Little sleep, but no sleep deprivation – what affects the need for sleep?

Most adults need around 8 hours of sleep per night. However, the required amount of sleep is often said to vary between 6-9 hours. What is behind this variation in the need for sleep?

Sleep needs are affected by lifestyle as well as genetic factors

Several complex factors affect the amount and quality of sleep. Well-known factors include the rhythm of the internal clock, nutrition, exercise, and stress. In addition to lifestyle, genetic factors also play a role in sleep. Conversely, sleep itself affects lifestyle, and challenges with weight management can be linked to insufficient sleep.

Sleep deprivation is a condition where a person sleeps too little for their needs. Sleep deprivation causes changes in metabolism and hormone regulation, which can lead to disturbances, for example, in eating behaviors. It’s important to listen to your body, as it is often the best way to avoid sleep deprivation. Understanding your genetics can help you understand how your body works, even when it deviates from the normal.

What to do when your smartwatch tells you that you’re sleeping too little, but you don’t feel tired?

Smartwatches often operate on average population values, but by doing a genetic test, you can set your watch to align with your personal sleep needs.

A rare gene form causes reduced sleep needs

Short sleep is often associated with sleep deprivation, but it does not always automatically mean sleep deprivation. There are so-called short sleep genes that allow certain individuals to manage with shorter 4-6.5 hour nights of sleep. The prevalence of this gene form is still unknown, but it is assumed to be quite rare.

Naturally short sleepers (Familial Natural Short Sleepers, FNSS) possess a form of the DEC2 gene that increases the production of orexin in the brain. Orexin is involved in maintaining alertness, along with regulating appetite and stress reactions, and affects sleep quality. A lack of orexin leads to narcolepsy, while its increased production results in a shorter sleep need. For naturally short sleepers, the higher level of orexin causes a shorter sleep need without the risk of sleep deprivation. These individuals do not suffer from sleep deprivation after short nights like others. The need for shorter sleep seems to be based on orexin’s effect in improving sleep quality.

This DEC2 gene also influences recovery from sleep deprivation and the structure of sleep, such as the proportion of REM (Rapid Eye Movement) sleep and NREM (Non-Rapid Eye Movement) sleep. Recent studies have found further evidence of the benefits of this gene form, as it appears to provide some protection against Alzheimer’s disease. However, this does not mean that the normal sleep need gene form is a risk factor for the disease; rather, it seems that short sleepers have a slight extra protection against Alzheimer’s. 

(iScience. 2022 Apr 15; 25(4): 103964)

(Proc Natl Acad Sci U S A. 2018 Mar 27; 115(13): 3434–3439.)

With the Feel genetic test, you can uncover your genetic sleep needs, circadian rhythm, sleep quality, and many other wellness-boosting characteristics!

Tags: