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[3-Minute Blog] How Sleep Impacts Your Immune System

Reading time: 3 minutes and 26 seconds

In Why We Sleep, I briefly discussed the benefits of sleeping for our overall health, and particularly our brain health. 

In this article, I’ll continue to explore the health benefits of sleep. 

Let me start with one of my most favourite quotes by Dr Matthew Walker from his book. He says, “There is no aspect of a human being’s wellness that isn’t eroded by a lack of sleep. EVERY single disease that’s killing us in the developed world has causal links to it.

Sleep thus becomes not just one of the pillars of our health, but the very foundation of our health. 

Based on rigorously researched studies, here are some of the damages that happen to our body when we sleep less than the bare minimum of 7-hours a day. 

How Your Lack of Sleep Wrecks Your Immune System

One of the areas that are most affected by a lack of sleep is your immune system. A study from the University of California shows that reducing your sleep to just four hours for one single night drops your natural killer cell activity to a level of 72%. 

Your natural killer cells are a critical part of your immune defence arsenal. These killer cells are responsible for identifying and destroying malignant cancer cells. As you probably know, we all have cancer cells within our body, and what really prevents the formation of full-on cancer, are these natural killer cells. Now imagine what happens to your immune system after months of insufficient sleep! 

OK, sleeping for four hours sounds extreme for you and you may be among those who get a regular six hours of sleep. Fine, if that is you, please read this study.  

Researchers deprived a group of individuals to only 6 hours of sleep per night for just one week. Here is what they found. 711 genes of the ~20,000 genes in the human genome (~3%) were distorted in a single week of sleep deprivation. 

Some of the genes that are associated with the immune system were down-regulated, in other words, the immune system became weaker. And some other genes that are associated with tumour promotion, chronic inflammation, and stress were up-regulated, meaning that this accelerated the already bad condition. All of these happened just due to one single week of sleep deprivation. 

Conclusion: You are genetically modifying yourself by not getting enough sleep.

Cardiovascular Disease is Accelerated by Sleep Deprivation

More than 1.5 billion people in 70 countries around the world observe daylight savings time every year. It’s an excellent opportunity for scientists to observe what this one-hour sleep loss does to our human body. They found some fascinating correlations: 

  • In the spring, when we lose an hour of sleep – there’s a 24% rise increase in heart attacks the following day
  • In the fall when we gain an hour of sleep – there’s a 21% reduction in heart attacks the following day

Another study found that getting an average of five hours of sleep or less over five years leads to a 200-300% increased risk of calcification of the coronary artery. People who are under-slept have overactive sympathetic nervous systems (the flight or fight nervous system), which results in more circulating adrenaline, higher spikes of cortisol, and blunted levels of growth hormone (all of which are tied to cardiovascular diseases).

Even a loss of only three hours of sleep will result in increased blood pressure and heart rate. 

But these are not the only dangers of lack of sleep, here are a few more. 

 A lack of sleep:

  • Increases your risk of Alzheimer’s Disease
  • Reduces the activity of your immune system
  • Impairs learning/memory 
  • Increases your risk of cardiovascular disease
  • Increases your risk of cancer
  • Contributes to depression and anxiety
  • AND leads to diabetes/insulin resistance/weight gain

I’ll meet you next week with another article related to sleep. Until then, here is the takeaway lesson for you: 

Sleep is a gift from Allah subuhanawuta’la to improve our health so that we can live our life fully and achieve our best version.