A study looks at the relationship between artificial nighttime light and the use of sleeping pills, addressing how light pollution can lead to insomnia in older adults.

Light pollution is an ever-expanding problem as our civilizations develop and make use of artificial nighttime lights. The excessive use of these lights has recently come under scrutiny by scientists as a potential contributor to negative health effects. Some studies have shown that artificial nighttime lighting can disrupt our sleep cycles, which can have downstream effects on a wide range of health conditions such as cancer, depression, and diabetes.

Other studies have shown the importance of light exposure in affect sleep habits in humans and animals. Notably, a recent American study linked outdoor nighttime lights with altered sleep behavior. A group from South Korea explored the association between residential outdoor artificial nighttime light and sleeping pill prescriptions as a more direct measure of sleeplessness. This group recently published their findings in the Journal of Clinical Sleep Medicine.

More artificial nighttime light correlates with sleeping pill prescriptions

The study utilized health data from a random sample of South Koreans aged 60+ all across the country, through their national social health insurance program. From this sample, 52027 older adults met the study’s eligibility criteria of having health data collected over a period of 12 years. Around 23% of these patients took hypnotic drugs, more commonly known as sleeping pills, and this population tended to be older, female, in the highest household income bracket or living in a metropolitan area.

Using satellite data, scientists were able to measure and quantify the amount of outdoor artificial nighttime light in different residential districts across the country. There was a clear correlation between living in areas with greater exposure to nighttime light and more sleeping pill prescriptions, after accounting for many factors including the type of residential area. Moreover, the researchers found that older adults who lived in areas with more artificial nighttime light were more likely to have higher doses of sleeping pills or use them for longer periods of time.

Light pollution can lead to sleep problems and insomnia in older adults

The data presented in this study strongly supports the idea that light pollution can lead to sleep problems and even insomnia in older adults. Using national health data and satellite images over a period of 12 years, the authors of this study were able to confirm the relationship between nighttime light pollution and sleeping pill prescriptions in older adults. The findings support other studies around the world that increasingly attribute negative effects on sleep habits to light exposure. Further investigation of the adverse effects of artificial nighttime light may reinforce policies that reduce light pollution in the hopes of improving our sleep and overall health.

Written by Branson Chen, BHSc

Reference: Min JY, Min KB. Outdoor Artificial Nighttime Light and Use of Hypnotic Medications in Older Adults: A Population-Based Cohort Study. Journal of Clinical Sleep Medicine. 2018 Nov 15;14(11):1903-10.