1. Getting to know your skin
Is it really that important for us to understand the science of skin, or can I skip this chapter and just jump ahead to find out what routine I should follow for my combination skin?
The answer is … this is an ESSENTIAL chapter. My aim here is to explain the different layers that make up your skin, the role of melanin, how ingredients work on these layers and outline the classic mistakes that most people make so that you can avoid them! If you don’t understand skin anatomy and physiology, you won’t know how ingredients and products actually work. If you don’t know how products and ingredients work, you will continue to fall for all the marketing gimmicks, expensive adverts or enchanting-smelling creams that are vying for your attention – and money.
I want to empower you to make the right choices by giving you the knowledge and science to truly understand your skin, pay attention to it closely and learn how it recovers and renews itself each cell cycle, depending on your age, skin type and skin concerns.
The science that follows will help you to understand your skin from the tiniest skin cell all the way up to the biggest pore that you wish you could minimise!
Being confident in your own skin is everything.
Everyone wants to get that glow – the healthy, radiant skin that makes them feel amazing every day. We all want to feel comfortable in our skin and give it the love and care it needs in order to look and feel as good as possible.
The first impression we usually have of a person is from their face. We can instantly estimate age and health and assess if someone might be stressed or if they haven’t been sleeping well.
The skin performs major functions to keep our bodies healthy, too, such as keeping bacteria out, performing thermoregulation (the body’s process for regulating your body temperature) and keeping our internal structures intact. But for the purposes of this book we will focus more on practical step-by-step information to help you understand how to care for your skin, stop wasting money and avoid irritation to your body’s largest organ!
This journey through our skin is your roadmap to understanding how different ingredients work – and where they work or have an effect in our skin – so here’s a bit of science before we start to help you get to know your skin.
The layers of the skin and why they are important
Hypodermis – this is the deepest skin layer, primarily made of fat, which is located under the dermis. This layer acts as a cushion to protect all our organs – liver, heart, kidneys as well as muscle and bones – against shocks and knocks and also aids temperature insulation. As we age, we lose fat in these areas, which causes the skin to shrink. This is why losing a lot of weight after the age of 40 years old can mean your skin is less elastic and doesn’t bounce back into place like it used to in our youth.
Dermis – above the hypodermis sits the dermis. This is the middle layer of skin, which is about 2mm thick. Visually, imagine a mesh of collagen and elastin, for strength and elasticity, forming the scaffolding of the skin. Peak collagen is at 21 years old, then after this we produce 1 per cent less collagen annually. This leads to sagging skin and fine lines from your mid to late twenties, which is why using SPF50 from a young age is important. (I will go into more details about anti-ageing skincare through the decades in chapter five.)
Now imagine this meshwork of collagen and elastin are soaked in water magnets called glycosaminoglycans (a common one that you might have heard of is hyaluronic acid). Their purpose is to bind water molecules, which keeps the dermis hydrated and plump.
Also among the collagen/elastin mesh and the water-binding glycosaminoglycans you have an immune system that responds to stimuli, leading to inflammation triggering your melanocytes (melanin-producing cells), which in turn leads to hyperpigmentation (see chapter four). This inflammatory cascade is complex and not well understood, but what we do know is we need to minimise any trigger of inflammation to minimise chances of PIH (Post-inflammatory Hyperpigmentation).
Keeping our skin calm and happy is essential for skin of colour, in order to avoid hyperpigmentation.
Blood vessels constrict and dilate to control body temperature, which is why your skin turns red or deepens in shade after exercising. The blood vessels are bringing oxygen to the dermis to regulate your temperature, as well as to bring nutrients to cells and remove carbon dioxide. However, there are no blood vessels in the epidermis.
But if there are no blood vessels in our dermis, does that mean the top layer of skin is basically dead skin cells?
The border between the epidermis and the dermis is a wavy line called the dermalepidermal junction (science is not known for its imaginative names!). This wavy dermal-epidermal junction (where the epidermis and dermis meet, also known as the basal layer) creates a large surface area where the transfer of nutrients and oxygen to the lower levels of the epidermis can take place. The upper layers of the epidermis are indeed dead. This is important to know because exfoliation for skin of colour should only remove dead skin cells through controlled chemical exfoliation (see chapter two on exfoliation, here) not aggressive physical exfoliation, which can remove live epidermal cells, which can lead to inflammation and sensitivity.
As you age, this wavy junction between the dermis and epidermis flattens, which means there is a smaller surface area for oxygen and nutrient transfer. This is one of the reasons for skin ageing.
Epidermis – this is where almost all the magic happens with cosmetic creams. The key point is that the epidermis is constantly turning over and shedding; new skin cells start at the basal layer and travel up the skin conveyor belt until they are seen on the surface. This process is called cell renewal.
The epidermis is 0.1 mm thick, on average, which is the same thickness as the pages in this book!
Skincare science...
