The secret to a good night’s sleep is in our genes

It’s that time of year when students have one thing on their mind – the dreaded e-word! In their focus to cram however, sleep can often wind up neglected, even though it is so crucial to our wellbeing.

Scientists have conducted experiments into sleep deprivation, in which volunteers endured up to 11 days without rest. Symptoms became increasingly serious, with the subjects suffering decreases in concentration, perception and other mental processes. Obviously an impairment in concentration and thinking is not the ideal set-up for sitting exams, so getting some rest is very important.

Obviously an impairment in concentration and thinking is not the ideal set-up for sitting exams, so getting some rest is very important.

When should you rest? Some people are inclined to head to bed nice and early, whereas others enjoy staying up into the morning hours – this is thought to differ because of a certain gene mutation. Your sleep cycles are governed by a natural circadian clock, which controls your sleep with the rise and fall of certain hormones. Melatonin is one of these hormones – it regulates sleep and wakefulness. For most people, melatonin levels start to rise at nine or ten at night. For people who suffer from delayed sleep phase disorder (DSPD), there is a delay, and their levels start to rise at about two in the morning. Scientists studied the DNA of people with DSPD, and found a mutation in a gene called CRY1. This mutation caused more production of a protein that inhibited the body from producing the necessary hormones to transition to the sleep phase of the cycle.

Your sleep cycles are governed by a natural circadian clock, which controls your sleep with the rise and fall of certain hormones.

CRY1 isn’t the only gene to be involved with sleep – there is one that also affects the quality of rest you enjoy. A study of the FABP7 gene in humans, mice and fruit flies all showed the same thing – people with this gene sleep better, with variants causing people to sleep less and wake up more often. It suggests an evolutionary mechanism designed to regulate consolidated sleep, and so any gene mutation creates a detrimental effect.

Another interesting question is why humans sleep at all, and that’s something scientists are still not sure about. Ending the day unconscious and paralysed left our ancestors at risk of attack, so there must have been some evolutionary benefit. Theories include restoration of the body, allowing us to consolidate our memory, and conserving energy (although sleep only saves about 110 calories a night). Whatever the reason, make sure you try to get some rest – we’re built to sleep, and you’ll be doing yourself a disservice if you ignore your bed!