By John A. Caldwell, PhD, MA, BSc
For optimal health and well-being, the average adult needs between 7-9 hours of sleep every night. Failure to get the right amount of sleep seriously jeopardizes safety, performance, productivity, and worst of all, your health! The U.S. Centers of Disease Control and Prevention declared insufficient sleep to be a “public health problem” but it’s not only a problem in the U.S., but in other industrialized countries around the world. Significant numbers of people in the United Kingdom, Japan, Germany, Canada, and Australia are sleeping less than the recommended amount, and the demands of our 24/7 society appear to be making matters worse rather than better. From a productivity standpoint, insufficient sleep is costing the world more than $680 billion in lost economic output every single year, and studies estimate that by 2025 the cost will be nearly $800 billion. From a health perspective, the cost of sleep disorders–which often lead to insufficient sleep–is approximately $94.9 billion a year in the United States alone.
How many of us aren’t sleeping enough?
More than a third of both Americans and Australians aren’t getting enough sleep on a regular basis. In fact, 42% of Australians polled in one study were considered to have less than the optimal amount of sleep on a routine basis. This is pretty disturbing since at any given time, someone who sleeps less than 6 hours per night is 13 percent more likely to die from accidents, stroke, cancer, or cardiovascular disease than someone who sleeps between 7 and 9 hours per night. In addition, there are a host of other health-related problems associated with insufficient sleep. In fact, throughout the world, insufficient sleep is considered to be a “public health epidemic.”
How does short sleep cause health and mortality problems?
The reasons underlying the negative impact of short sleep aren’t fully understood at this point, but we do know that habitually short sleep poses a number of adverse effects on the body’s internal functioning. Healthy people who are partially sleep deprived have been shown to experience impaired glucose tolerance, higher cortisol (stress hormone) levels, abnormal nervous system regulation, altered ghrelin and leptin levels (the hormones that govern hunger and satiety), increased inflammatory markers, immune system disfunctions, disruptions in liver and heart antioxidant levels, and increased cellular stress within the brain. Altogether, these and other abnormalities contribute to the development and exacerbation of diseases and ultimately, a shorter lifespan.
What are some of the health consequences of insufficient sleep?
According to a study on the serious health implications of getting less than the recommended amount of sleep, the derailment of the body’s internal systems leads to a startling number of negative health consequences ranging from workplace injuries to well-recognized medical and psychological disorders.
- Cognitive dysfunction. Insufficient sleep increases risk-taking behavior and impulsivity while reducing the capacity for logical reasoning. It also strongly elevates the frequency of mental lapses, leading to loses in attentional capacity and vigilance.
- Mood problems. Chronic insufficient sleep diminishes frustration tolerance; increases moodiness, irritability, nervousness, tension, anxiety, and depression. It even increases post-traumatic stress disorders, alcoholism, and the risk of committing suicide.
- Cardiovascular disease. Shortened sleep has been associated with coronary artery disease, congestive heart failure, and stroke in a number of racial and ethnic groups, and sleep disorders such as obstructive sleep apnea have been shown to increase cardiovascular stress and blood pressure.
- Respiratory disease. An investigation of individuals from European countries demonstrated that shorter sleepers are more likely to experience respiratory symptoms than normal sleepers. These include respiratory tract infections, asthma, and chronic obstructive pulmonary disease among others.
- Immune system degradation. Insufficient sleep has been shown to adversely affect several aspects of immune system functioning, increasing the risk of infectious diseases and reducing the rate of disease recovery.
- Body weight issues. The link between sleep restriction and obesity has been well established. As noted earlier, insufficient sleep causes dysregulation of appetite control hormones—one of the factors contributing to weight gain. Other factors are changes in the rate of energy expenditure, poor impulse control, and loss of motivation to engage in physical activity.
- Diabetes. Insufficient sleep increases insulin resistance which leads to elevated blood glucose levels and ultimately to prediabetes and Type 2 diabetes. In addition, insulin resistance is associated with several other conditions, including obesity and cardiovascular disease.
- Digestive diseases. Sleep disturbances have been linked to a number of digestive diseases including irritable bowel syndrome, dyspepsia, duodenal ulcers, and gastro-esophageal reflux disease. Unfortunately, the presence of these problems often propagates a vicious cycle in which the symptoms cause sleep disruptions that shorten sleep even more.
- Headaches. Research shows that people who don’t sleep enough are more susceptible to migraine headaches than their well-rested counterparts. Those who are overweight and elderly are particularly at risk.
- Cancer. Short sleepers appear more likely to develop cancerous tumors. Women who don’t get the recommended amounts of sleep should be concerned with their increased risk of breast cancer. Short sleep duration has specifically been associated with a greater risk of colon polyps that can become cancer. Some research has tied short sleep to a higher likelihood of stomach cancer and found potential correlations with cancers of the thyroid, bladder, head, and neck.
In addition to the forgoing, short sleep has been associated with neurological disorders such as Parkinson’s and Alzheimer’s disease, sexual dysfunctions, and relationship difficulties both at home and at work. Adding these and other health problems to the already extensive list of short-sleep-related industrial, transportation, and other workplace safety issues, makes it clear that insufficient sleep is a massive, although often unrecognized, public health concern.
What can be done?
Raising public awareness of the true importance of sleep and providing education on good sleep hygiene to all members of society should become a priority for medical practitioners, businesses, and policymakers. Then, we should all take responsibility for making sure we as individuals get the right amount of sleep on a routine basis. Chattu et al. (2018) suggest people set predictable sleep and wake-up times, avoid using electronic devices prior to bedtime, and take advantage of the sleep-promoting effects of regular physical exercise. Employers should be made aware of the significance of sleep in the overall health and productivity equation, and strive to provide work schedules that ensure adequate time for off-duty sleep. School officials should establish later school start times that avoid interfering with students’ sleep needs–sleep is especially important during adolescence. Meanwhile, policymakers should encourage education to raise everyone’s awareness about the importance of sleep. Sleep is critical for health and wellbeing, and we all need to treat it with the respect it deserves!
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