Russell Foster is a circadian neuroscientist that studies the sleep cycles of the brain. He says (8.3) that, statistically, the average human spends 36% of their life asleep. Margaret Thatcher once famously said, “sleep is for wimps”. It’s as if sleep is an illness or an enemy.
The brain does not shut down while sleeping. In fact, some parts of the brain are more active while sleeping than when awake. Why do we sleep? Interestingly, there is very little consensus among scientists when answering this question. Here are two possible reasons for sleeping:
a) restoration. There are numerous genes that are associated with restoration and metabolic pathways and these genes are only turned on while sleeping. The neural connections required for problem-solving and creative thinking seem to be strengthened during sleep.
b) brain processing and memory consolidation. Our ability to solve complex problems is significantly enhanced following sleep. Some research indicates that sleep gives you a threefold advantage and enhances creativity.
Foster says that most of us are sleep deprived. In the 1950s most of us were getting approximately 8 hours of sleep a night. Now all we sleep an average of 6 1/2 hours. Teenagers need an average of nine hours of sleep but often only get five. Shift workers make up 20 to 30% of the population (depending on the part of the world you live in) and the body does adapt somewhat to shiftwork but it never fully adapts. The body is hardwired to want to sleep when it is dark and to be awake when it is light. Therefore, the quality of sleep is very poor. Shift workers and people suffering from jet lag end up in situations where the brain involuntarily transitions into microsleep.
There is research indicating that approximately 31% of drivers will microsleep at least once in their lives. In the United States, there is research indicating that 100,000 car accidents per year were related to sleep deprivation.
Foster says that when you are tired you have poor memory, poor judgment, low levels of creativity, and increased impulsiveness. When the brain is tired it craves things to wake it up such as stimulants like caffeine. There is also a strong link between the lack of sleep and weight gain. If you sleep less than five hours per night you have a 50% increased chance of being obese. Lack of sleep causes the brain to crave carbohydrates, specifically sugar. There is also a strong link with stress. In simple terms, tired people are stressed people. Sustained stress is an even bigger problem because it negatively impacts the body’s immune system. Increased levels of stress also cause higher levels of glucose in the body and this can eventually lead to glucose intolerance which, in turn, can lead to diabetes. Stress also increases the risk of cardiovascular disease.
How to get high quality sleep. Foster says that you should:
a) make your bedroom a haven for sleep. It should be as dark as possible and slightly cool. Light increases levels of alertness so you should reduce exposure to bright light for approximately 30 minutes before sleep.
b) minimize the consumption of caffeine after lunch.
c) seek out morning light. The body uses morning light to adjust its circadian clock.
We need eight hours of sleep a night. Foster says that this is just an average. Some people need seven. Some need nine. You need to listen to your body to figure out what you need. Another myth is that old people need less sleep. This is not correct. Although sleep for all the people may become fragmented the sleep requirement does not fall. Another myth is that going to sleep early and waking up early is better than the other way around. Foster says this is wrong and absurd. There is literally no evidence indicating that going to sleep early waking up early has any benefit of any kind.
The link between sleep and mental well-being.
Foster says that, in almost all cases of mental illness, there is evidence of sleep disruption and or sleep deprivation. Other research indicates that sleep deprivation precedes certain mental illnesses. Young people that have been diagnosed with bipolar have been shown to have sleep disorders prior to being diagnosed as bipolar. There is also research indicating that sleep disruption aggravates existing mental illness.
Foster that the summary is that we have to take sleep seriously. Adequate sleep improves your concentration, attention, decision-making, creativity, social skills, and overall health. It also reduces your stress, improves your mood, reduces your tendency to drink or consume drugs.