A new study shows that evening light exposure in children could also have a problematic effect.
The parents of 36 pre-school aged children participated in the study. They were asked to fill out a sleep diary for their children for 7 days. This set a baseline for each child’s usual sleep habits. The children were then exposed to a bright LED light, one hour before bedtime. Their melatonin levels were measured every 20-30 minutes before and after exposure to the light.
- During the exposure to the bright LED light, the children’s melatonin levels were lowered by 69 – 98%.
- Each child was exposed to different light levels, ranging from 5-5000 lux in brightness. There was not a significant difference in results between children exposed to 40 lux (an average bedroom light’s brightness) and children exposed to 5000 lux (a significantly brighter light).
- Melatonin levels remained low for at least 50 min after the end of light exposure for the majority of the kids.
So what does it mean? Children appear to be very sensitive to bright light exposure before bedtime. Melatonin is the all important sleep promoting hormone. To see melatonin suppressed in this way indicates there could be a significant impact on sleep quality. More research is needed to dig in on this point.
For children struggling with behavioral sleep problems, limiting late night bright light exposure and keeping the home lit with warm and dim lighting at night could help them and the whole family to have a better sleep.