Skin Science: does clean skin equal clear skin? 🧬
We’re always being told that as long as we ‘wash our face’ or ‘keep our skin clean’, we’ll be fine. Our skin is the largest organ of our body. It’s important we take care of it, and and though skin hygiene is incredibly important, there are other crucial functions at play when it comes to achieving clear and happy skin.
First, it’s important to know that not all bacteria is made equal. We may feel inclined to eradicate all of the bacteria present on our skin, but some are indeed good, while some are bad. They all play individual roles in our skin’s health, with some directly contributing to frustrating issues we find on our skin. Think of our skin as a giant mansion full of bacterias engaging with each other, like a party. It’s essentially a party mansion for bacterium. Up to 1 billion bacteria inhabit 1 square centimetre of our skin.
Pro-biotics
One of the good guys. Pro-biotics are the living bacteria that’s also present in our food such as yogurt, miso and tempeh. Chemical exfoliants like lactic acid are derived from pro-biotics, lowering our skin’s pH to prevent growth of harmful bacteria. Consuming pro-biotic rich foods are a great way to maintain our skin health from within. Try to get at least one serving a day!
Pre-biotics
Another great bacteria to have at your arsenal. These are usually naturally-derived, and play an important role in balancing the microbiome of our skin. Common sources include beets, asparagus, beans, oats and garlic. Show your support for microbial diversity by consuming these healthy foods!
Staphylococcus aureus
This bacteria is the cause of skin infections, meaning we should avoid this one. Spreading from person to person, they can result to irritant rashes, cellulitis, and abscesses.
Cutibacterium acnes
Living up to its name, this bacteria is one of the few directly linked to the skin condition acne. It tends to colonise the commensal flora of the skin, in the pilous follicles and sebaceous glands — which is where we tend to build acne.
What’s the skin microbiome?
Our skin microbiome is powerful, even if it may not look like it’s doing well in terms of appearance. The correlation between ‘beautiful’ skin and a healthy microbiome isn’t exactly understood, but the microbiome is like the barrier of your skin that will self-heal and repair itself without the help of skincare products. The microbiome on our skin sits comfortable at a slightly acidic environment, allowing it to optimise communication between the immune system and the microbiome. Your skin being cool, dry and slightly acidic, is inherently aggressive to bad bacteria. Even our production of sebum — often associated with acne — is microbial. Our skin has a natural defence against bacteria, but this is broken down throughout the average person’s lifestyle.
Protecting the skin barrier: our natural line of defence
A key to healthy skin is to maintain microbiome diversity, although we want to be preferential towards the good guys. Whenever we consume antibiotics, practice excess hygiene (clean our face too harshly or often), use harsh preservatives or have poor nutrition intake, we disrupt our skin microbiome.
Antibacterial soaps kill the good guys as well as the bad bacteria. You don’t want that. Additionally, soaps are alkaline, meaning they disrupt the pH of your skin’s slightly acidic barrier, leaving it susceptible to alkaline-loving pathogens. Environmental factors such as humidity, dryness and heat can also contribute to various skin conditions such as rosacea, fungal acne, and psoriasis. Here are some basic things to remember when dealing with skin issues:
1. Avoid stress and hormonal changes
Your skin is directly responsive to estrogen and testosterone. This is why acne flare-ups during menstrual or pre-menstrual periods are more common. Occurring at any age, it is estimated that about 5% of women and 1% of men suffer from adult hormonal acne, in the form of pimples, whiteheads, blackheads and cysts. Acne is a result of excess oil production that clogs our skin. Sebaceous glands are particularly sensitive towards testosterone, and the more it is present in our blood, the more it triggers our sebaceous glands to produce even more oil. Oestrogen on the other hand, also influences sebum production, but at a very high level can emit the opposite effect by increasing collagen production, hydrate your skin, and support wound healing.
We all feel stress from time to time. This however, produces cortisol, a stress hormone, again leading to inflammation issues like psoriasis. Besides, similar stress-inducing factors such as lack of sleep, anger and increases in blood sugar all contribute to acne.
2. Preventing transepidermal water loss (TEWL)
Hydration inside and outside is both equally important in preventing our skin’s trans-epidermal water loss. Besides from drinking lots of water, it means you should ensure your skin is both hydrated and moisturised. Similar to water and oil, your skin can be dehydrated but oily, or hydrated but dry. Oily skin is usually a consequence of thirsty skin, producing excess oil to compensate dehydration. Wrinkles and fine lines are also the result of TEWL, because when you lack the moisture barrier, your skin elasticity will also start to degrade.
Transepidermal water loss is the process by which water passes from the dermis through the epidermis and evaporates from the skin’s surface.
Although TEWL is an unavoidable process, we can maintain healthy levels of hydration and moisture by overcompensating when the loss occurs. Typically, look for humectant ingredients in skincare that will hydrate your skin, and seal off the hydration with an occlusive ingredient which will in turn, moisturise your skin. Occlusive agents not only seals in moisture, it forms a barrier that prevents any pollutants, harmful bacteria, and toxins from entering the epidermis layer of your skin. When layering on skincare, you want to go with the thinnest to thickest consistency. Water is thinner than oil, and your skin would behave exactly the same as the picture below.
3. Clean your skin — but gently
Did you know that washing your face can be the most damaging step? Besides from making the mistake of over-washing your face (more than twice a day), lots of cleansers contain very harsh ingredients that can strip your face of its healthy microbes. In particular, harsh exfoliant scrubs can cause actual micro-tears in the skin, leaving behind crevices for pathogens to situate and breed. Conventional soap for the skin is a definite no. These are incredibly stripping, targeting both good and bad oils, disrupt the acidic pH barrier, ultimately leaving you with a dry and flakey canvas over time.
As mentioned, our skin is a complex microbiome composing of water and oils, so naturally the best way to cleanse is to use a method that incorporates both. The popular ‘double-cleansing’ method uses an oil cleanser first to strip away harder-to-clean layers like sunscreen and makeup, whilst the second step of a water-based cleanser gets rid of any remaining dirt and pollutants that may still be left behind.
4. Use sunscreen
The ultimate enemy against our skin’s natural microbiome is unfortunately the sun. UV is the primary cause for aging, pigmentation, fine lines and texture is the harmful UVA (think of it as A for aging). 90% of skin’s aging is due to the effects of the sun. Exposure to the sun slowly deteriorates the proteins in our skin, known as elastin and collagen, which helps to maintain our youthful appearance. It disrupts the skin microbiome by changing the balance of microbes, affecting the delicate process of homeostasis. Sunscreen, hats, visors, full-sleeved clothing — these are all useful forms of UV protection you should be making at least one of daily.
At the end of day, our microbiome deteriorates over time and age. It’s important we take care and maintain its diversity in the meantime. While we most definitely don’t need a 10-step skincare routine, we do need to keep hormonal changes in check, prevent excessive water loss, practice gentle cleaning and ensure we use sunscreen daily (with re-application!). Although there are a range of skin issues that can vary from treatment to treatment, this post summarises the most basic principles of a healthy skin microbiome.
