The science behind beauty sleep

A full eight hours of shut-eye may be the closest humans can get to the fountain of youth.

But is there actually any science behind the idea of getting beauty sleep? According to Dr Unnati Desai, national GP lead at Nuffield Health with a special interest in dermatology, there is evidence that getting enough sleep - combined with other factors - impacts the way we look each day.

Sleep supports holistic health

In modern society, we have all been guilty of deprioritising sleep at some point.

"We're all able to relate to the impact a bad night's sleep can have, and yet it's normally one of the first parts of our routines to be sacrificed whenever life gets chaotic. First and foremost, it's incredibly important to understand that sleep is so much more than just a numbers game. Our quality of sleep impacts our overall wellbeing, including our physical, mental, and cognitive health," she said. "During sleep, the body undergoes regeneration and repair, which helps to support every system within our bodies. It's crucial to prioritise getting uninterrupted, quality sleep on a daily basis in order to reap the most health benefits."

Sleep encourages growth of hormone production

We tend to sleep in five-stage cycles, which last from 90 - 110 minutes and recur throughout the night.

"During stages three and four, known as deep sleep, there's a surge in the secretion of growth hormone. Growth hormones assist with the repair and regeneration of all cells, including skin cells. There's also an increase in cell production and a decrease in cell protein breakdown," the expert explained. "These growth hormones are important for the production of collagen and elastin, which are positive components of the dermis to create plump, smooth skin which is well hydrated and has a natural glow."

Lack of sleep increases cortisol levels

Cortisol is the hormone that kicks in our natural "fight or flight" mechanism, which means the body is always on high alert. During sleep, we see a decrease in cortisol, the stress-related hormone, in the body.

"A lack of sleep, unfortunately, does the reverse - it increases the cortisol levels in our system. This, in turn, can have a negative impact on both our skin and hair, and can be the cause of some of the most recognised skin symptoms from sleep deprivation," noted Dr Desai. "Collagen breaks down naturally, however, cortisol can accelerate its breakdown further, resulting in poor quality skin with fine lines, dullness, and dehydrated skin - this can cause dullness around the eyes.

"Elevated cortisol levels can also impact our blood vessels, causing them to dilate which can exacerbate the darkening of the thin skin under the eyes. But it doesn't just stop there. Cortisol also stimulates oil production in both the skin and scalp, which can result in acne breakouts, as well as cause greasy hair."

Implement a night-time routine

While getting enough sleep is key, it's also smart to consider your evening skincare routine too.

"Cleansing your face before bed will remove any pollutants that your skin comes into contact with throughout the day, such as make-up or environmental particles. It's always a good idea to remove your cosmetics fully before you wash your face to ensure your cleanser is more effective on the skin," she added. "If you're looking to prep the skin before sleep, I would also recommend using a medical grade face wash with alpha hydroxy acids (AHAs) or beta hydroxy acids (BHAs) which will gently exfoliate the skin and stabilise the oil-producing pores. A non-alcohol toner will also help to refine the pores by stripping the natural oils from the skin."