Sleep is for wimps. Or is it?

The world of high profile leaders, politicians and CEOs is filled with people claiming to survive on fumes when it comes to sleep. If anything the impression that comes out is that of sleep as a wastage of time. This is also a majority viewpoint in many parts of Asia where it is not uncommon for students to trade sleep for extra study hours and perfectly normal for adults to prioritize work, commuting or social life for sleep. Unsurprisingly, Japan, Korea, Singapore, and Hong Kong rank the worst when it comes to sleep.

Is there a shred of truth to this or this advice is taking us towards an impending doom? Do we have a clear answer or this is still a controversial topic where even the experts do not agree?

Yes, we still do not fully understand sleep!

In the last century, we have made some incredible advances in science and technology. We could find planets in other solar systems, send rovers to Mars and understand the origins of our universe by smashing particles in massive colliders. We live in a time when being able to communicate with anyone in the blink of an eye is taken for granted. Yet we know very little about one of the most fundamental aspects of our own life — Sleep. We spend one-third of our lives in sleep. Every animal with half a brain (pun intended) sleeps, yet we do not fully understand why! But that does not mean we do not know the importance of sleep, how strongly it is connected to health. Sleep is a multi-faceted process and way more nuanced than most people realize. Let’s see what we already know about it:

Sleep loss reduces your lifespan and quality of life. There is a complex bi-directional relationship between sleep and health. But one thing that emerged out of the hundreds of studies conducted till now is that sleep loss increases all-cause mortality! In a systematic review published in 2010, the authors who followed 1.38 million people over a period of 4 to 25 years and 100,000+ deaths showed an unambiguous and consistent pattern of increased risk of death for both short (<7 hrs) and long (> 8 hrs) sleepers. The reason why many people fail to see this pattern is because sleep loss rarely ever kills anyone directly. It increases the risk of a plethora of diseases like diabetes, Alzheimer’s, obesity and cardiovascular problems and these diseases are what kills someone. So, the weight gain that is happening despite eating well and exercising might be due to the lack of good quality sleep!

Sleep debt is a real thing. One of the most striking figures that I came across during my post-doc was that of cumulative accumulation of sleep debt. PVT which stands for Psychomotor Vigilance Test, is a 10-minutes simple reaction time task that measures your vigilance. A lapse is a reaction time of greater than 500 milliseconds, which could be fatal when operating heavy machinery or driving a vehicle. The red graph is from subjects who slept 5 hrs a night and the one in blue is from subjects who slept 9 hrs a night. The accumulation of sleep debt over the days (M1 to M7) is scary. Which brings me to my next point.

Drowsy driving is potentially a much bigger issue than drunk driving. I’m sure a clear majority of us sleep more during the weekends compared to work days. This is a strong indication that we are sleeping less than we should. If the previous graph shows us one thing, it is that this cumulative sleep debt could lead to fatal accidents. As per the AAA, nearly 400,000 accidents are attributed to drowsy driving every year in the US of which nearly 100,000 resulted in injuries and over 6000 were fatal. While drowsy driving is a bigger issue compared to drunk driving, the inability to effectively measure drowsiness means it is much more challenging to legally enforce.

We are a poor judge of our own sleepiness. Just like your friend who gets blind drunk but insists that he is perfectly fine, we are poor judges of our sleepiness levels. Time and again, research shows a complete dissociation between objective and subjective measures of sleepiness. This highlights the need for spreading awareness about sleep deprivation in general and drowsy driving in particular.

Light and timing play a vital role in sleep. Sleep is a combination of two different processes, one is the circadian process and a homeostatic process. The circadian process is near 24-hour in-build clock built into our bodies. The homeostatic process is the accumulating sleep pressure when you are awake, and which dissipates only when you sleep. Your sleep pressure at any given time is a combination of these two processes. There are times of the day where both the processes add up while at other time one counteracts the other. Any disruption to this rhythm can cause all sorts of problem. This disruption now happens routinely when you travel across time zones and check that social media post on your phone on your bed. Light is a powerful cue for our internal clock, and artificial lights and increased exposure to bright screens is making things worst. I could not recommend this talk by Prof Panda enough:

The economic impact of sleep loss is massive. Perhaps the easiest way to convince governments and corporations is to show the economic impact of sleep loss which as per Rand Corporation is as much as 1% to 3% of the GDP. We are talking about hundreds of billions of dollars for developed countries.

So, what about Margaret Thatcher? If there is so much evidence supporting sleep, how do you explain Margaret Thatcher and the few dozen high profile and influential people who are doing just fine without much sleep? I have three explanations:

3. They are outright lying. We always look up to our heroes and hold them up on a pedestal. We think of them as super-human and any form of weakness is not easily tolerated. It goes in their favor when they say they accomplished their successes while barely sleeping enough especially when the society still holds the notion that sleep is an indulgence and a waste of time. I certainly do not have any data to back this up, but when President Trump says he only sleeps 3 to 4 hrs because he wants to be ahead of his competitor, I just chuckle and say really?

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