The University of Colorado, Boulder, has found that a night light could disrupt a child’s sleep. The team found that lights, even when dim, impacted melatonin production.
The brain’s pineal gland produces melatonin. Melatonin is responsible for regulating the circadian rhythm, the 24-hour biological clock; thus, it alerts the body when it is time to wake up or sleep.
Night lights affected melatonin production
The production of melatonin is influenced by light. Therefore, its concentration during the day is lower than at night. Night lights can cause melatonin production as any light can make the brain think it is daytime. The light makes the body produce less melatonin at night, making it more difficult to fall asleep.
Studies have suggested that children are more sensitive to light. The reason is that they have larger eyes; thus, their lenses and pupils take more light.
According to an associate professor in integrative physiology and lead study author, Monique LeBourgeois, people need to stop thinking about children as tiny adults. This is because their bodies often respond differently to stimuli.
For instance, they are more sensitive to light, thus making their circadian rhythms more disruptive. LeBourgeois is the only researcher that has investigated the circadian rhythm of children.
How researchers conducted the study
The team gathered 36 children between 3 and 5. They evaluated them for nine days using wrist monitors to investigate their sleep patterns according to light exposure. The researchers used the initial seven days to put the children on a regular circadian rhythm. They would put them to bed at the same time every night to create a situation where their bodies produced melatonin at the same time nightly.
On day eight, they changed the children’s rooms into cave-like spaces and used black plastic to make the lights from the other rooms dim. Afterward, they collected their saliva samples every half hour. This move was to observe when melatonin production would increase.
The researchers found that melatonin production lowered by 70%-99% because of the light. They also recognized that dim light wouldn’t cause a significant change in adults, thus meaning children were more sensitive to light.
