Melatonin is a naturally occurring hormone secreted from the Pineal gland in the brain. It’s production is triggered by factors within and outside of the body, and it’s primary function is to prepare the body for good quality sleep.
Internally, production and secretion of melatonin is linked with circadian rhythms, the underlying processes that drive sleepiness and wakefulness. External factors, however, have the capacity to influence melatonin production and it’s association with the internal body clock.
Diminishing light is a primary trigger for melatonin production to occur. Primally, human’s are wired to sleep in the dark and wake in the light. But the existence of such ‘normal’ sleep:wake cycles have been challenged and stretched since Edison’s invention.
Artificial light has allowed us to extend ‘daylight’ hours, which appears great for business, socialising and general productivity. The physiological downside is a harsh wake-up call to our system that would otherwise be hormonally preparing for rest and recuperation.
In particular, back-lit gadgets are associated with greater suppression of melatonin than other kinds and colours of artificial light.
The current consensus is that two hours of gadget use or television before bed decreases melatonin by around 20%.
But I’m tired and have no trouble falling asleep as soon as I flick it off…
Here’s the thing. You still produce melatonin. You’re wired to do so at night. So there is no issue with entering the initial stages of sleep. But sleep is a process of phases, all of which need to be completed in sequence to fulfill it’s many duties. So the effect of gadgets on sleep is a bit like this:
Your mechanic services your car, but instead of giving you five litres of oil, she only gives you four.
The oil burns out before it should, and your car grinds and splutters it’s way to the next top up. Over time, your vehicle begins to resemble one that is much older, with traits including:
Increased fuel consumption – high ghrelin levels associated with sleep deprivation leave you craving carbohydrates.
Grinding and grating – pain sensitivity is amplified when sleep quality is poor.
Breaking down – mechanical and cognitive function during the day are compromised with lack of sleep.
Hard to start – excessive priming requirements (caffeine, cold showers etc) are indicative of chronic sleep loss.
But I’m not sleep deprived. I’m in bed for 8 hours a night…
Many people would not consider themselves clinically sleep deprived. We must consider sleep quality on top of quantity. Microdisturbances to sleep can occur without awareness, disrupting the sleep process. Waking, restlessness, pain, and physical time in bed are also qualitative factors that impact sleep quality.
If you suffer regularly with tiredness, mood or general unrest, take a look at your activities in the couple of hours before bed. Good hormonal preparation may carry you into long unchartered sleep territory and fulfill the processes of rest and recovery for which it was intended.