Beauty sleep: The science that proves it's real

The desire to look good is a phenomenon that has spanned the ages and crosses cultural barriers. It’s in our nature to want to look our best, and more often than not, looking good means looking youthful. We throw ‘I need to get my beauty sleep’ around like any old-wives tale, but science proves there's more to it than just that.

Deep sleep repairs cells

We tend to sleep in five-stage cycles, which last from 90 – 110 minutes and recur throughout the night. During stages 3 and 4, known as deep sleep, there's a surge in the secretion of growth hormone. Growth hormone assists with the repair and rebuilding of skin cells. There's also an increase in cell production and a decrease in cell protein breakdown.

This means it's important to reach deep sleep to repair the damage caused to your skin throughout the day.

Sleep combats the effects of stress

When we're sleep-deprived, the amygdala becomes more reactive. The amygdala is a brain region that handles emotional processing and increased reactivity adds to stress.

Stress causes our bodies to increase their production of adrenaline and cortisol. These hormones create inflammation and reduce the skin's firmness.

Stress also increases sebum production. Sebum is an oily substance that ensures our skin and hair are waterproof and not dry. In large amounts, it can leave the skin oily, increasing your risk of acne or other skin irritations.

Sleep can reduce the body's stress response and avoid these negative beauty effects.

Lack of sleep damages collagen

Collagen has many roles in our bodies – for example, it’s the main protein in our body’s connective tissues and bones. It also keeps our skin plump, our hair glossy and our nails strong.

Persistent stress throughout the day damages collagen at a molecular level. The longer you're awake, the more damage is caused to collagen. While you sleep, stress-related hormones reduce, allowing your body to produce more collagen. The longer you sleep, the more collagen is produced.

Sleep deprivation damages chromosomes too

Sleep deprivation can also have negative genetic impacts on our ageing process. There's a telomere at the end of each DNA strand, which acts as a cap to protect our chromosomes. These caps play an integral role in protecting our DNA structure from damage, but they can shorten as we age. Stress or inflammation can speed up this shortening.

Good quality sleep can reduce stress and inflammation and slow the ageing process. This can keep us looking younger for longer.

If you struggle to get quality sleep, have a look at our practical tips for a good night’s sleep.

Last updated Tuesday 14 June 2022

First published on Monday 12 September 2016