What’s up everybody? It’s been a while. Hope everyone’s enjoying the holidays.
I just read an incredible book indicting irregular sleep as a major cause of virtually every major degenerative disease–diabetes, cancer, obesity, cardiovascular disease, etc. So today I’m going to do something a little different. I’m basically going to use this book as my only source and explain what I got out of the thesis. The book is Lights Out, written by T. S. Wiley. This book turns all the traditional ideas on nutrition up-side-down and gives a really comprehensive take on why we have so many health problems.
This is complicated, but there is some golden information here. The basic idea is this: we’re living in the summer all year round and sleeping irregularly, with two consequences. Our bodies are preparing to the winter (by storing fat among other things), and our out-of-whack hormones are preventing our bodies from staying healthy.
Clearly, artificial lighting brought revolutionary changes in the habits of man. The ability to choose when light is available is unnatural, and so we have confused our bodies–which have spent thousands of years researching (evolutionarily speaking) how to regulate themselves in the light and dark.
I mentioned the year long summer. Here’s the idea: because our eyes see light all day long, our bodies think it is summertime. Let’s unwrap this. The summer is the only time of the year when lots of fruit and vegetables are readily available. Furthermore, given the impending winter, our body knows that famine may be on the horizon. Our body craves carbohydrates (fruit and vegetables) because there might not be any later on, and eating all of these carbs causes an insulin spike, leading to the storage of fat.
Evolutionarily speaking, fat storage is a great way to get ready for the winter, but of course there are some problems with this system in the modern era. The barrage of insulin all year long leads to insulin resistance (type 2 diabetes), not to mention obesity.
This also impacts our cholesterol. Our bodies “dump the extra sugar into cholesterol production, which will keep cell membranes from freezing at low temperatures” (p. 20).
So our constant summer leads to diabetes, heart problems, and obesity. What else?
The ability to be awake and sleep whenever we damn well please (let’s call this sleep irregularity) leads to a number of other problems.
Let’s talk about the hormones cortisol and melatonin, which are basically opposites. We produce cortisol when we are awake (and lots of it when we are stressed) and melatonin while we sleep. Cortisol helps us survive when we are under attack by making us freak out and go crazy, while melatonin helps us chill out, rebuild, and get healthy.
Do you ever wake up in a complete fog? That’s because your melatonin hasn’t been able to fully go through its cycle. Indeed, by sleeping irregularly and at the wrong hours, we never allow melatonin to fully do it’s job. Melatonin aids white cell immune function, and it is the most powerful antioxidant (think cancer prevention) we have (90-91).
Cortisol, on the other hand, mobilizes blood sugars and leads to type 2 diabetes, is correlated with stress, and suppresses the immune system (94, 157). Normally, high cortisol levels should be a rarity, but if you aren’t sleeping on time and in the dark, your cortisol levels probably aren’t going down enough or at all.
Having chronic high cortisol and low melatonin is terrible for your health. It is connected with cancer and immune system problems.
Lack of sleep can even lead to depression and other psychological ailments. Melatonin is involved with regulating seratonin levels; given the right amount of melatonin, seratonin should go down. But when seratonin levels stay high because of low melatonin, dopamine levels stay low. Light’s Out somewhat controversially argues that seratonin ends up making you inhibited while dopamine is what makes you happy (101, 104-105). Good sleep is great for mental health.
Our bad sleeping habits cause psychological problems, cancer, chronic stress, fatigue, diabetes, heart problems, and obesity. What’s the prescription?
We need to sleep in the dark, sleep regularly, sleep early and sleep for more hours. In the summer, sleeping for only a few hours isn’t terrible. But in the winter, sleeping at least eight hours is a must. You should sleep in the dark, as even very small amounts of lights can throw your body’s hormone regulation off. It is also vital do be awake as much as possible when there is light out; being out in the sun is great for you. There is a lot of research that shows sleeping from ten to six is optimal for proper hormone regulation. Also, sleeping at the same time every night is more important than sleeping for more hours.
It might be tough to maintain a perfect sleep schedule, but there’s just so much going on here it’s hard to ignore the importance of good sleep.
Congratulations if you made it to the end! That was intense. Happy holidays everybody.