Human beings spend on average one third of our lives asleep. We know we need to sleep, but most of us have never really given a whole lot of thought to why.
How come we spend seven or eight hours a night immobile and unconscious? What really happens inside our brains and bodies while we are sleeping?
Turns out one of the least studied and most important topics in regards to health and longevity is sleep.
Let’s look at findings for peopled aged 18 to 64.
For that broad demographic, doctors recommend 7-9 hours of sleep, although a lesser amount of 6 hours or greater amount of 10 hours may be appropriate for some. The average American sleeps 6.9 hours a night, but in truth, it is difficult to determine what constitutes a normal quantity of sleep for any given individual.
One approach to figuring out “normal” involves determining how long a patient would sleep if left to awaken spontaneously. An alternative is determining how alert the patient feels after different durations of sleep. Alertness is considered “normal” if the patient wakes feeling refreshed and is capable of moving through the day feeling on top of their game without effort, even when placed in boring or monotonous situations. What we do know is that it is possible for an individual to sleep 8 or more hours and still be sleep deprived. In such cases, the sleep deprivation is usually due to disturbances in the quality of sleep.
Sleep quality is determined by the number of arousals (or awakenings) from sleep during the night, as well as the percentage, duration, and type of sleep stages. As few as 5 arousals per hour of sleep can result in daytime sleepiness and/or performance deficits even after just one night of disruption. Patients are unaware of the arousals, in part because their so-called “duration” can be just seconds long before the individual returns to the same sleep stage he or she was in before the break. Arousals are usually due to sleep disorders (e.g., sleep apnea, periodic leg movements), but they may also occur spontaneously.
The true purpose of sleeping is poorly understood, but multiple theories exist.
Evolutionarily speaking, it would seem that a state in which an animal is unaware of its environment would be dangerous and unlikely to continue as a genetic trait passed on through the centuries. That sleep is observed in all animal species suggests there must be some positive benefits.
What are some of the consequences of sleep deprivation? There are so many, we can only scratch the surface.
Blood pressure can increase and reaction time may slow down.
Appetite may increase with a subsequent increased intake of food and associated risk of obesity.
Cognitive impairment is the most prominent effect of total sleep deprivation or sleep restriction over several nights.
Sleep-deprived individuals tend to take longer to respond to stimuli, particularly when tasks are monotonous and associated with low cognitive demands. Tasks requiring sustained attention can be impaired by even a few hours of sleep loss.
Sleep deprivation may result in a mental state that resembles depression or anxiety, with patients reporting poor mood, irritability, low energy, decreased libido, poor judgment, and other signs of psychologic dysfunction.
In a cross-sectional analysis of a large European study of insulin resistance in otherwise healthy adults. getting too much or too little sleep was associated with an increased diabetes risk among men, but not in women. Reported difficulty falling or staying asleep or sleeping too much was associated with heightened cardiovascular and metabolic risk.
There are numerous solutions for getting a better night sleep; some may be worth trying.
First, make sure you do not have a treatable problem such as sleep apnea.
Try and unwind before bed and definitely do not check email, watch TV, or work out just before going to sleep.
Try turning off all electronic screens at least 30-60 minutes before bed.
Exercise can help you sleep, but try to finish your workout earlier in the day.
Try reading a good book but again, avoid electronics.
Establish a regular bedtime routine.
Caffeine in all forms – coffee, tea, soft drinks, energy drinks, and unfortunately chocolates – late in the day is problematic for many. If you are one of those people, cut back or cut out.
To learn more, listen to Dr. Alan Safdi’s podcast.