Skin health: stress, sleep and nutrition

Last month, we got to grips with skin health through our Skin Health 101.

We explored the role and function of the skin barrier and some of the key underlying physiological mechanics that can contribute to skin disorders such as dry skin, oily skin and sensitive skin, as well as skin conditions such as atopic dermatitis and the role of the skin microbiome – but we barely scratched the surface.

As the next step in our skin health journey, we will delve into the contribution and influence of lifestyle factors in the context of the skin microbiome, with a focus on stress, sleep and nutrition…

Stress

Stress and associated emotions have been implicated in skin conditions, through what is known as the ‘brain–skin axis’.

Stress stimulates the production of human stress hormones such as cortisol – these can impact the epidermal barrier (the top layer of the skin) by hampering the production of essential lipids and structural proteins, which subsequently leads to increased transepidermal water loss (TEWL) and reduced hydration [1]. These changes can damage the structure of the skin barrier, as well as its immune, antioxidant and microbial defences and its own resident microbiome – it has been shown that certain bacterial species are more prevalent in stressed individuals, which has been linked to variations in skin conditions such as low pH and increased redness and blemishes [2,3].

Clinically, stressed skin may manifest as dry skin, oily skin, sensitive skin, itchy skin, rashes, pale skin, sweating and oedema (fluid retention and swelling). Stress can lead to flare-ups of inflammatory skin conditions such as acne, rosacea, atopic dermatitis and pigmentation disorders, and induce scalp sensitivity and worsen alopecia [2]. The stress hormone cortisol also has the power to accelerate the skin aging process, rapidly enhancing unwanted aging signs such as lines and wrinkles, age spots and skin dullness [4].

In the case of psoriasis, a chronic inflammatory skin disease with both genetic and environmental triggers, stress can exacerbate and prolong the condition by increasing certain immune-related proteins [5]. When it comes to acne, cortisol and other stress hormones that are secreted, in turn, induce secretion of sebum and a molecule known as Substance P – both of which are known to play a substantial role in acne development [6]. Stress has also been shown to be a major aggravating factor of rosacea in patients that experience symptoms such as burning and stinging sensations in cheeks [7].

As the skin provides the first line of defence against the outside environment, stress and an impaired skin barrier can also lead to better penetration of pathogenic microbes and increase vulnerability to infectious skin diseases, such as viral infections, mycosis and impetigo [2].  Maintaining a balanced skin microbiome is also one crucial element to help support the skin and its overall immune system in its protective and regulatory role, as the microbiome can influence skin immune responses [8], but stress has been shown to disrupt the balance of our resident skin microbiota.

Bacteria such as Corynebacterium and Staphylococcus have been found in higher abundances in people who are stressed, with a knock-on effect for skin health and functioning due to links to inflammation and changes in parameters such as skin pH (read more about this here). Using topical cream treatments can restore skin microbiome balance, and has been shown to improve the associated skin changes by reducing redness and blemishes and regulating skin pH [9].

As well as directly effecting the skin microbiome, stress can even worsen skin health and contribute to skin disorders by altering the gut microbiota via the ‘gut–skin axis’ (more on this below!).

Sleep

As humans, we operate according to our circadian rhythm – a powerful internal 24-hour clock that determines our waking and sleep cycles and regulates our normal bodily functions by sending signals to each of our organs accordingly, including our skin [10].

This clock can be disrupted by poor sleep quality, which is common across the world and has been linked to increased risk of many conditions, including diabetes, hypertension and psychiatric conditions. Research has now shown that sleep disturbance also impacts skin disease – this is unsurprising maybe, as sleep is critical for growth and renewal within our bodies [10,11].

Sleep deprivation – also as a factor intertwined with stress – has been associated with increased signs of intrinsic ageing, diminished skin barrier function and poor skin barrier repair as it triggers molecular processes that damage skin structure [10,11,12,13]. Like stress, it has been linked to the worsening of inflammatory skin diseases such as psoriasis and rosacea due to its effect on the skin barrier and skin immune processes [14,15,16], and to acne severity where a connection has been found between fatigue upon waking and increased inflammation [12,17].

The effects are not just skin deep – research has also shown that sleep-deprived individuals are often perceived as less healthy, less attractive and more tired to others, suggesting that we as humans respond to sleep-related facial cues with implications for our social interactions [18]! When it comes to the microbiome, there remains a lack of understanding and data around the direct impacts of sleep. Recent research has however shown that when it comes to the gut, high microbiome diversity is associated with better sleep quality and sleep time, and poorer microbiome diversity is associated with disrupted sleep [19]. It is also interesting to consider the interaction between our resident skin microorganisms and our circadian rhythms – as our skin microbiome communities are known to adjust and adapt to local changes, it’s highly likely that aspects of our skin microbiome are responding to our diurnal patterns (read more here).

Nutrition

The gut appears to have a direct influence on the health of our skin and its microbiome, via an intimate relationship known as the gut–skin axis (read more here).

With 70% of our immune system housed in our gut, it is a key organ for our overall health and functioning, and it also provides a home to billions of bacteria [20]. These bacteria help to digest and absorb our food and support the functioning of the immune system, while also protecting the gut lining from damage and inflammation [21].

It is the effect of the gut microbiome on immune function and inflammation that appears to link the gut most closely to the skin, providing it with the ability to boost or worsen skin health. Beneficial bacteria in the gut microbiome produce substances called short-chain fatty acids (SCFAs) which are anti-inflammatory [22]. Pathogenic bacteria have the opposite effect. If there is an imbalance in these types of bacteria, inflammation can spread beyond the gut and manifest in skin disorders such as psoriasis and acne vulgaris [22,23,24]. These disruptions can occur when gut inflammation is not controlled. Small openings can appear in the gut wall through which particles of undigested food and toxins can escape into the blood stream, in turn reaching the skin and disrupting the skin microbiome – this is known as the leaky gut effect [22].

Looking at some examples in more detail, acne, for instance, is caused by many factors, but the gut microbiome can play a key role in the progression and severity of the disease. The psychological and emotional stress that accompanies acne can impair the gut microbiome, most notably Lactobacillus and Bifidobacterium bacteria, causing the intestinal microbes to produce neurotransmitters that can enter the bloodstream and contribute to skin inflammation [23].

Another example of the gut microbiome influencing the immune response can be found with atopic dermatitis, the most common form of eczema. Here is believed that lack of microbiome diversity during the early stages of life can affect the maturation of innate and adaptive immunity leading to chronic inflammation. Research has shown infants with atopic dermatitis to have reduced gut bacterial diversity and low quantities of Bifidobacterium and Bacteroides bacteria [25].

Nutrition and diet play a role here, as the food you consume is responsible for supporting and shaping the gut microbiome. By eating the right foods, you can nourish your gut, reduce inflammation and support the beneficial bacteria that live there – food that is high in fibre, ferments and probiotics, for example, can provide the perfect nourishment (read more about thishere) and even help combat skin conditions such as acne [26]. However, a diet high in salt, sugar, saturated fat and processed foods containing preservatives and additives has a myriad of health implications, and can promote the growth of pathogenic bacteria and inflammation [27,28].

Explore more microbiome basics in the How it works section of the Content Hub and follow us on Instagram for the latest updates!

References

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