Skin keeps the world out

Science-based skincare tips

Mapie Rosa Labelle
November 6, 2019 - 12:10

Skin is the most exposed part of our body. Our largest organ is extremely complex, being made up of three major layers, more than five types of cells as well as glands and sensory receptors. But what is skin for and how can we care for it?

 

 

Skin is our ultimate shield against the outside world. It protects us from all the pathogens, microbes, infections and sun rays in the atmosphere, while preserving the stable physical and chemical conditions of our internal organs, known as internal homeostasis. Perhaps we give skin too little credit, because the question I’m asked the most as an over-40 beauty blogger is not “how can I protect my skin in order to preserve its complex and useful functions?” but “how do I fight wrinkles?” Yet the two tasks are one and the same, and here’s my solution.

 

 

Wrinkles appear when different ageing processes hit the three layers of the skin: the external stratum corneum is affected by dehydration, the inner basal layer suffers from reduction of stem cell proliferation, and the deeper dermis loses its collagen and elastin. It goes without saying that solving only one of these problems won’t help, and a proper fight against wrinkles should take into consideration all three causes.

 

 

Mapie Rosa Labelle, author of this article

 

 

The loss of water from the skin is prevented by the external layer of squamous cells, called the epidermis. These cells (keratinocytes) are connected to each other through junctions that have the dual role of keeping water in and pathogens out. However, these cells are not intended to stay there forever: they are lost through exfoliation and replaced by new cells coming from the inner layers. As we age, the replacement of exfoliated keratinocytes with new ones becomes less efficient. This layer gets thinner over time, exposing the skin to water loss. The process can be slowed down in two steps: firstly, by rehydrating the skin and secondly, by accelerating the replacement of lost keratinocytes.

 

 

Eating a balanced diet of plenty of fruit and vegetables helps to keep skin hydrated and supplementing that with a well-designed skincare routine can work miracles.

 

 

Hyaluronic acid (HA) is one of the most effective molecules against dehydration used in cosmetics. This huge molecule acts like a sponge, keeping water in its structural holes. Using creams containing HA helps skin to stay hydrated, but given its size, HA will not enter the skin unless it’s fragmented. That’s why it’s wise to use daily skincare products with a low molecular weight HA, like the Pure Hyaluronic Acid gel from Cecina-based natural cosmetics producer Dr. Taffi Cosmetica (16.50 euro).

 

 

 

A second important ingredient in our quest for healthy skin is plant-based stem cell extract. Thinning of the external layer of skin takes place because of an imbalance between natural exfoliation and the production of new cells. Stem cells (cells that have not lost their potential to produce new cells through proliferation) produce keratinocytes in the basal layer of epidermis. Newly produced cells have to migrate towards the outside layers while differentiating to become mature keratinocytes, a process that takes about a month. With age, it takes longer, causing the external layer to thin and become dehydrated. One way to counter this natural development is to feed stem cells with factors that boost their proliferation, like growth factors. Two of them, EGF (epidermal growth factor) and IGF (insulin growth factor) are normally produced by stem cells, and once secreted they bind to receptors on the stem cell membrane, stimulating their proliferation. Similarly, incorporating stem cell extracts in our skincare products will speed up the production of keratinocytes from our skin’s stem cells, increasing the thickness of the external skin layer. Try the day cream with apple stem-cell extracts produced in-house by Farmacia Münstermann (25 euro, piazza Carlo Goldoni 2R, Florence), whose centuries-old recipes continue to be effective today.

 

 

Our third “miracle” product is Vitamin C, and here’s why. The epidermal layer lies above a deeper layer, called the dermis, which consists of connective tissue filled with extracellular matrix proteins like collagen and elastin. These two substances are known to be our skin’s scaffolding and their reduction causes wrinkles to form, just like a floor that collapses without supporting pillars. These molecules decrease with age, due to reduced production and increased degradation by specific enzymes. Vitamin C naturally boosts collagen production, so stock up in your diet and in your skincare. Look for products that have a high concentration of Vitamin C such as Kiehl’s Powerful-Strength Line-Reducing Concentrate (62 euro, via del Corso 53/55/57, Florence), which brightens the skin while reducing wrinkles over time.

 

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