Why We Sleep – #Lack of Sleep (2)

Woman sleeping with had on table in front of her books and computer
Photo by Andrea Piacquadio on Pexels.com

Hey there, good to have you here :). We are in the midst of a series on sleep based on the book Why We Sleep by Matthew Walker. If this is your first visit to my blog, welcome! If you want to catch up on older posts from the series, you might want to go back to the Introduction and start from there. For those of you who have been following the series all along, welcome back 🙂

I recently wrote about the consequences of sleep deprivation. However, I mostly concentrated on short-term effects. Now, I want to give you a glimpse of possible long-term and more profound effects that a lack of sleep can have. So let’s pick up where we left off and dive right in…

Unhealthy Sleep, Unhealthy Heart

…is how Walker starts off his chapter on the topic. Sleep deprivation does not only lead to drowsy driving, emotional irrationality or poor psychiatric conditions, no, it can also have substantial effects on our hearts. A 2011 Study with a few hundred thousand participants across different countries, ages, races and ethnicities has shown that „short sleep was associated with more than a 45 percent greater risk of fatal and non-fatal coronary heart disease within seven to twenty-five years from the start of the study.“ Further studies support this assumption. Even if one takes other risk factors into account such as smoking or body mass, „the relationship between short sleep and heart failure remains strong.“

Especially in midlife, and that may come as a surprise, getting enough sleep seems to be more important than ever. In fact:

Adults forty-five years or older who sleep fewer than six hours a night are 200percent more likely to have a heart attack or stroke during their lifetime, as compared with those sleeping seven to eight hours a night.

Matthew Walker, Why We Sleep

Walker also admits that this is unfortunate in a way since midlife is also the time when we raise kids and work long hours in our jobs, hence, sleep might not be our highest priority even though it is especially important during that phase.

To not only throw facts at you, let me summarise the process behind the assumptions: in a nutshell, sleep deprivation causes high blood pressure which can then lead to heart failure, stroke or kidney failure that then causes death. one major problem is that short sleep does not only cause high blood pressure but also harms, narrows or blocks the blood vessels that go straight to the heart. However, those vessels are supposed to be „clean and open wide“ at all times. So you see, high pressured blood streaming through narrow or even blocked blood vessels is really not the best of combinations.

Diabetes and Weight Gain

Short sleep also has an impact on our diet, because „the less you sleep, the more you are likely to eat.“ Sounds familiar? To me it does. In fact, I experienced it just this morning. My son kept me up from 2 to 3a.m. last night (I think he is teething) and I just don’t seem to get enough or find the right food to fulfil my hunger. I am tired and I feel exhausted and I am hoping food will help to recharge my energy reserves but it doesn’t. Have you ever had that? I hate that feeling. By the way, I have had similar reactions when I was tired at night an about ready to go to bed, and all of a sudden I felt all kinds of food cravings…

Back to the root of the matter: a lack of sleep can cause you to eat more than you need. Longterm effects can be type 2 diabetes, weight gaining or even obesity. Here you see why:


When it comes to diabetes, sugar is the key word. Not only in your food but especially in your bloodstreams. Constant high levels of blood sugar can – and at some point definitely will – harm „the tissues and organs of your body,“ it can attack your health and even cause and earlier death. The damage a high blood sugar does can show in many different ways, however, a very common consequence is for people to develop type 2 diabetes, which not only limits your life’s quality but also usually demands a very costly treatment and furthermore can shorten people’s lives.

Weight Gain and Obesity

So if we are likely to eat more when not sleeping enough it is not surprising that we are also very likely to gain weight. In fact, studies have shown that participants just wouldn’t feel satisfied by food when they did not get enough sleep. This is due to two hormones that regulate our appetite: leptin ist the „I am full“-hormone and ghrelin is the „I am (still) hungry“-hormone. Sleep deprivation causes for those two hormones to get out of control. The bummer is, it is not just your „I am full“-signal missing but also your „I am (still) hungry“-reminder constantly nagging, without ever feeling satisfactory full. That not being enough, if you sleep less, you will also have less energy, thus, you are likely to exercise less which in turn is counterproductive assuming and knowing that most people eat more when they do not get enough sleep. And on top of that, you do not just eat more, but, as studies have shown, most people have cravings for sweets, salty snacks and carbohydrate-rich foods. So I guess we don’t need to argue anymore that:

Inadequate sleep is the perfect recipe for obesity: greater calorie intake, lower calorie expenditure.

Matthew Walker, Why We Sleep

A last note on this: if you try do loose weight but don’t get enough sleep while dieting, you are likely to loose muscle mass, not fat (which is probably not what you want). This is because the body is holding on to its fat reserves when sleep becomes less. If, on the other hand, you are getting enough sleep, your body is willing to give up the fat and is happy to retain the muscle mass.

Now that you know the relation between sleep deprivation and obesity, there is good news as well: getting enough sleep (again) can repair the damage that a period of short sleep might have caused.

Immune System

Last but not least: Short sleep has an influence on our immune system! Have you ever wondered why you not only feel like sleeping all day long when you are sick but you are actually able to do so without affecting you night’s sleep? This is because sleep is strengthening our immune system. So when we are sick our „body is trying to sleep itself well.“ However, this is a two way street. If we do not get enough sleep, our immune system suffers from that and is weakened.

Sleep as a Warrior
Sleep fights against infection and sickness by developing all manner of weaponry within your immune arsenal, cladding you with protection. When you do fall ill, the immune system actively stimulates the sleep system, demanding more bed rest to help reinforce the war effort.

Thus, if you reduce your sleep (even for just one night), you are weakening if not harming this warrior inside of you and your immune system is more receptive for diseases. That surely goes for the flue or a cold, but scientists have also found evidence that sleep disruption can weaken our cancer-fighting immune cells. Studies have shown that there is a link between sleep deprivation and some forms of cancer. I do not want to bore you with the complex details but in case you are interested, try to get ahold of the book and check out chapter eight.

Sleep disruption may therefore increase the risk of cancer development and, if cancer is established, favor its rapid and more rampant growth.

Puh, this is kind of shocking, right? How do you feel about it? Do you prioritise your sleep (enough)? I really hope that people, politics and governments are going to pay more attention to their and our sleep very soon. Until then, each and every one of us can start right here and now and pay more attention to his and her very own sleep.+++

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