Dr. Rob Carter III, PhD, MPH
CoAuthor of Morning Mind
We spend 30 percent of our lives asleep or at least trying to get to sleep. But do you know why? It’s amazing how little we know about this nightly habit! Research is revealing that sleep is a critical aspect of human health and performance. Lack of sleep increases the risk of disease, while quality sleep boosts well-being and cognitive skills. Starting the new year with a resolution to sleep better is the best thing you can do for your long-term health.
When You Skip a Night's Sleep
Skip a night’s sleep and you will likely experience impaired perception, reduced concentration and slower reactions. Continue to skimp on slumber and the cognitive deficits increase as memory, emotional processing and interpersonal skills are all impacted. Behavioral and emotional deficits, including amplified aggression, build until we restore the balance by getting some sleep. It takes two nights to recover from the acute sleep deprivation caused by a single sleepless night. Unfortunately, recovery from continued and chronic sleep deprivation is not so simple. Like drinking alcohol, the impact of insufficient sleep is cumulative, and its cognitive deficits increase the risk of accidents and induce weight gain and disease. Chronic lack of sleep impairs glucose function, increases blood pressure and induces inflammation. Sleep is not a luxury or a lazy habit; it is a vital component of human health. Population-based studies show strong correlations between sleep issues and the risk of heart disease, diabetes and stroke. Lack of sleep is a significant public health issue, with over 70 million Americans suffering from chronic wakefulness and its impact on their well-being. Reduced immune function and growth suppression are two more alarming consequences of a chronic lack of sleep. The pandemic of sleep deprivation in a society of night-owls, workaholics, media-addicts and shift-workers is also correlated with the epidemic of obesity. Brain-derived neurotrophic factor (a neurotransmitter modulator) and metabolic regulating hormones are impacted by sleep deprivation. Lack of sleep influences food choices and appetite: increasing carbohydrate consumption and resulting in weight gain.
"Reduced immune function and growth suppression are two more alarming consequences of a chronic lack of sleep."
Lack of Sleep & Disease
Sleep apnea is when air flow is restricted during sleep and for brief periods breathing stops when airways are blocked by soft tissue. The condition is associated with loud snoring and is made worse by the weight of excess neck tissue. The sleep disturbance catalyzes weight gain (combined with obesity and diabetes), exacerbating the problem further. Sleep apnea is one of the reasons we are suffering with our slumber and is directly linked to both neurological and metabolic disturbances. The complex relationships between sleep, weight gain and disease are highlighting the issues of our sedentary and sleep-restricted lifestyles. Along with exercise, sleep is a vital lifestyle prescription (LSx), superior to pharmaceutical drugs, with no side effects and cumulative health benefits. When we sleep, the brain’s metabolic waste products are removed, and they pass through the normally impermeable blood-brain barrier. Sleep deprivation causes a build-up of waste, impacting cognitive abilities and mental performance. Sleep is a neuroprotective activity that replenishes and recharges the brain while removing the toxic byproducts of normal metabolism. The lymphatic system is responsible for clearing waste and replenishing nutrients in the central nervous system and brain, but it is only active when we sleep. Sleep deprivation reduces the time dedicated to this critical detox function and is associated with neurodegenerative disorders like Alzheimer’s. Sleep restriction studies, which mimic our modern wakeful lives, demonstrate that toxins build up when the glymphatic system is unable to fully rejuvenate the brain overnight.
"Sleep is not a luxury or a lazy habit; it is a vital component of human health."
There are profound benefits associated with the right amount of quality sleep; seven hours is perfect for most people. Cognitive performance, decision making, improved memory, better moral judgment and enhanced focus are just some of the many benefits of being well rested. A study of Swiss Army recruits found that just 40 minutes of extra sleep reduced injuries during physical training by 12 percent due to increased attention and focus. Routine is the key to improving your sleep and delivering enhanced cognition and reduced disease risk. A consistent sleep schedule, aligned to natural daylight hours and circadian rhythms, improves the duration and effectiveness of your nightly brain refresh. Training yourself to go to bed earlier, without screens or disruptive blue light, is key to resetting rhythms and supporting natural sleep. A soothing pre-sleep routine that avoids stimulation and relaxes the body will prepare your body to drift away. The calming scent of lavender is a mild sedative, while chamomile or valerian herbal teas help you get to sleep quicker. Wind down with gentle activities like reading, doing yoga with dim lighting and peaceful music, or listening to a guided meditation to help your brain and body relax. Exercise is a great way to tire yourself out, and it has a positive synergistic relationship with sleep, but avoid intense exercise close to bedtime. Keep your bed and bedroom free from devices, cool and uncluttered and reserved just for sleep, not late-night multimedia pizza parties.
Tactics + Recommendations
You can increase cognitive reserves by banking a few hours of sleep in advance when you know you are going to be deprived. Soldiers getting a couple of extra hours’ kip before missions showed significant improvements in their performance under stressful conditions. Napping is another tool in your sleep arsenal, and strategic daytime naps restore wakefulness while promoting performance. A 30-minute nap is enough to revitalize you without the loss of productivity or sleep inertia associated with longer snoozes. Resolve to relax, negotiate a nap, and strive to sleep more in 2019. The physical, mental and emotional benefits of taking the time to rejuvenate are only just starting to be discovered. Get ahead of the game and rest your way to a healthier new year.
Dr. Rob Carter III, PhD, MPH, is a US Army officer, an adjunct professor of emergency medicine at the University of Texas Health Science Center, and an expert on human physiology and performance. Dr. Carter has a doctorate in biomedical sciences and medical physiology, and a Master of Public Health in chronic disease epidemiology.