slept. ‘The results confirmed part of our hypothesis,’ explained Professor Tokuyama. “Energy expenditure and core body temperature during sleep were significantly reduced after OLED exposure. Also, fat oxidation during sleep was significantly lower after LED exposure compared to OLED.”
Fat oxidation (or burning) during sleep was positively correlated with melatonin levels after OLED exposure, suggesting that the effect of melatonin activity on energy metabolism varies with the type of light exposure.
“Hence, nocturnal light exposure is related to fat oxidation and body temperature during sleep. Our results suggest that certain types of light exposure can affect weight gain, along with other physiological changes,” says Professor Tokuyama.
Exposure to artificial lights before sleep can affect your body’s natural ability to burn fat during sleep. This is just one of many benefits of cutting off artificial lights before bed: Studies have shown that going to bed early can reduce depression, and minimizing light intake can help you sleep earlier.
Bottom Line: Reduce blue light as part of your sleep ritual
Exposure to blue light during the night can mess up your metabolism. Try switching your LED lights to OLED lights in the bedroom, or stay away from blue light in the form of screens, phones, computers, and tablets in the hours before bed. The negative effects of light exposure before bed are just being discovered, so until further research is done, choose organic light sources before bed.
Looking for more ways to improve your sleep and overall health? Read more about what to eat before bed to sleep better.