Many Americans have a weird relationship with sleep. It’s like we are so busy we resent having to stop and sleep. “I’ll sleep when I’m dead!” is definitely a sentiment I have heard many times. For something so basic, we are really bad at doing it well. According to the National Sleep Foundation, 30-40% of adults reports symptoms of insomnia within a given year, and 10-15% of us suffer from chronic insomnia! This impacts men and women at the same rates and only worsens as we age.
The basics of sleep
Sleep has been divided into 5 “layers” by sleep specialists. But for you and I, there are two main types of sleep: REM (Rapid Eye movement) and Non-Rem sleep or “N-Rem sleep. It would be understandable for us to think of sleep as “rest time” for the brain. But sleep specialists armed with EEG’s and MRI’s have found there is a lot of important things going on at bed time.
N-REM sleep
During the day we see, do, think, and interact with all types of stimuli. Part of the function of the brain is to store all of that information for use later. If you have ever made a short video, you probably did something like this: filmed a bunch of raw video, and then later went back and edited it to make a perfect film and tossed the rest. That’s what N-REM sleep is all about. All of that memory gets stored in a short term holding bin during the day, and then at night your brain edits it and moves the “keeper-memories” into long term storage. If you have ever wondered why it is so hard to remember stuff after a night of poor sleeping now you know!
REM Sleep
Now REM sleep is even more interesting in some ways than N-REM sleep. REM sleep is the part of the sleep cycle where we dream. But what is it all for? During the day, not only are we collecting up lots of information with our senses, but we are also collecting “emotional information”. Some things make us joyous, some things terrify us, others really tick us off. Part of the purpose of REM sleep is to strip away most of the emotional information from our memories. For most of us when we remember events in our past, we can remember that we had an emotion or a feeling, “IE- I was happy at the wedding”, but most of the time we can’t recreate the emotional experience as it happened. That’s probably a good thing. Sleep Scientists are fairly certain that people suffering from PTSD ( Post traumatic Stress disorder” are having a problem with effective REM sleep. These folks do re-experience very intense emotions when certain events come to mind. That intensity is part of the problem with PTSD. Good REM helps us “ let go of emotional content of memories” so we can be more objective about it all. So, if you are a highly anxious person, high quality sleep may be a very important technique for handling those emotions.
Brain hygiene
Now if you were thinking that sleep was the time for your brain to rest and restore itself, you are
definitely on the right track. The brain is a very busy metabolic organ and it creates a lot of mess doing its job. Somebody has to clean it up. That work is done by the Glymphatic system. Never heard of it? Don’t kick yourself, not many have. Scientists have recently discovered how the brain does maintenance which took awhile as the brain sits behind something called the “blood brain barrier”. This wall makes it hard to get stuff in and out of the brain- which is good when it comes to things like infections. The Glymphatic system cleans out the brain and in particular helps to flush things like Tau proteins from the brain. Ever heard of Tau proteins? I bet you have, these are the proteins that build up in the brain and are associated with Alzheimer’s dementia. Here is the kicker, The Glymphatic system does 90% of its clean up function during sleep. If you are chronically sleep deprived, or suffering from poor quality sleep, your brains ability to keep up with hygiene is severely impaired. So, does chronic sleep issues have links to Alzheimer's? It turns out it does! This is the ironic part: The parts of the brain where those Tau proteins build up first, also happen to be the parts that control sleep! As effective sleep becomes less possible , the brain falls further and further behind in cleaning out toxic proteins and so the whole process can accelerate! Pretty frightening to consider.
Sleep and your heart
Your heart starts beating about 22 days after you are created. For most of us it will beat more than 54 million times during our lifespan with out a break. Imagine that! What if you had to do biceps curls one each second of every minute of every day for 80 or 90 years! I’m pretty sure my arm would fall off pretty quickly! So when does the heart rest? It rests when we sleep. Our heart rates and blood pressure drop a lot when we are deep in our sleep cycle. This lets the heart rest and recover for the work of the next day. If your sleep is poor quality your heart is denied that rest! Poor sleep is significantly linked to heart failure, arrythmia, strokes, high blood pressure and heart attacks.
Sleep and your immune function
It’s a germy old world out there. Do you know what keeps the germs at bay? Our immune system! Does sleep impact our immune function. Oh my yes! There are a large pile of studies building up looking at this connection. When we don’t get adequate rest the numbers of our T cells and Natural Killer cells (immune cells) go down! Pneumonia and viral infection rates go up.
Getting vaccinations when you are tired versus rested even has a significant impact on how much
antibodies you make to fight off infections! So, whether you are trying to improve your memory, avoid anxiety, lower your risk of Alzheimer's dementia, trying to avoid heart disease, or just not die of an infection…(whew) making sure you are getting adequate amounts of high quality sleep is important!
If you suspect you are experiencing problems with your sleeping habits, you should absolutely talk to your doctor or a sleep specialist and get it checked out, there are a lot of health gains to be had in making sure your sleep is on point and effective!