About 22.8% of adults in South Korea suffer from insomnia, with light pollution and aging being the main causes. In order to prevent and solve insomnia, measures such as reducing light pollution and managing physical changes due to aging are necessary.
According to a survey by the Korean Sleep Research Association, 22.8% of Korean adults suffer from nighttime sleep disorders, or insomnia. This means that a significant number of people are experiencing discomfort in their daily lives due to insomnia, and the number of insomnia sufferers continues to increase. According to the Korea Health Insurance Review and Evaluation Service, the number of people who have been diagnosed with insomnia has increased significantly every year. The causes of insomnia vary widely, including stress, depression, pain conditions, age, and lifestyle, but since insomnia is one of the most common modern diseases, let’s take a look at the connection between light pollution and aging.
Sleep is a physiological state of unconsciousness in which the brain periodically recovers from fatigue. Insomnia is a condition in which a person has difficulty entering or staying asleep, even when given enough time to sleep. To enter a normal sleep state, we need melatonin (aka sleep hormone), a hormone that regulates our circadian rhythms. However, patients who suffer from insomnia due to light pollution do not produce enough melatonin, resulting in insomnia. Melatonin is secreted by the pineal gland, an endocrine gland located on the dorsal surface of the brain. The pineal gland senses light entering through the skin of the head and recognizes photoperiods, such as the difference between night and day or seasonal changes in sunlight hours. When the pineal gland is activated, it releases melatonin, which induces sleep.
In the morning, a pigment called melanopsin in the eye absorbs light and activates a region close to the pineal gland called the suprachiasmatic nucleus. The suprachiasmatic nucleus is made up of about 10,000 nerve cells, and when activated, it directly inhibits the pineal gland, stopping the release of melatonin and preparing the body for activity. Conversely, when the amount of light entering the eyes decreases in the evening, the suprachiasmatic nucleus is deactivated and melatonin is released from the inhibited pineal gland to induce sleep. This sleep-inducing melatonin is usually most active between 11 p.m. and 5 a.m., allowing us to sleep at night.
However, modern people don’t get enough sunlight during the day and are exposed to artificial light, such as electronics, at night. This is because most of our work is done on computers and we use electronic devices like smartphones outside of work hours. In one survey, 54.4% of people said they had less leisure time due to smartphone use, and 51.6% said they got less sleep.
Melatonin secretion can be suppressed by as little as 10 lux of light. Therefore, modern people who are exposed to even weak light from electronic devices throughout the day may not be able to function normally with their biological clocks regulated by melatonin.
In addition to personal lifestyle habits, South Korea’s severe light pollution is also a problem. Light pollution is the excessive use of artificial light that makes it as bright at night as it is during the day. An international team of researchers from Italy, Germany, the United States, and Israel analyzed satellite images of the Earth and found that South Korea has the second worst light pollution among G20 countries.
Now, let’s look at the connection between aging and insomnia. It’s been said that as we age, we lose sleep. In fact, according to the Centers for Disease Control and Prevention, 50% of older adults suffer from insomnia. There are many reasons for this, the first of which is that as we age, our body’s organs deteriorate. Metabolic processes involving hormones also change, the most important of which is the decrease in melatonin secretion. Melatonin production peaks between the ages of 5 and 10 and then declines during puberty, and older people produce less melatonin, which can lead to difficulty sleeping. In addition, the circadian rhythm is shifted forward, causing melatonin to end earlier, resulting in less early morning sleep.
Another cause is the various diseases that accompany aging. People often suffer from physical ailments of the cardiovascular, respiratory, and digestive systems, and the medications they take can cause insomnia. In addition, chronic pain or itching caused by the disease itself can be a major factor in keeping you awake, especially at night. Sleep apnea, which is common in the elderly, is another cause of insomnia. As we age, the muscles around our airways lose their elasticity and tone, causing our airways to narrow easily during sleep, making it difficult to breathe, causing us to fall asleep deeply and wake up frequently.
Getting a good night’s sleep at the right time is essential for an energized daily life. Insomnia can make you feel foggy, heavy, and tired on a daily basis, so it’s important that we don’t take insomnia lightly as a common disease and take appropriate measures to combat it, both on a personal and societal level.
When it comes to light pollution, Korea ranks second in the world for light pollution, but despite the seriousness of the problem, there has been little effort to actually solve the problem. Unlike Australia and Canada, which have been addressing light pollution since the 1990s, South Korea did not enact its first law to reduce light pollution until 2013. Furthermore, citizens rarely report inconveniences caused by light pollution to local governments. As a result, local governments have not enforced light pollution laws, nor do they have the necessary light pollution detection equipment to do so. Recently, a video ACE system has been developed that can accurately measure light pollution, so it is necessary for organizations in charge of enforcing light pollution to be equipped with the appropriate equipment and start enforcing light pollution. They should also take a page out of other countries’ playbooks and work to make citizens aware of the problem and empower them to reduce it themselves. In San Diego County, for example, guidelines illustrate how much unnecessary light can be reduced by the height and angle of lights mounted on building walls, and also specify the types of light fixtures that are effective in reducing light pollution.
While it’s impossible to completely avoid the physical changes that come with aging, such as decreased hormone secretion, frequent illnesses, and decreased muscle tone, it’s important to maintain your physical age by taking care of your health. Aerobic and strength training exercises increase growth hormone, which is a hormone that is in short supply. Growth hormone is responsible for increasing skin and muscle elasticity, as well as boosting immunity, so it”s beneficial to do these exercises regularly.
