The importance of sleep has even inspired William Shakespeare with his famous, “Sleep that knits up the raveled sleeve of care” (in Macbeth). In our day and age, sleep still retains its importance for health, both physical and mental. Inadequate sleep causes the body to increase levels of cortisol, which predisposes to weight gain and diabetes. This is aggravated by the fact that sleep deprivation decreases leptin (the hormone of “fullness”) and increases levels of ghrelin (hormone of hunger). There appears to be a clear association between lack of sleep and weight gain in middle aged and younger subjects. Sleep deprivation also negatively effects wound healing and the immune response, making us more subject to all sorts of infectious diseases.
The greatest negative effects, however, are clearly related to the brain. Lack of sleep causes loss of concentration, impaired memory retention and inattention. It is estimated that twenty percent of bad car accidents are caused by driver fatigue. This amounts to over 250,000 accidents a year involving over 80,000 drivers who have fallen asleep at the wheel. Eighteen hours without sleep is equivalent to a blood alcohol level of 0.05% (the legal limit in Western Europe).
Sleep deprivations affects such critical jobs, among them truck drivers, pilots and doctors. Medical residents now must limit their hours without sleep because of a dangerous increase in errors associated with sleep deprivation. For all students, their performance in fine motor skills drops with less sleep and their emotional responses become more erratic and disinhibited. Most college students report receiving less than 6 hours of nightly sleep. And 25% of high school students report falling asleep during class at least once. Worse yet, significant sleep loss increases anxiety, irritability, headaches, depression, suicidal ideation and psychosis, even resulting in hallucinations.
With less than five hours of nightly sleep, the risk of death jumps by 15% (in a Harvard study). This may be related to an increase in blood pressure and the subsequent increases in heart disease and stroke. With over a third of the adult U.S. population reporting insomnia and associated inadequate sleep, the extent and severity of the problem becomes apparent. Sleep, like adequate exercise and a healthy diet, should be considered indispensable for young people and adults alike. Although we can sometimes get by with less sleep, consistent sleeplessness can have disastrous short- and long-term consequences.
While talking about sleep, I would be remiss to not talk about “Safe Sleep”. Safe sleep refers to infants and is geared to reducing the 3,490 infants that die each year from Sudden Infant Death (SIDS), Accident Suffocation and Strangulation in Bed (ASSB) and some “Unknown Causes”. Although the number of Sudden Unexpected Infant Deaths (SUID) has decreased over the last two decades (from around 150/100,000 live births to around 80/100,000), it still remains an incredible tragedy.
Some simple steps can reduce the rate of SIDS even further: (1) put infants on their backs (Back To Sleep); (2) Never co-sleep with adults; (3) Use a crib with a firm mattress and no bumpers, blankets, toys or pillows; (4) Use light, one-piece sleepers; (5) Breastfeed; and (6) Never smoke around an infant. These simple steps can reduce even more the number of sudden infant deaths.
So if you are an adult, adolescent or infant, sleep remains a critical component of a healthy life and “Safe Sleep” for infants can actually save their lives as well.