Sleep is critical to your overall health and survival. It serves to maintain important processes like3,4:

  • Your brain reorganising and recharging itself and removing toxic waste by-products that have built up during the day. Sleep allows your nerve cells (neurons) to communicate and reorganise leading to healthy brain function. It improves memory recall and reduces mental fatigue.
  • Allowing your body to restore itself. Sleep promotes repair and growth of your cells leading to muscle repair, protein synthesis, tissue growth and hormone release.
  • Energy conservation. Sleep allows you to reduce your energy requirements by spending time functioning at a lower metabolism.
  • Supporting emotional stability. Your brain activity increases in areas that regulate emotion while you sleep, helping to maintain your emotional health.
  • Weight maintenance. Sleep helps control the balance of hunger hormones like ghrelin (increases appetite) and leptin (increases the feeling of being full/satisfied after eating).
  • Proper insulin function, improved immunity and heart health.

Your body cycles through 4 stages of sleep. The cycles occur several times during the night for different lengths of time. The stages repeat about 4 – 5 times during a sleep period of 7 – 9 hours. Stage 1 occurs as you transition from wake to sleep. Stage 2 involves light sleep. Your brain prepares to enter deep sleep during stages 3 and 4. Deep sleep is restorative – where your body builds up energy and repairs cells, tissues and muscles. It allows you to feel awake and refreshed the next day.3,4

The recommended amount of sleep needed depends on your age. Adults between the ages of 18 to 60 years need 7 or more hours of sleep. People aged 61 – 64 years need 7 – 9 hours, while people 65 years and older need 7 – 8 hours.3

Concepts of aging1,2

Scientists have described 2 different concepts of aging: chronological aging and biological aging. Chronological aging is the amount of time that you have lived since your date of birth. Biological (or cellular) aging, on the other hand, occurs as you accumulate damages to the various cells in your body over your lifespan. This gradual accumulation of damage leads to changes in the molecular machinery of your cells e.g. build up of DNA (deoxyribonucleic acid) damage, shortening of the ends of your chromosomes (telomeres), mitochondrial (a small structure found in each of your cells) energy production, changes to the way proteins are produced, and eventual cell function failure. This causes your cells to die or permanently stop dividing (also known as cellular senescence).1,2

Insomnia, sleep disturbances, and sleep deprivation are associated with premature aging and changes to your cells that mimic/resemble aging.1,2 Learn about insomnia5

Hallmarks (distinctive characteristics) of aging that insomnia or sleep deprivation has an impact on.1,2

Shorter telomere length. Telomeres are the protective endcaps of your chromosomes. They are made up of DNA and proteins and serve to protect your genetic information from damage. Each time a cell divides, telomeres shorten a little bit. When they get too short, the cell can no longer divide, and it dies. Telomeres are thus considered a marker of cellular/biological aging. Studies show that insomnia is associated with shorter telomere length.1,2
DNA damage. Damage to the DNA within your cells often occurs but is usually repaired by enzymes that respond to a damage signal, then quickly remove and replace the damage. Short-term sleep loss and interrupted sleep can cause the damage to accumulate by increasing energy (metabolic) demand or interfering with the ability of your cells to effectively repair the damage.1,2

Epigenetic aging. Just about every cell in your body has the same DNA blueprint, but they don’t need all of your genes switched on all of the time. A chemical marker or switching tool known as methylation is responsible for locking genes in the “off’ position. As you get older, some parts of your genome (set of DNA instructions in your cells) can become methylated, and others less. Depending on what the affected genes do, changes in methylation could cause your cells to accumulate damage and age faster. A study found that women with sleep disturbances experience accelerated biological aging.1,2,6

Cellular senescence. Telomere shortening or activation of cell stress and DNA damage pathways cause cells to stop dividing and functioning normally. Accumulation of these non-functioning cells activates an inflammatory response and speeds up aging. Scientists have found increased biochemical markers of the inflammatory response in older, postmenopausal women who report symptoms of insomnia, suggesting that short sleep duration can lead to accelerated aging.1

Effects of poor sleep/sleep deprivation on your facial appearance7,8,9

Poor sleep and short sleep duration can affect your appearance – causing more wrinkles/fine lines, darker circles under the eyes, paler skin, redder eyes, more swollen/puffy eyes, sagging eyelids, hair loss and damage, and more droopy corners of your mouth.7,8

As part of your body’s repair process, your skin makes new collagen when you sleep. Collagen prevents sagging of your skin. More collagen means that your skin is plumper and less likely to wrinkle. If you only get 5 hours of sleep a night, you could develop twice as many fine lines than if you slept for 7 hours. Your skin also becomes drier, which makes the lines more visible.7

Your body boosts blood flow and nutrients to your skin while you’re sleeping, giving your skin a healthy colour/glow. Poor blood circulation caused by insufficient sleep can make your skin look dull or pale, cause dark circles to form under your eyes and weaken/damage your hair.7,9

Adding 1 – 3 more hours of sleep (if you’re getting less than 6 hours per night) can lead to an improvement in your appearance in as little as a day.7


We’ve created a booklet filled with useful tips to help you manage your insomnia.5

In preparing this article, every effort has been made to provide an objective overview. The content contained in this article contains medical or health sciences information as per cited articles for public information. The content of this article has been initiated and is brought to you by Sanofi South Africa.

  1. Carvalhas-Almeida C, Cavadas C, Álvaro AR. The impact of insomnia on frailty and the hallmarks of aging. Aging Clin Exp Res 2023;35:253-269.
  2. Carroll JE, Prather AA. Sleep and biological aging: A short review. Curr Opin Endocr Metab Res 2021;18:159-164.
  3. Nunez K, Lamoreux K. What is the purpose of sleep? 20 June 2023. Healthline. Available online at [Accessed 05 July 2023].
  4. Eugene AR, Masiak J. The neuroprotective aspects of sleep. MEDtube Sci 2015;3(1):35-40.
  5. Tips to help you overcome insomnia and get the sleep you need. Patient resource. Sanofi. MAT-ZA-2100751-1.0-07/2021.
  6. Smith B. What is epigenetic ageing, and can we control it – or even reverse it – with diet and exercise? 30 November 2022. ABC Health & Wellbeing. Available online at [Accessed 05 July 2023].
  7. Jacob S. The truth about beauty sleep. 19 November 2015. WebMD. Available online at [Accessed 05 July 2023].
  8. Sundelin T, Lekander M, Kecklund G, et al. Cues of fatigue: Effects of sleep deprivation on facial appearance. SLEEP 2013;36(9):1355-1360.
  9. Breus MJ. Does sleep help you look younger? 22 November 2020. Psychology Today. Available online at [Accessed 05 July 2023].