Caffeine vs Suprachiasmatic Nucleus

Sleep is elusive at best, something we look for behind closed doors, in little dark rooms, under special duvets. Some of us prefer hammocks over beds, or beds with millions of pillows over a sack next to the fire, but what about preferences for when to sleep?

Some of you like to get up really early—we call you high achievers, and some of you like to sleep in really late—we call you stoners. But what if our genes had predisposed us to sleep differently and the stoners aren’t stoners after all but high achievers from the opposite end just trying to adjust to a society that won’t let them rest in accordance with their DNA?

Your chronotype denotes your time preference for sleep. Do you like to wake up with the sparrows and jog agaYour DNA has predestined you to be better in the AM or better in the PM, but not both. Now I know why I didn’t want to go to the swimming pool at 5am when I was fourteen. Now I know why it feels so good to lift weights at 10pm at night when no one’s in the gym. This is my chronotype doing its thing.

Maybe you could fake it and live frictionally with your biology, but it wouldn’t be optimal. Being better in the PM has interesting implications for a PT who works silly morning hours all year round. Just when I think I’ve fooled the system and adapted to the alternate chronotype, I have a morning off and sleep-in until ten, after which I stay in bed for a few more hours building forts, reading books, and drinking almond milk. This is where my true calling seems to be.

How would differing chronotypes have aided and abetted our survival as a species?

It likely developed alongside the unfortunate role of sentry, the someone or someones watching over the vulnerable sleepers. Or maybe it wasn’t as organised. But this complimentary ability of our species to split in half and be more vigilant at different times over the course of the night, means there is only a small overlap where everyone is really zonked and defenceless. This would have resulted in a much higher survival rate, and if our DNA’s agenda is to stay alive, it’s likely this was an important arrangement (Check out Matt Walker’s book for more on that).

These days if you stay in bed until midday drinking almond milk, and make it public, you’ll be called a human stain, at the very least.

Sleep dogmas don’t help. Sleeping-in is not a crime, nor is staying up, nor is waking up early, and nor is going to bed before MasterChef starts. We’re all very different, which is a pretty good thing. Be true to your chronotype, if you can, and you will harmonise yourself with some ancient DNA and ultimately a better sleep.

But it’s possible your true chronotype is buried under some bad choices. Too much airport coffee, for example, could be used to self-medicate a PM’er who got up for an early flight. Too many Red Bulls could be used to self-medicate an AM’er working the late shift at the morgue.

But what happens when this self-medication becomes a pattern, and then a lifestyle, and then a necessity?

So, who likes coffee?

Caffeine feels so good because it blocks adenosine in the brain. Adenosine is the bi-product of ATP, our energy currency. Adenosine is the dregs produced by all that daily motion. On waking it begins its slow consumption of the brain until it completely waterlogs your grey matter and the urge to sleep is overwhelming.

Caffeine halts this process by binding to adenosine receptors in the brain and blocking further accumulation of this ‘sleep pressure’. It effectively begins your day afresh, which, of course, affects the natural tendencies of your chronotype. It also puts you out of focus with a larger natural cycle, a cycle that isn’t just yours, but ours as a people, as a planet in this solar system.

This cycle is regulated by an internal clock, right there in the brain, called, a mouthful here, the suprachiasmatic nucleus. This little brain button reacts to external cues like daylight and eating times. It quantifies this data and then establishes something called a circadian rhythm, a pattern with a 24-hour 15-minute shape, a rising and falling of body temperature, hormone control, and sleep/wake states.

Trying to fool this sleep-wake cycle and your internal clock would be like arm wrestling God. No chance. You are a spoke in a cosmic wheel. Your consciousness is predicated by the sun, the big fiery thing that feeds your physical and energetic body. You can’t step out of a process this vast and emerge unscathed. You can picket against gay marriage, but not against your suprachiasmatic nucleus.

Yet we attempt to fool these natural waves every day. We drink coffee and pretend we love waking up early because we live in a society where getting up early and demolishing your day is more honourable than looking after your health. Maybe you’re just better at night. Your chronotype and your suprachiasmatic nucleus are better predictors of your daily capabilities than the next motivational speaker. It’s time to find your natural groove and indulge in these external stimulants for fun, not because you need them to trick your body into focus for a few hours.

It’s hard, but do what you can. Know that you have rhythm, even if you dance like Elaine (Seinfeld reference). When the foamy top layer recedes, you’ll hear the music and remember the steps. Get in touch with yourself. Are you a morning or a night type of hominid? Turn your head to your wrist and listen for your internal clock, maybe just a distant ticking, but it’s there. Sync up with your pattern and superimpose yourself back onto your body and your life.