Hear what he has to say about sleep. For those of you who believe that you can regularly get by on 5-6 hours of sleep, he doesn't have good news for you.
The rest of the interview with Professor Chee is found in the article below. I hope you enjoy it.
Michael Chee (MC): Sleep is important to everyone – it doesn’t matter if you are child, a young, old or middle aged, or busy. I would put it at the same level of importance to life as good nutrition. We pay so much attention to having good meals – paying attention to macro-nutrients and micro-nutrients – and there are a lot of fad diets around, but we don’t pay enough attention to sleep, which is absolutely critical for adequate day time functioning and overall health.
MC: I will preface these comments by saying that sleep deprivation is used as a form of torture by militaries around the world. It has devastating effects --- it serves to disorient, to weaken, to break the will, to force bodily as well as mental discomfort, without leaving obvious marks. When we are sleep deprived, there are several negative outcomes. The negative effects of shortened sleep include early mortality (i.e., you will die earlier) than if you had a good optimal level of sleep. There is an increased risk of illnesses, that include diabetes, cardiovascular disease, stroke, and Alzheimer’s Disease. There is also an increase risk of accidents and of depression. Finally, from the employers’ perspective, sleep loss is also increased absenteeism, and even “presenteeism” – where you are present at the office, but not really functioning. Unfortunately, these consequences of inadequate sleep are often attributed to other factors.
MC: Even if it is just one or two nights, there are deficits in attention, processing speed, and vigilance.
Degradation in blood sugar control --- this has been shown to occur after just one night of sleep deprivation. Similarly, dysregulation of blood pressure and cardiac rhythm, can also result.
After only one or two nights or rarely, these negative effects can be washed out with subsequent nights of sleep. However, if they are encountered regularly, you are likely to encounter long-term impact on health.
MC: You pose an interesting but hypothetical situation. Most people, who are massively sleep restricted, to the point where they can feel it the next day, are usually in jobs or lifestyles that require their consent to these conditions. Most of these jobs involve sleep curtailment that begins with 1-2 nights, then it gradually becomes 6 nights. I would liken this to the analogy of boiling a frog. If you put the frog into hot water, it will immediately jump out. But if you raise the temperature gradually, it may eventually get cooked without responding. I think this is the state that most people are in these days in the developed world – they don’t realize the harm they are doing themselves in their relentless pursuit of a ‘better life’.
MC: I would like to see the empirical evidence on people who are so called able to “train themselves” to get by with less sleep. While there is quite a variation with individual sleep need, there is no clear evidence in humans that the sleep need can be reduced by repeated exposure to sleep loss.
It is tantamount to saying, repeated deprivation of Vitamin C can somehow result in resistance to it’s deficiency. This is wishful thinking.
MC: There is good empirical evidence that regular exercise improves the quality of sleep. The arbitrage between exercise and sleep --- it’s like trying to say, I don’t have enough Vitamin C but I will try to make it up with Vitamin D.
MC: Taking a nap in the afternoon has benefits. Vigilance (i.e., paying attention) improves immediately after the nap and in the early evening but this benefit wears off the following day. It is not a replacement for getting enough nocturnal sleep.
MC: If you need a nap, do this in the afternoon, rather than the early evening, and don’t nap for more than an hour. The reason for napping in the mid afternoon, is because it occurs at a favorable circadian phase, a time when the brain are more predisposed to sleeping. If you nap at between 7pm to 9pm in the ‘forbidden zone’ it might interfere with nocturnal sleep. This of course doesn’t apply to someone who is jet-lagged and has a body clock that is out of synch.
MC: This is generally fine but if you have to work on the night shift, it is preferable do it for a stretch of time – weeks or months rather than days. Flipping back and forth between day and night shifts doesn’t allow the body to adjust. This produces sleep/wake cycles that are similar to jetlag. People normally who engage in this “social jetlag” tend to have wider waistlines, are more prone to drinking alcohol and are at higher risk for diabetes. Further, most night shift workers still want to maintain social contact and it is likely that most of their friends are free to see them only during daytime, a time when they should be sleeping.
MC: Metabolic waste from neuronal activity accumulates in the brain during waking hours. . When you sleep, and enter slow-wave sleep (deep sleep), channels in the brain open-up and conduct away these metabolic waste products. If you don’t get enough sleep, these waste products can accumulate and contribute to the development of neurodegenerative diseases like Alzheimer’s Disease.
Inadequate sleep can also contribute to the decline in cognition through the effects of increased stress. Stress has adverse consequences for the hippocampus (the part of the brain, responsible for short term memory). Finally, there are also risks to brain health from the associated increase in risk for cardiovascular and cerebrovascular disease.
MC: Deep sleep is very strong defended in children and young adults. So, if you are sleep deprived, you tend to recover deep sleep first! This typically will occur in the first part of the night. We found in our studies that even adolescents sleep restricted to 5 hours of sleep a night, are able to recover their deep sleep in a few hours of sleep. But as you get older, slow wave sleep (deep sleep) tends to be reduced and so this could be why eventually we experience negative effects on brain health.
Last year, Prof Chee was instrumental in encouraging a prominent school in Singapore to start 45 minutes later each day, so that the students could get extra sleep. On the right is the video put together by Channel News Asia on this topic.