…because it’s the only outfit we will wear for the rest of our life.
Did you know that true skin health starts deep inside? In fact, the condition of our skin, along with our hair and nails, gives a good indication of our internal health.
As with most health conditions, skin conditions start in the gut. How our gut processes food, assimilates nutrients and expels wastes has a direct impact on the health of our entire body, including our skin.
Our skin is our largest organ! That’s right. It’s not just a flesh bag to carry our muscles and bones in, it is an organ and has a functional role in our health and wellbeing.
Let’s have a look at the structure of our skin.
The skin is comprised of three main layers. The outer most layer is called the epidermis; this is the part of the skin we see and touch. This layer varies in thickness, depending upon the body surface it covers. For example, the skin on the soles of our feet is thicker and courser than the skin on our face. The cells that make up this layer are called keratinocytes.They layer together, like a brick wall, producing a physical barrier to protect our body from external pathogens. This outer most layer also contains melanocytes to give the skin its pigment [colour] and protect it from the sun by producing melanin. Langerhans cells [immune cells] are also a part of our skin. They provide both a physical and chemical barrier to protect our body.
The next layer down is the dermis. It is 20–30 times thicker than the epidermis and is structurally made up of collagen—a denser, more fibrous substance—and elastin which gives the skin its stretchiness. The dermis layer is what gives our skin structure, integrity and elasticity and houses hair follicles, sweat and sebaceous [oil] glands. These structures provide sweat and oil to the skin surface, creating a barrier to pathogens.
The bottom layer is known as the hypodermis. It is made up of a specialised layer of adipose [fat] and fibrous tissue. It cushions and insulates the body and stores excess energy in the form of fat.
It takes about 28 days for the skin cells to move from the base layer up to the surface layer. Once they reach the outer most layer, the bonds between the cells break apart and the skin sloughs off. Any changes made internally for skin health can take up to a month to be apparent. Routine is key here. Stick with it, be consistent and the changes will surface.
Now we know a bit about the structure of our skin, let’s have a look at how it functions.
The main function of the skin is to act as a barrier between our internal and external environments. It acts as both a physical and a chemical barrier to prevent microbes, chemicals, allergens, toxins and carcinogens from entering our body. This function is supported by the immune cells located in our skin tissue.
Our skin does this by dilating or constricting the blood vessels near the surface of the skin and this controls the transfer of heat out of our body. As previously mentioned, the fatty layer of the skin provides insulation against the cold. Our other temperature control mechanism is through evaporative cooling via our sweat.
Ultraviolet (UV) protection
This occurs through the production of melanin, produced by the melanocytes. Melanin is a dark pigment that gives skin the multitude of colours we see. The darker the skin tone, the more melanin present. Upon exposure to UV light, the melanocytes upregulate their melanin production. This melanin travels up to the keratinocytes where it absorbs the UV light, protecting the basal layers underneath from UV damage.
Vitamin D production
This is a fat-soluble nutrient essential for our health and wellbeing. Vitamin D is a little different to others in that it doesn’t come from our diet but rather from exposure to sunlight. We make a cholesterol-based substance called 7-dehydrocholesterol in the sebaceous glands of the skin (these same glands produce sebum and can become infected in acne). Exposure to sunlight, specifically to UVB rays, converts this substance into vitamin D over a 2–3 day period.
The skin has a large nerve supply which gives us the sensation of touch. The skin is a direct interface with our external environment and is constantly feeding back sensory information to our brain.
When the integrity of the skin is compromised, through injury or a wound, it has a cascade of events to help the wound close and heal as quickly as possible to protect the organism—you.
Ok, so what does all of this have to do with our gut you might be wondering…
Both our gut and skin are highly innervated and have an extensive vascular supply [nerves and blood are what we are talking about here]. The skin and digestive systems are where the outside meets the inside and provide a physical and immune barrier to prevent our internal structures from exposure to pathogens. You might be aware of the gut microbiome—a population of microbes inhabiting the digestive tract, essential to homeostasis. Well, our skin has its own microbiome.
Research has established a bio-directional communication between the gut and the skin known as the ‘skin–gut axis’. So, we could think of our digestive tract as the internal skin system. In fact, it is lined with cells that are similar in structure to that of our external skin cells and is host to a multi-functional population of microbes. As such, these two organ systems are essential to the structure, function and health of the organism—again, you!
As naturopaths, we commonly see clients with skin issues who also have some level of gut dysfunction, and we wouldn’t treat one without the other. Acne, dermatitis and psoriasis are three common conditions that are very much related to the gut and manifest in the skin.
Now you know a bit about the structure and function of our skin, what can we do to help ensure healthy skin through all phases of our life?
One of the biggest influences we can have on the health of our skin [and our gut] is our diet. Just like everything else in the body, our skin needs nutrients to do all the amazing things it does. Eating a diet rich in nutrient-dense foods helps to feed and nourish the microbes in the gut and on the skin. Because the lining of the gut and the skin are made up of living cells, they need nutrients to carry out their many functions. Having a healthy, optimal-functioning gut that can digest, absorb, synthesise and assimilate nutrients is paramount to healthy, nourished, glowing skin.
Here are the top skin-loving nutrients.
Yep, our cells, including skin cells, are made of fat. To make sure they are nice and plump and juicy, ensure you have regular intake of good quality fats. Oily fish containing essential fatty acids or cold-pressed organic olive oil are loved by our entire body, including the skin.
Fat soluble nutrients
Protects the skin from UV damage and slows ageing of the skin. It also promotes healthy skin cell production, keeping the skin barrier intact, which means nice, firm, healthy skin. Through this action of enhancing skin integrity and barrier, it also prevents against infection. When the skin surface is damaged in some way (even through dryness), it makes it easier for an infection to enter.
It comes from the sun and is synthesised by our skin cells. Vitamin D ensures the healthy turnover of skin cells, promotes wound healing and maintains the barrier of the skin. It is also an essential nutrient for the immune system and fighting infections.
This provides protection from the sun, preventing sun damage to the skin, and also anti-inflammatory and wound healing properties. Being a fat-soluble nutrient, it helps to keep skin cells plump and juicy.
Protein and collagen
The protein we eat is broken down into amino acids, the building blocks of our body. The body uses the amino acids to make other proteins – collagen and keratin – which form the structure of the skin.
Working hand in hand with collagen, Vitamin C allows the protein matrix to hold its shape and is also helpful for the immune system and fighting off infections.
Water makes everything in our body work better and the skin is no exception. Our skin loves pure filtered water. Water aids in digestion, circulation, absorption of nutrients and even the excretion of wastes. While our cells might be made of fat on the outside, they have water on the inside which helps them to keep their structure and carry out all the functions they need to.
To sum it all up, our skin is a living organ in the body, made up of various types of cells with specialised functions. Both our skin and our gut have an ecosystem of microbes that have many beneficial functions in maintaining health. These microbes communicate with each other. Eating a nourishing wholefood diet helps to support the health and function of both our skin and digestive tract.
A note on skincare
Be informed about what you put on your skin. If you can’t pronounce the ingredients, or you wouldn’t eat them, it’s probably safe to say you don’t want them on your skin either! There are heaps of luscious natural skincare products on the market or why not make your own?
If your skin needs some extra love and support or if you have acne, psoriasis or dermatitis, the issue isn’t skin deep. It is gut mediated and we need to support your gut health to support your skin. Book a consult with a naturopath to assess what is going on and the best way to support you and your skin.
Written by Amanda Lorch (BHSc)
Naturopath & Kinesiologist