9 things you didn't know about sleep

Eight hours of sleep every night was once considered the norm.

However, society has become so fast-paced that many working adults are surviving on less sleep than before. Many feel that there is too much to do within a day, and hence make do with as little as four to five hours of sleep a day. Such voluntary sleep deprivation can have significant adverse effects on one's day-to-day performance and result in numerous health problems in the long run.
So before you dismiss those eight hours in bed as a waste of precious time, read on to learn why sleep is so crucial to one's health and wellbeing.

The link between sleep and memory
Have you been having problems remembering things lately?
Before you panic and start to wonder if you are showing signs of dementia, ask yourself if you have been sleeping well.
Dr Ng Beng Yeong and Dr Victor Kwok from Singapore General Hospital note that people who sleep poorly tend to be more forgetful. This is because sleep is a time when memories get consolidated Hence, when you don't sleep well, your brain is unable to properly process and store your memories.

Stave off Alzheimer's - in bed
If you are worried about developing Alzheimer's disease, one thing you can do to reduce your risks of developing this form of dementia is to get sufficient sleep.
Alzheimer's disease is characterized by a plaque-like substance - composed primarily of a protein fragment called amyloid beta - that builds up in the brain.
Sleep results in the clearance of amyloid beta, says Professor Michael Chee from the Cognitive Neuroscience Laboratory and Neuroscience and Behavioral Disorders Program at Duke-NUS Graduate Medical School . Hence, if you want to minimise amyloid beta buildup, you should make sure that you get enough sleep.

"I'm making the right decision...am I?"
Chronic sleep loss can actually distort your perception of your own abilities.
Prof Chee says that people who chronically lose sleep are not able to tell how badly their cognitive brain functions are affected.
Moreover, sleep deprivation can dangerously affect decision making in risky situations such as driving, he adds.
Sleep-deprived people are also more likely to make poor decisions because they struggle to remember and interpret important information. Their decisions are based on faulty or incomplete information collected and logged by a sleepy brain, say researchers from Washington State University .


Sleep more, lose weight
Lack of sleep actually affects the body's metabolism, notes Prof Chee. This increases one's chances of gaining weight or even becoming obese.
Sleep loss also affects one's overall health. "People who sleep less than they need are less likely to take part in activities that improve health. They tend not to exercise, eat unhealthy foods and engage in less leisure activities," he adds.


Power naps
A short siesta in the afternoon can be good for you, research has shown.
However, Dr Lim Li Ling, a consultant neurologist in private practice, advises against taking long daytime naps unless one is sleep deprived.
"Afternoon naps, if taken, should not exceed 20 to 30 minutes," says Dr Lim, who is also the Director of the Sleep Disorders Unit at Singapore General Hospital .. Long naps can make it harder to fall asleep at bedtime.


Should I work out or not?
Exercise is good for one's overall health. However, Dr Lim cautions against vigorous physical activity too close to bedtime.
Aerobic exercises such as running, swimming or cycling may make you tired, but the adrenaline produced during vigorous workouts can actually interfere with sleep.
Dr Lim says that one should not engage in vigorous exercise four hours before sleep.


Caffeine fiend
If you drink coffee regularly, try not to do so after lunchtime.
Dr Ng and Dr Kwok say that it takes approximately five hours for your body to remove just half the amount of caffeine in the coffee you imbibe.

More dangerous than a drunkard
Be careful if you cannot get enough sleep, especially if you are driving or operating machinery.
Dr Ng and Dr Kwok say that prolonged sleep deprivation can significantly impair one's alertness and brain function.
A person with sleep deprivation may perform even worse than someone who is drunk, they add.

Bananas a cure for insomnia?
Countless magazines and lifestyle resources recommend taking a glass of milk or eating a banana in order to make you sleepy. Such foods contain tryptophan, an amino-acid which has been linked to sleep.
However, such "tryptophan snacks" have not been shown to induce sleep, say Dr Ng and Dr Kwok.
In fact, some health resources note that over twenty glasses of milk would be needed in order to provide sufficient levels of tryptophan to make one sleepy.