The skin is a complex structure of cells.
The skin is the body`s largest organ covering about 1.5-2 square meters, accounting for roughly 12-15€ of total body weight. The skin protects the rest of the body from UV radiation, microbes, and dehydration. The skin can perform all the functions necessary for a perfect life.
The skin consists of three layers:
- The epidermis (the outer layer) has many layers – the palms and heels, for example, have both five sublayers.
- The dermis (the “real” skin).
- The subcutaneous layer (the bottom or fatty layer).
The four to five layers of the epidermis illustrate the life cycle of keratinocytes and keratin-producing cells. As a new, viable cell moves upwards from the lower layer of the upper skin, it becomes stiffer and drier, eventually ready to fall off the body. We usually associate the word “skin” with these lifeless, external cells. But in reality, skin cells’ main vitality and functions are beneath this dead top layer. The reason why cells become hard in the outermost layer of the epidermis is directly related to the protective functions of our body. A wall of dead cells protects the living tissues beneath it. Living cells contain 80% of water, but there is only 1% of water in the air. Living cells would shrink and perish if such dry air came into direct contact with them.
The epidermis has a four-week life cycle, during which the outer layer is entirely replaced. This process slows down as you get older. Keep in mind that your skin condition can’t improve overnight.
The dermis (or “real” skin) is the skin’s largest layer. It is strong and elastic and accommodates the body’s essential systems – vascular, lymphatic, glandular, nerve endings, and hair. The dermis has fewer cells than the epidermis, and it is wrapped by a strong fibre called collagen. Collagen plays a significant role in the healing of wounds.
The dermis also contains tiny blood vessels that supply nutrients to the epidermis and nerves, allowing the skin to function as a sensory organ. The dermis has the wisdom to feel touch, pain, heat, and cold.
The deepest layer of the skin is the subcutaneous fat layer, which is made up primarily of collagen and fat cells. Most fat is stored here. Fat metabolism, synthesis, and decomposition are all connected with subcutaneous tissue.
Also, the microbiota of our skin, i.e. the microbes living primarily in the upper layers of the skin, cannot be overlooked. The microbiota of healthy skin produces a variety of antimicrobials and enzymes that strengthen the skin’s defences against harmful microorganisms and allow the immune system to keep us healthy and strong. Chronic diseases such as psoriasis, atopic dermatitis, acne, and rosacea are associated with changes in the microbiota.
How can we use this knowledge in skin care?
It seems like an impossible task at first. However, LUMI has two simple principles – balance is the key, and less is more. We have made hundreds of clients happy and guided them back to health.
Roughly speaking, overconsumption causes half of today’s skin problems, while unhealthy lifestyles cause the other half. We often receive a genetic “package” and imbalances with our bodies. Even babies can have skin problems. In this blog post, we are focusing on external skincare rather than internal factors.
We are all victims of advertising, and it often seems that the more products and procedures we use, the better the result must be. Unfortunately, we often see the opposite – the skin is over-cared for and often severely damaged, making a recovery a long and challenging journey.
LUMI is here to simplify the process – we have the experiences and feedback from our customers, and the basics gathered over the years to help you.
What does our skin need?
Our skin needs a solid and healthy protective barrier and sufficient hydration.
Let’s talk about the protective barrier first. The most outer layer of the epidermis is called the stratum corneum. It is a massive barrier with keratinized cells, making it difficult for skin care products to absorb deeper into the skin. In addition to the stratum corneum, the active ingredients of the products are also blocked by another barrier – the basement membrane between the epidermis and the dermis.
Still, the body absorbs the substances. However, this process varies from person to person. And it is influenced by a variety of factors like skin heat, gender (men’s skin is often tighter), skin type and condition, hydration level, and individual physical-biochemical properties. But also product quality, quantity, and length of contact (leave-on vs wash-off).
Our skins can react differently to the same cosmetic products. Massage oil is an excellent example of this. You may find that a much larger amount of oil is absorbed into the skin because the body is warm from the massage, and the oil is used in larger quantities than if you were to use it under normal conditions. Let’s compare this absorption with, for example, face oil, where only a few drops are enough. It shows that “by the book” rules only sometimes apply in skin care.
The skin’s protective barrier regulates whether and how the body absorbs cosmetics.
Healthy skin has a considerably stronger protective barrier than damaged skin. Keep it in mind while choosing skin care products and deciding how to guide the beneficial active components deep into the skin. When the stratum corneum is thick, its cells are scaled and unevenly patterned, and the skin’s natural barrier is lower, allowing it to absorb substances more quickly. Applying cosmetics to dehydrated and flaky skin can cause a burning sensation. Excessively wet skin can also contribute to irritation since the barrier is softer, and the product penetrates faster through the layers of the skin.
We recommend applying skin care products to damp or wet skin. Especially during the winter when the air is dryer than usual and when using a product that contains water-binding active ingredients like hyaluronic acid. Applying hyaluronic acid to dry skin can actually “suck out” the moisture, which is why some people complain about the drying effect of hyaluronic acid serum. The product is suitable for hydrating the skin, but proper application is critical. Test it on your skin first. With extremely sensitive skin, starting with a slower absorption rate (apply to dry skin) may be necessary to give it time to adjust and recover.
The secret weapon of skin care – high-quality vegetable oils preventing dehydration
Occlusive agents prevent transepidermal water loss. Vegetable oils, fats, squalane, and beeswax are natural occlusive agents. They are a must-have in your skincare routine because they help to control water evaporation from the skin! The oil “traps” the water and softens the skin. Because mature skin produces less oil as it ages, it’s critical to use high-quality facial oil to maintain a protective barrier. In addition to aging processes, the skin’s lipid layer is also damaged by soaps, alcohol, perfumes, and harsh weather conditions. The lipids relevant to the stratum corneum in vegetable oils are also crucial – fatty acids keep your skin’s protective layer healthy and strong.
Lipophilic elements dissolve very easily in the stratum corneum of the skin’s surface layer, but further absorption of the oil is blocked because the fluid between the epidermis cells is hydrophilic. According to a study comparing the absorption of mineral, jojoba, almond, avocado, and soybean oils into the skin, none penetrated past the first 2-3 layers of corneocytes. Only almond and soybean oils made it to the third layer; all other oils stayed on the skin’s surface or only made it to the first two levels. It is also essential to know the composition of the oil that penetrates your skin. The authors of this study highlighted the importance of using vegetable oils instead of mineral oils. Vegetable oils are similar to the body’s lipids. Therefore, they are absorbed into the skin by an enzymatic breakdown. Vegetable oils are rich in antioxidant vitamins A, C, and E. But mineral oil is a very simple molecule with only two atoms: carbon and hydrogen. Instead of synthetic mineral oil, ensure your skin care product contains high-quality, unprocessed vegetable oils!
Water and water-based compounds – vegetable oil’s partners in crime
It is difficult to overestimate the importance of hydrating the skin. Most of the human body is water. It is no surprise that our skin needs water, not just vegetable oils. We frequently hear that using high-quality skin oils still keeps the skin dry. Some think the product is to blame – it doesn’t deliver on its promises. In reality, it is vital to use all products correctly, keeping our personal needs and skin condition in mind.
A strong barrier can keep moisture in, but more hydration is needed because of our lifestyle and sometimes poor skin care. The most well-known moisture-producing substance used for this is hyaluronic acid, which can bind its weight many times in water. Because this water is mainly extracted from the skin and rarely from the environment, it is essential to apply moisture-binding substances on wet skin!
Now, let’s talk about the molecular weight of hydrating compounds. Mixtures with different molecular weights can penetrate different skin layers. The larger ones remain in the skin’s top layer, which is also very important. We don’t need only low molecular weight substances; we also need compounds with various molecular weights!
Now that we know that our skin includes both water and fatty acids, we can see why combining cream and oils, rather than just a facial oil, is effective in skin care.
Read more about it: Smoothie magic – the perfect mix for your skin.
Sources: Imbi Smidt, University of Tartu, Research Fellow in Medical Microbiology, “Advanced Skin Science”, Herb & Hedgerow Ltd. 2015