Whether in the form of video games, phones, fluorescent lighting, computers, TVs or handheld devices, artificial light interferes with one of the most important biological processes of the human body: sleep. According to research from the Netherlands’ Leiden University Medical Center, artificial light pollution destroys sleep/wake cycles, taking a physical toll on cognition and surprisingly, musculoskeletal health.
The bombardment of artificial light that enters through the photo receptors in the eyes changes how a person’s biological clock regulates sleeping patterns. If sleep patterns are disturbed, then a person’s entire body is affected, including their ability to handle stress, to focus during the day and to handle difficult tasks. As artificial light pours through our senses late into the night, it sends conflicting messages to the brain. Research on its negative effects has never been more important.
The biological clock of the human nervous system is being polluted by artificial light
There’s a 24-hour biological clock built within the nervous system of the human body. This master clock is governed by a group of about 20,000 nerve cells in the brain called the suprachiasmatic nucleus (SCN). This organization of nerve cells is located in the hypothalamus, just above the intersection of the optic nerves that are connected to a person’s eyes.
This intricate, master biological clock is the basis for all biological clock systems within the cells of the human body. These cellular biological clocks are groupings of interacting molecules that control circadian rhythms throughout the body. While this process of regulating body cycles is internal, it is impacted by environmental factors. For example, the amount, timing and type of light wavelengths that the eyes take in ultimately communicate to the internal biological clock how to respond to its environment. Certain light wavelengths can signal some genes to be turned on or off, thus influencing a person’s internal clock. In essence, artificial light pollution can affect biological processes such as hormone release and body temperature. Abnormal circadian rhythms have also been associated with depression, obesity, diabetes, mood problems and seasonal affective disorder.
Experiment finds that artificial light weakens motor activity, physical strength
The Netherlands study looked closely at the biological clocks of rats and how artificial light affected their circadian rhythms. The control group lived under normal conditions, consisting of 12 hours of light and 12 hours of dark, while another group of rats was exposed to continuous light for six months straight. The health results differed drastically.
After six months of continuous light, the musculoskeletal systems of the rats began to break down. They measurably lost muscle strength, and started showing signs of early-stage osteoporosis. Their bodies did not recuperate as they naturally would have under normal light and dark cycles. In fact, their bodies started getting fatter, their blood glucose levels shot up and their immune system health deteriorated. As the rats’ circadian rhythms were thrown off balance by light alone, their body’s physiological processes began to break down in just months.
Chris Colwell, a psychiatry professor and sleep specialist at the University of California, who was not involved with the study, said that, “not only did motor performance go down on tests, but the muscles themselves just atrophied, and mice physically became weaker under just two months under these conditions.”
The good news in this study is that physiological processes are extremely adaptable to changes, both bad and good. Once a natural light-to-dark balance was restored to the rats’ environment they began to adjust and their health improved within two weeks. The study is the first of its kind to show markers for negative effects on the musculoskeletal system, including poor motor performances due to the disruption of circadian rhythm.
Understanding this research could implement changes in nursing home and hospital environments, which are under continuous artificial light. How does this continuous artificial light in these environments weaken the most vulnerable? This research could also direct insomniacs toward the root of their sleep problems, and encourage them to stop gazing into artificial light late into the night.