The Science Behind Skincare Ingredients
Like many during lockdown, spending more time with myself made me even more conscious about all facets of self-care. Skincare was something I always knew about but I never actually invested in it because I viewed it as unnecessary and expensive when my skin was doing okay. Saying that, I didn’t exactly nourish the skin on my face properly (if you look at one of my old blogs you’ll see that I used to use body lotion for my face 🤦🏾♀️) and the older I get, I know I have to start at some point or it’s a slippery slope to spending even more money on expensive treatments.
I have to give the skincare gurus their props because as soon as lockdown started, I was hooked on curating a personal skincare routine just from watching a few before and after/routine videos. Before this I had already incorporated using an SPF every day and the difference was incredible, so it had to get better right? Being the studious soon-to-be scientist that I am, it was a must that I researched what all these products were actually going to do to my face, before buying them. Below, I’ll breakdown 4 ‘must have’ products that every skincare brand/guru recommends, based on their scientific efficacy and effectiveness.
Let’s start with the composition of the skin. It’s the largest organ of the human body and among various functions it mainly acts to protect our internal organs from the outside environment. The skin is composed of three main layers: the epidermis, the dermis and the hypodermis (1). Most products have to be absorbed into the dermis to have a beneficial effect on the outermost layer of the skin.
Over time, our skin is subjected to a myriad of environmental pressures such as pollution and ultraviolet (UV) radiation in addition to physical injury and possibly internal dysfunctions, which all contribute to a deterioration of skin health and the onset of skin conditions such as cancer (2,3). One could argue that it’s just as important to protect and take care of your skin as much as the rest of your body.
Hyaluronic Acid: The Skin Hydrator
Also known as hyaluronan or hyaluronate, HA is naturally made by the body. It’s essentially a sugar with components - such as acid and amino groups - on its chemical structure which help the compound carry out its important function in various tissues and the skin. 50% of the all the HA present in the body resides in the skin and its ability to hold and retain almost 1000x its weight in water (1 g of HA can hold 6 L of water) makes it a fantastic hydrator (4). HA can be isolated from sources like Rooster combs and through bacterial fermentation and it has proven to have beneficial cosmetic and therapeutic properties (5). As the skin ages, HA in the epidermis depletes leading to a decrease in skin moisture, thus HA in the skin can be increased through topical application or injected gel fillers. HA mostly works in the epidermal and dermal layers of the skin and once applied, it acts as a humectant, drawing moisture from the surroundings to hydrate the skin. Studies show that skin hydration, elasticity and presence of wrinkles are all improved from a prolonged use of HA in comparison to placebo controls by ~96%, 55% and ~40%, respectively (6). The size of HA molecules affects its absorption, with smaller molecules being able to travel deeper in the skin, but, smaller molecules do not hold the same level of water as bigger molecules, thus hydration is negatively impacted (7). Skincare companies attempt to navigate through this issue by formulating topical applications with a mixture of HA molecular weights.
2. Vitamin C: The Skin Brightener
Scientifically known as ascorbic acid, vitamin C is an essential dietary requirement due to the body’s inability to produce it. The vitamin’s properties are known to be important for many functions in the body due to its antioxidant activity. Exposure to UV radiation increases the number of free radicals in the part of the body that has been exposed, which in turn leads to oxidative stress which can damage DNA and even cause cell death in certain conditions. Antioxidants such as vitamin C are able to stabilise these free radicals to prevent excessive oxidative stress in cells. Normally, if there is a high concentration of vitamin C in the diet, the content in the epidermal layer of skin is also high. However, the level can decrease with prolonged oxidative stress. It has been reported that topical application of vitamin C increases levels in the skin leading to the promotion of collagen formation (through increased gene expression), hyperpigmentation fading (by inhibiting excessive melanin synthesis) and the alleviation of oxidative stress (by stabilising free radicals). Vitamin C is a water soluble molecule so it is actually very difficult to penetrate it through the skin barrier which is made up of a hydrophobic (‘water-hating’) membrane layer on the surface. Only when it’s in present in its acidic form is it able to be absorbed by the skin (8).
3. Retinol: The Skin Rejuvenator
Retinol is a specific compound that belongs to a group called the retinoids which are part of the larger vitamin A group (1). Essentially, retinol is a type of retinoid and retinol/retinoids are vitamin A derivatives. There has been a substantial effort into retinoid research since the early 20th century, but they only began being used to treat skin conditions just over 40 years ago (1). Retinol is one of the weaker forms of retinoids as other types may need to be prescribed instead of bought over the counter, due to their high potency (). When retinol is applied to the skin, it is readily absorbed as it is fat-soluble, and then it is converted to retinaldehyde followed by retinoic acid (the active form of retinol) and begins to work on the network of molecules in the dermis (2). Mainly, retinol acts to decrease and prevent the effects of natural aging and aging caused by exposure to UV radiation (sun and artificial sources). It does this by increasing the thickness of the epidermis and boosting the number of cells in the layer as well as increasing collagen production, thus smoothing out wrinkles and reverting other issues such as hyperpigmentation and lack of elasticity. Studies conducted on the effect of retinol on aged sun-protected skin, found that the topical application of 0.4% retinol for 7 days, clearly showed signs of anti-aging with epidermal thickness being two times thicker and cell numbers being 12 times higher compared to not using retinol (2). Retinoids have been known to increase the skin’s photosensitivity (extreme sensitivity to UV rays), as one of the side effects, at the beginning of treatment, therefore it is suggested to build up a tolerance to the product and wear an appropriate sunscreen to avoid further skin damage (1).
5. Sunscreen: The Skin Protector
Sunscreen is one of the most recommended skin care products there is but in my opinion it’s also one of the most disregarded steps in people’s routine. Natural light is provided by the sun, thus if it is light outside, the sun is emitting UV rays which overtime become harmful to our skin as mentioned above (9). There are three types of UV radiation, UVA, UVB and UVC but as UVC is completely absorbed by the ozone layer (10), the the two that are most important harmful to our skin are UVA and UVB. UVA and UVB exposure have slightly different effects but both contribute highly to sunburn, photoaging and inflammation (9). There are two main types of sunscreen, physical (block UV rays through reflection and scattering) and chemical (absorb high energy UV rays). The number attributed to sun protection factor (SPF), confers the amount of protection the product gives against UVB radiation, i.e SPF 30 will give 30 times more protection against UVB rays than the amount that is required to damage the skin so, the higher the number, the higher the protection (9). Protection against UVA in the EU is assigned with stars (up to 5) and again the higher the number of stars the better. Also, if UVA is circled on a sunscreen product it has met the EU standard (11). Scientific literature suggests that daily use of sunscreen, from a younger age, decreases the likelihood of developing squamous cell carcinoma by 40% and melanoma by 50% (9,12). Of course those with less melanin in their skins are more likely to experience sunburn, however, this is not the only effect of sunlight and it is highly recommended that all skin types should incorporate sunscreen in their daily regimen (13).
My skin transformation: May 2020 - September 2020.
I have been using all of the mentioned ingredients in combination for the past 4 months (retinol only for 1 month) and I cannot emphasise how much my skin has changed. I’ve had so many lovely comments about my skin and I honestly feel so much better without makeup on. Be on the look out for my skincare routine coming to my Instagram page very soon. As with most things, what works for lots of people may not work for you so make sure to do your thorough research, be open to trying new things and committed to sticking to a long-term routine. Skin care products are not miracle products, be aware of marketing scams and know that 'better skin' comes from more than applying products to your face. If you are too nervous about what to buy or don’t know where to begin, remember that you can always pay someone (a certified professional of course) to tell you.
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Until next time,
You can view my references for this blog post below.