Why do different people need varying amounts of sleep? Does sleep vary as you age?

The fundamental question that everyone has on his or her mind about sleep is how much quality sleep is actually required. Though it is easy to conclude that it’s subjective, the science behind it can neither be ruled out nor fully explained. Interestingly, the study of genetic might throw some light on our sleep quota. We attempt to analyze the different amounts of sleep required by different sets of people, also considering age factor in this blog. 

There is a rule of thumb that adults sleep between 7 and 8 hours, but there is no scientific proof corroborating the point. A research study published by the Sleep and Circadian Neuroscience Institute at the University of Oxford indicated that before the industrialization era, it was natural light that impacted our sleeping and walking times, and that it was referred to as their ‘first & second sleep”. Then electrification in several countries post-industrial era affected sleeping patterns and behavior. A report by the US National Sleep Foundation (NSF) in 2015 recommended that the ideal sleep hours is 7-9 for adults in the age set of 18-64.

Interestingly though the NSF researchers categorized a new group over and above their recommended data set known as “may be appropriate”, that explains the variation now determined between individuals. The Foundation considered these values, and suggested that people aged between 18 and 25 may require sleep hours between 6 and 11 hours per night and 6 - 10 hours for individuals aged between 26 and 64.

Now, why this difference? Besides social constraints such as the need to wake up early for daily commute, Foster came up with two important biological factors as to affecting an individual’s sleep requirements: the biological clock, or technically the circadian clock and a basic principle of sleep regulation, Sleep homeostasis.  The longer time you stay awake, the greater is the sleep pressure, and thus the need for sleep. When you fall asleep, the body feels less tired due to the dissipation of sleep pressure. 

However as there is build up of sleep pressure during the day, and you get increasingly tired, you don’t usually end up sleeping, definitely unintended, due to the biological clock effectively specifying a timestamp of what is a good time to sleep (i.e. night).  You’ll be able to see this set into motion when you move into a new time zone, and the sleep pattern suitably adjusts to the changes in the light cycle.  These body functions, as a result of biological processes, differ from one individual to another due to environment factors including genetics and light exposure. Consequently, our sleep schedule is a variation of several such factors.

Foster adds that several key genes are linked to the biological processes and the associated subtle changes can turn you into either an early bed-goer (an early riser) or a night owl (evening person)who is up all night or until the early hours.

There are many amongst us who are usually evening people, but each set has its own drawbacks. Being a night owl can disturb your natural sleep behavior when you need to wake early for work. If you’re an early bed goer or a lark, then social obligations can interfere in the way.

Foster further explains that most members in a family exhibit ‘Morningness’ and ‘eveningness’. Nonetheless, there is some scope for variation. Both process synthesis and degradation processes in the corresponding gene give way for several points at which even subtle changes can impact the sleeping patterns and habits of an individual.  The rates at which your genes are turned on, the genes produce the proteins and, in turn protein complexes are formed and make their way into the nucleus, deactivate their own genes, and eventually, degradation of those protein complexes occur, in actuality forms a 24-hour oscillation. 

If any changes happen at one or many points in the process, it could affect your genetic susceptibility or genetic predisposition to prefer either lazy morning or late nights. A person’s sleep preferences are modified by the environment, but there is no easy way out i.e. the genes can’t be changed (yet). To come to the point, age factor will change your sleeping pattern, which is also recommended in the NSF reports: it indicates14 –17 hours of sleep over a 24-hour period for newborn babies/infants and just 7-8 hours for people aged 65 and over or senior citizens. Children do require a lot of sleep. 

However, Foster says that not everything is about this simple timestamp. Teens and people in the early 20s’s age bracket would rather prefer to go to bed late and wake later too the result of the changes of hormonal activities. Or in other words, teens exhibit a troubled state of relationship with sleep. Typically, there exists a two-hour difference in the sleep times somebody in the early 20’s/late teens to those in the late 50s to early 60s age bracket. Therefore, if you ask any teenager to wake at 7’0 in the morning, it is equivalent to asking a 50-plus year old to leave the bed at five early in the morning.   

All said and done, only you can gauge the quantity of sleep by listening to your own body or understand its subtle pattern. Do you always need an alarm clock to come out of the bed? Do you require a long time to actually stay awake? Do you probably need a mug of coffee in your hand to stay focused during the day? What behaviors do you exhibit: overly impulse? Unempathetic? Are you experiencing daytime fatigue? Do you have a difficulty concentrating and remembering? All these are symptoms that you are not receiving adequate sleep?

And that, as we know, leads to deprived health condition. Foster concludes that key researches conducted in the area of sleep was one of the greatest achievements of advancement in present-day neuroscience, and that there is a gradual shift from the 80’s all-nighter culture to the need to respect the body and sleep. Let’s us understand that sleep is not a luxury or indulgence, but rather a bodily need important to our survival as we grow and change everything else in our lives. If you think selecting the right mattress can actually buy you quality sleep, then you’re already in the best place to buy a mattress.