Sleeping, Hormones and More of that Evolution Thingy

So my last entry introduced some of my thoughts on evolutionary eating. I have a lot more on that topic and promise to introduce more details, but I wanted to also dive in to the second prong of that change and it was around sleep.

When I was a kid, I had a nice early bedtime that I hated. In general, we'd go to bed around 8pm during the school year, and many nights I'd turn on my radio and hope for the luck of tuning in some radio station from Quebec so I could listen to French talk radio. If I couldn't tune that in, my fall back was always the Doctor Demento show that played every night on a local station outside Boston. I'd lie in the dark of my room and fall asleep to the radio I kept quiet enough that my parents never knew I was staying up late-- but it never worked, I'd always fall asleep anyway.

As an adult, sleep started to transition almost to a luxury-- I'd sleep when I could (and relish in it), but it could be traded for extra hours to get work done, hang out with friends, clean the house, or just plain stress out about daytime hours. Right around the point where I was getting ready to run the Boston Marathon I was at one of my most sleep deprived states in my 35 years. Work was crazy and most weekday nights my team was working until 1am and back at our desks at 7am. In the downtime, I'd try to untangle my brain but more and more often I had this sense of panic that bordered on paranoia. The sleep exhaustion was taking a toll on me I didn't know how to explain. Now I do.

Human bodies exist in a state of balance or an equilibrium we call "homeostasis." Our bodies, whether we are aware of it or not, are constantly playing this regulating game to keep us in this state of equilibrium. That game involves lots of hormones and biochemicals inside the body that respond to changes in environment. Probably the most familiar pair of these regulators are insulin and glucagon that regulate blood glucose. When blood has too much glucose floating around the hormone insulin springs into action and starts storing the excess glucose. When blood has too little glucose, the glucagon visits those same storage sites and pulls some glucose back out and puts it back into the blood. So these two hormones work in conjunction with each other to keep blood sugar in homeostasis. Follow? Cool.

Turns out there are a bunch of these hormone (or biochemical) pairs, that regulate a bunch of functions in similar ways. The ones that I started to really poke at were serotonin and melatonin. The reason I started really coming back to this one was an observation I had made-- the more tired I was, the more depressed and paranoid, right? Already told you that... not news. But the observation was that if these two hormones were in a homeostatic pair, maybe there was something to that biochemically-- I mean, the defacto treatment for depression and paranoia these days are called "selective serotonin reuptake inhibitors (SSRIs)" that include brands like Prozac, Paxil and Zoloft. So if the drug companies were treating depression and paranoia by futzing with the balancing pair to the sleep hormone melatonin (and the natural supplement all the tired folks are buying at the local drugstore), maybe this really was something real. I dug deeper (remember we are in a rabbit hole).

What the heck is serotonin anyway, and why are people inhibiting its reuptake. Um, and what about the initial uptake-- why are we doing it a second time?! My head was swimming, so let's start from the top.

Serotonin comes from the gastrointestinal tract and its main role is to control things like appetite, mood and anger. But serotonin also plays a role in managing memory, aggression, sexual behavior, cardiovascular activity, respiratory activity, motor output, sensory and neuroendocrine function and perception.

Melatonin, on the other hand, is synthesized in the pineal gland of the brain and its job is to regulate the body's circadian rhythm, as well as do a few other fancy things like protect mitochondrial DNA. The protection mechanism of melatonin is often referred to as a "powerful antioxidant" when you try to buy it at the drugstore. (Antioxidants are what protect us against those "free radicals" that apparently come into our bodies and cause mutations. So protecting cellular DNA is good stuff.)

So now you are wondering the obvious-- what makes these two things related? What homeostatic balancing act goes on between these two things-- they seem so totally different from each other. The link is that serotonin eventually gets converted into melatonin. Both serotonin and melatonin (along with all the other hormones in the body) work with their respective "receptors." The receptor binds to the hormone and allows it to be expressed. In the example I talked about SSRIs, drugs like Paxil are introduced to prevent the serotonin from being bound to their receptors and therefore expressed. In essence, this leaves someone taking an SSRI awash in excess serotonin that is never able to be expressed.

There are a few reactions your body has to a high serotonin level-- most notably is an increase in cortisol and adrenaline. These two hormones are the basis of the "fight or flight" instinct. The more serotonin floats around, the higher your fight or flight chemicals. The way to prevent this reaction is to allow for the expression of serotonin that eventually leads to conversion to melatonin and allows for the expression of that circadian rhythm and sleep. An interesting side note here-- unmedicated depressed people often talk about wanting to sleep-- this is a side-effect of this very process-- the serotonin present in that mood-state is looking for conversion to melatonin via its receptors. In turn this conversion to melatonin and therefore natural sleep lessens the serotonin and makes the person, literally, happier.

So here I am prepping for the Boston Marathon. I am exhausted, literally. Which leaves me with a lot more serotonin than my body can convert. See, it takes about 2 hours of darkness before the body can start to produce melatonin, so when I was getting around 4-5 hours of sleep, I was really only getting some 2-3 hours of serotonin to melatonin conversion. By hanging out at my desk at the soft glow of my laptop, I was preventing that process from starting. Which in turn was allowing my serotonin to elevate over time, which was kicking on my cortisol and adrenaline responses and I was getting agitated and paranoid and depressed. Throw in the long runs on the weekend which naturally produce a stress-response of cortisol and adrenaline and things were looking kind of messy.

I needed to sleep.

Fast forward to now. I've been playing around lately with timing sleep. If you think about it, it really wasn't until recently that society as a whole stopped living life by the rise and fall of the sun. In essence, even if we wanted to, we couldn't affect that serotonin-melatonin game all that much-- it got dark at night whether we chose to give into it or not. We could sit by a candle or a camp fire, but we weren't able to bring day into night like we can today. At night, when the sun went down, that conversion just sort of happened and like it or not we all got sleepy and crashed and the next morning when the sun came up our serotonin was low, our cortisol was low, our adrenaline was low and we were ready for a new day.

Now I am totally simplifying all of this. I am calling this an introduction, because this stuff actually ties into the whole insulin-glucagon homeostasis game too, but we'll get there over time, I promise. The point of this post is to introduce the whole idea that evolutionarily we have a nightly reset switch-- when it gets dark, your body naturally wants to start that conversion process. It's why 8 year old me lying in the dark listening to Doctor Demento hoping my parents didn't realize I was still awake never stayed awake very long-- the darkness kicked all this stuff off and eventually I went to sleep. When I grew up, since I didn't just hang out all sneakily in the dark anymore and could keep the lights on, the sleep never came and the paranoia, anger, sadness, stress, what-have-you mounted. By re-establishing that lights-out when it got dark, I got, biochemically, happier and less stressed. Sure I was feeling more rested, but it wasn't about feeling rested, it was about that reset switch that my body had evolved to use finally being thrown. And yes, I still sneak my radio (or my ipod) into bed with me and listen a little while the whole darkness thing kicks off. One day maybe Doctor Demento will start streaming audio or podcasting or something so I can listen again and drift off to sleep singing songs about frontal lobotomies.