In the TED speech Why do we sleep? by circadian neuroscientist, Russell Foster shares three popular theories about why we sleep and busts a few myths about how much sleep we need at different ages.
SLEEP Must know facts
The average person spends 36 percent of his/her lifetime asleep.
If you live to 90, about 30 years of that will be spent entirely asleep.
Our attitude towards sleep in the 20th century: We used Thomas Edison’s light bulb to invade the night and we occupied the dark, and in the process, we have treated sleep more like an illness than a necessity.
While we tend to think that we don’t do much when we are asleep, there is actually a lot happening in our brain – some areas are even more active during sleep than during our wake state.
Within the brain, the set of genes associated with restoration and rebuilding metabolic pathways have been shown to be turned on only during sleep.
Most important activity that sleep confers is memory consolidation. Not simply laying down memory and recalling it, but the ability to come up with anything from novel ideas to solutions to complex problems is hugely enhanced by a night’s sleep. Important neural connections are improved while less important ones fade away.
Sleep deprivation and weight gain: If you sleep around five hours or less every night, you have a 50 percent increased likelihood of being obese. The reason? Sleep loss gives rise to release of the hormone ghrelin, the hunger hormone. Ghrelin makes the brain crave carbohydrates and particularly sugars. There is and undeniable correlation between sleep deprivation and a predisposition for weight gain.
If you sleep around five hours or less every night, you have a 50 percent increased likelihood of being obese.
How much sleep is right for me?
It depends on two factors: The quality of sleep and the amount of sleep.
If you wake up with a headache, need lots of stimulants to keep awake, are grumpy and irritable, it means that either you had less sleep than your body requires, your quality of sleep is poor or both.
A huge sector of our society is sleep deprived. Lets look at our sleep-o-meter:
In the 1950s, reliable data suggests that most of us were getting around eight hours of sleep a night. Nowadays, we sleep one and a half to two hours less every night.
Teenagers need about nine hours of sleep for full brain performance. Many of them, on a school night, are only getting five hours of sleep. It’s simply not enough.
About 20 percent of the working population works a night shift. Our body clock does not shift to the demands of working at night. It’s locked onto the same light-dark cycle as the rest of us. So, when a shift worker goes home to try to sleep during the day, desperately tired, the body clock is saying “wake up. It’s time to be awake.” So the quality of sleep you get during the day is relatively poor. This impairs memory consolidation, recall, creative thinking, problem solving aptitude, and appetite. This lack of restorative sleep also increases impulsiveness and overall poor judgment.
Some myths about Sleep:
Teenagers are lazy: No, they are not. They have a biological predisposition to go to bed early and wake up late. This is because their brains need that much restoration for memory consolidation, building up creative skills for their young brains to face challenges ahead. So, give them a break!
Old people need less sleep: Not true. The sleep demands do not decrease with age. What’s different though is that sleep duration becomes less robust. Elderly individuals wake up after about five hours of sleep. While they sleep in fragments, the overall sleep requirements remain the same.
So, take sleep seriously. Don’t ignore what your body is telling you. A good night’s sleep improves your concentration, attention, decision-making, creativity, social skills and thus, improves your overall health and well being.
Sleep well and be healthy !
Teenagers are lazy: No, they are not. They have a biological predisposition to go to bed early and wake up late.
Russell Foster studies sleep and its role in our lives.