In the space of 100 years, advances in technology have had a profound effect on our health –both positive and negative. Even a seemingly benign technology like artificial lighting has proven to be hazardous to health when used to dismiss natural sleep urges.
In cases of extreme sleep deprivation, the result can be lethal. Finally, the Guinness Book of World Records discontinued reporting how long people could stay awake to discourage this extremely dangerous contest. Inevitably, the power of technology to produce benefits comes with the potential for harm unless used wisely.
In the case of artificial lighting, what seemed so incredible when first invented, has become a serious health hazard as eyeballs become increasingly fixed on smartphones, personal computers, and indoor lighting that extend the day far beyond what our health can bear.
The World Health Organization has recognized this trend and declared sleep loss due to artificial light an epidemic responsible for a host of chronic conditions. Shift work where people rarely see daylight is now considered a carcinogenic activity. In countries where sleep time has declined the most dramatically over the past 100 years, there have been significantly increased rates of mental disorders attributable to artificial lighting.
Perhaps you have noticed a desire to eat more when you are tired? This is no coincidence; too little sleep swells concentrations of a hormone that makes you feel hungry while suppressing another hormone that signals food satisfaction. It gets worse. Getting less than 6 or 7 hours of quality sleep a night significantly degrades your immune system, thereby more than doubling your risk of cancer.
The urge to sleep is determined primarily by two factors, both of which are frequently circumvented by overuse of artificial lighting technology – especially LED lights that overemphasize blue light. The first factor is a signal from a 24-hour clock located in the brain. This clock creates a cycling rhythm that makes you feel tired or alert at regular times of night and day. The second factor is adenosine, a chemical substance that builds up in your brain and creates a desire to sleep. The longer you’ve been awake, the more adenosine accumulates, and the sleepier you feel. It is largely the balance between these two factors that determines how alert you are during the day, when you will feel tired, and how well you will sleep. Typically, adenosine concentrations peak after 12 to 16 hours of being awake. At that time, an urge for slumber will take hold unless you have confused your internal clock or have taken other measures to offset the effects of the accumulating adenosine.
Although everyone has a 24-hour pattern, their peaks and troughs of alertness can be quite different. For some, their peak wakefulness is early in the day, and their sleep urge arrives by 9:00 PM. These morning types that prefer to wake up at dawn (early birds) make up about 40% of the population. In contrast, evening types (the owls) prefer to wake up later and sleep later. These owls make up about 40% of the population. The remaining 30% of people fall somewhere between these two types with a bias toward being owlish.
In adulthood, your ‘owlishnes’ or ‘early birdness’ is strongly determined by genetics. If you are an owl type, it is likely that one or both of your parents is an owl type, and likewise for being an early bird. Unfortunately, society is not kind to owls. Often owls are viewed as lazy, based on their need to wake up later in the day. In a world where many must wake for school or work before daylight, early birds tend to chastise night owls on the assumption that such preferences are a choice.
Being an owl can be a challenge in modern society when they are often forced to adapt. Owls tend to suffer more health consequences, including higher rates of cancer, heart attacks, stroke, depression, anxiety, and diabetes unless they practice good sleep hygiene as will be explained later.
Caffeine in coffee, sodas, and tea are often used to suppress the desire for sleep. However, this strategy has a downside. Caffeine has an average half-life of 5 to 7 hours. So, if you have a cup of coffee after your evening dinner, around 7:30 in the evening, 50% of that caffeine may still be circulating throughout your brain at 1:30 in the morning. Also, be aware that decaffeinated does not mean not caffeinated. One cup of decaf may contain up to 30 percent of the caffeine in a regular cup of coffee.
Based in large part on genetics, some people have a more efficient version of the liver enzyme that removes caffeine. These rare individuals can drink coffee all day and fall fast asleep at night without a problem. Others with a slower acting version of the enzyme take far longer for their system to eliminate the caffeine. For slow caffeine metabolizers, a single cup of tea or coffee in the morning can last most of the day. Should they have a second cup early in the afternoon, they may find it difficult to fall asleep at their usual bedtime. Aging also has an effect. As we get older, it takes longer to remove caffeine and adds to other sleep issues that often accompany aging.
Other than refined sugar, caffeine is the most common addictive substance routinely given to most children and teens. While most are aware that added sugar is a health issue, far fewer appreciate the negative effects of caffeine on child development. When caffeine is present, sleep quality decreases. When sleep quality decreases, IQ decreases and many health issues increase. Quite simply, no child needs caffeine.
Many believe that alcohol helps them fall asleep more easily. Some also believe alcohol gives them sounder sleep. Sleep studies show that despite the subjective impression, both beliefs are false. Granted, alcohol does provide a feeling of relaxation as it sedates the prefrontal cortex. Unfortunately, given more time, alcohol begins to sedate other parts of the brain. In essence, alcohol sedates you out of wakefulness, but not into natural sleep. The effect is that the electrical brainwave state you enter via alcohol is more like a state of anesthesia. The result being that alcohol dismantles an individual’s sleep quality in two ways.
The first effect of alcohol on sleep quality is that it fragments sleep with brief awakenings. These mostly unnoticed awakenings keep the sleep from being restorative. As a result of being mostly unnoticed awakenings, people fail to link alcohol consumption the night before with feelings of exhaustion the next day. Secondly, alcohol is one of the most powerful suppressors known of a deep sleep state called REM sleep. People consuming even moderate amounts of alcohol in the afternoon or evening will suppress their ability to have REM sleep. Importantly, you don’t have to be using alcohol to levels of abuse to suffer REM sleep disruption consequences. The result is disrupted information integration and degraded recall of anything that was previously learned. Taken to extremes, the pent-up need for REM-sleep can lead to hallucinations, delusions, gross disorientation and death.
Another casualty of sleep deprivation due to overuse of artificial lighting is traffic accidents. While alcohol frequently contributes to car accidents, drowsy driving accidents significantly exceed those caused by alcohol and drugs. For example, with less than 5 hours of sleep, your risk of a car crash increases threefold. With 4 hours or less the night before you are 11.5 times more likely to be involved in a car accident. More dangerous than cars are trucks. Approximately 80% of truck drivers in the US are overweight, with 50% being clinically obese – a perfect recipe for sleep apnea (a chronic type of severe sleep deprivation.) These sleep-deprived drivers are up to five times more likely to be involved in a traffic accident. When these accidents happen, and the driver dies as a result of the accident, they will on average take 4.5 other lives with them. Oddly, governments spend quite a bit educating people about drunk driving and very little about the dangers of driving while sleep-deprived. If wondering why sleep deprivation is a more significant problem than drunk drivers, there is a reason. Far more people are sleep deprived than are driving drunk. Making matters worse, a drunk driver often applies the brakes – just too late. In contrast, a driver that has nodded off, never presses the brake.
You may wonder if you are getting enough sleep? Given the complexity of sleep, as it cycles through various stages, a clinical sleep assessment is needed to thoroughly address this issue. Fortunately, answering two simple questions usually provides a good assessment. First, after waking up in the morning, do you feel like you need more sleep before noon? Second, can you function at your best without caffeine before noon? Both of these urges can be an indication that you are suffering sleep deficiency. Unfortunately, a sleep debt can never be repaid. There is no way of reversing the effects of sleep loss by sleeping longer the next day or on the weekend. Granted, extra sleep on the weekend may feel great. However, you can never regain what was lost. In older adults with the greatest loss of deep sleep, the effect of overnight forgetting is often misdiagnosed as dementia.
Numerous functions of the brain are affected by and restored by sleep. If you were a participant in a sleep study, it could be determined from the quality of your sleep, how much you would remember for an upcoming memory test. That’s how important the link is between sleep and memory consolidation. Clearly, an effect of sleep is help access memories that you could not have retrieve before sleep. A reasonable analogy is a computer hard drive where some files have been corrupted and therefore become inaccessible. Then, during the night a recovery service repairs the corrupted links and come morning, all files can be accessed. If you have awakened in the morning with the ‘ah yes’ feeling then you have experienced the memory enhancing effect quality sleep provides.
Imagine for a moment a news report that scientist have discovered a revolutionary treatment that makes you live longer, enhances your memory, makes you more creative, makes you look more attractive, keeps you slim, and lowers food cravings. As a bonus, this revolutionary treatment protects you from cancer, protects you from dementia, wards off colds and flu, lowers your risk of heart attacks and stroke, and reduces your risk of diabetes. Would you be interested? Well, here is the report. The evidence supporting quality sleep as the elixir has been documented in over 17,000 well scrutinized scientific reports. As for how to gain these benefits, be sure to read the rules that follow for getting the best from your sleep.
Nancy Neighbors, MD
Tips for Healthy Sleep
- Stick to a sleep schedule. It’s best to go to bed and wake up at the same time each day. Know that sleeping later on weekends won’t make up for a lack of sleep during the week. Even worse, it will make it harder to wake up early the next day. To help get the new habit started, set an alarm for bedtime.
- Exercise is great for general health and therefore helps with getting quality sleep. Exercise closer than two hours before your bedtime can be counterproductive to quality sleep.
- Avoid caffeine and nicotine. This includes coffee, sodas, certain teas, and chocolate. Depending on your genetics, even a cup of coffee in the late afternoon can make it harder to fall asleep. Smokers tend to have poor quality sleep (sleep very lightly) and often wake up due to nicotine withdrawal.
- Avoid alcoholic drinks before bed. Having an alcoholic beverage before sleep may help you feel relaxed, but keeps you in the lighter stages of sleep without adequate REM or Non-REM stages of sleep.
- Avoid large meals and beverages late at night. A large meal can cause indigestion, which interferes with sleep. Drinking too many fluids at night can cause frequent awakenings to urinate.
- Avoid medicines that delay or disrupt your sleep. Some over-the-counter and herbal remedies for coughs, colds, or allergies, can disrupt sleep patterns.
- Avoid late afternoon naps that can make it harder to fall asleep at night.
- Relax before bed. Leave time in the evening to unwind. A relaxing activity, such as reading, listening to music, or meditation should be part of your bedtime ritual.
- Take a hot bath before bed. A hot bath helps increase blood flow, that in turn helps reduce your core body temperature. After a bath, you relax and slow down and become more ready to sleep.
- Keep a dark bedroom. Street lights can be blocked with a dark curtain. LED lights from electronics can be turned away from the bed or covered.
- Keep a cool bedroom. You sleep better if the temperature in the room is kept on the cool side. A room at 65 degrees is best.
- Keep a gadget-free bedroom. Get rid of anything in your bedroom that might distract you from sleep, such as noises, lights, or an uncomfortable bed. A TV, cell phone, or computer in the bedroom can be a distraction and deprive you of sleep. Having a comfortable mattress and pillow can help promote a good night’s sleep.
- Have the right sunlight exposure. Daylight is key to regulating daily sleep patterns. Get outside for natural sunlight at least thirty minutes each day. If possible, wake up with the sun or use very bright lights in the morning. If you have problems falling asleep, be sure to get an hour of exposure to morning sunlight and turn down the lights before bedtime.
- Don’t lie in bed awake. If you find yourself still awake after staying in bed for more than twenty minutes, get up and do some relaxing activity until you feel sleepy. The anxiety of wondering when you will sleep can make it harder to fall asleep.
Need More Information?
The book, “Why We Sleep” by Matthew Walker, PhD is available in the local library and is an excellent introduction to the subject of sleep. The book consolidates research about how sleep quality affects our lives. The book also provides research findings about the importance of dreams and why they are important. Additional resources are listed below.
- Brain Basics – Understanding Sleep National Institute of Health
- Are You Sleep-Deprived? By Michael J. Twery, PhD (article is near middle of magazine)
For the adventurous, there are a few do it yourself devices for measuring some aspects of sleep quality. At present, however, an accurate assessment of all stages of sleep is not possible without the help of a doctor trained in sleep medicine. For many, sleep apnea is the major issue, and for that type of assessment, a number of inexpensive nighttime data loggers are available that measure oxygen levels (pulse oximetry). While the information gained from a do it yourself assessment may motivate a person to seek help, a doctor trained in sleep medicine will still be needed to arrive at the best recommendation for addressing the underlying health issue.