What if I told you that there is a drug which promotes better concentration, memory consolidation, emotional stability, hormone regulation, a healthy immune system, better energy, protects against chronic diseases, improves your appearance and is completely free? You would quite rightly be sceptical, although sleeping 8 hours a night achieves all of this. Around two-thirds of adults neglect their sleep and sleep less than they ought to which explicitly harms their health and overall development. In a university culture of drinking and all-nighters the effects of this are especially visible.
When talking about sleep it is important to differentiate between rapid eye movement sleep (REM) and non-rapid eye movement sleep (NREM), as each type contributes differently. REM sleep works to strengthen neural connections, helping to build memories, create dreams and stabilise our mood. It also helps you to better understand socioemotional signals, thus allowing more intelligent responses, encourages creativity and builds vast associative networks of information. Sleeping only 6 hours a night robs you of 60-90% of this REM sleep, the consumption of alcohol also works to suppress REM sleep further. NREM sleep on the other hand allows our body to repair and regrow tissues, and strengthen the immune system. A deficit in either type of sleep will cause a brain imbalance.
Sleep is absolutely pivotal when it comes to learning and developing memories, which is of particular importance for university students. In fact, a nap before a memory test can boost your ability to learn by around 20% as sleep works to restore the brain’s capacity for learning. Even a 20 minute nap would help with this. If you pull an all-nighter and don’t sleep after learning something, you lose the chance to consolidate that information. For this reason studying whilst sleep deprived is somewhat futile as it means that information is forgotten more quickly than if well-rested.
This is where the importance of the last two hours of an 8 hour sleep is stressed, as these hours are the richest in ‘sleep spindles’, which are short bursts of electricity generated from stage 2 NREM sleep. These work to move memory from the hippocampus (short-term memory storage in the brain) into the cortex (long-term storage). Additionally, these sleep spindles place a disproportionate emphasis on the parts of the brain that worked the hardest during the day, and improve the efficiency of sleep mechanisms.
It is when it comes to physical health that the consequences of consistently insufficient sleep become most visible, although it may not be especially obvious as you do not know how sleep deprived you are when you are sleep deprived. In praxis, should you sleep consistently for only 6 hours a night for a week, your wakeful performance would be impaired by as much as being awake for 24 hours straight. For comparison, after being awake for 19 hours, you are as incapacitated as someone who is legally drunk (0.08% blood alcohol). It is for this reason that drowsy driving is the number one cause of car crashes, outweighing the damage caused by drink and drug driving, although these instances should also by no means be neglected. Additionally, shorter sleep is also associated with a 45% increased risk of developing coronary heart disease, doubles the risk of cancer, and increases the chance of contracting type 2 diabetes. It also suppresses leptin (the chemical that reduces hunger) and promotes ghrelin (the chemical that promotes hunger), which results in an increased calorie consumption, with an average of 330 extra calories per day when sleep deprived across a study. Should you prioritise sport it is also worth considering that if you sleep for less than 8 hours, the time until physical exhaustion drops by 10-30%, aerobic output is significantly reduced and risk of injuries are increased. Your testosterone levels will also drop significantly, matching that of someone 10-15 years older.
Wakefulness produces amyloid protein deposits and other metabolic waste in the brain that is cleaned whilst asleep by the brain’s glymphatic system, a failure to sleep sufficiently significantly increases the chance to develop Alzheimer’s disease in later life. Said simply, wakefulness is low-level brain damage and sleep is the treatment. A night of 4 hours sleep reduces the count of natural killer cells by 70%, which fight free radicals in the body, such as cancer cells. In regard to the COVID-19 pandemic, sleep is once again vital in our body’s response as sleep boosts the immune system against fighting sickness and responding to vaccines. Across years of subpar sleep, the consequences quickly become rampant. Therefore this article serves to stress the importance of sleep, especially for university students, as a medium for improving physical and mental health in a particularly turbulent time. If you would like to further explore this topic I would implore you to read ‘Why We Sleep’ by Dr Matthew Walker, which served as the inspiration for this article.