Exploring the connection between skin and brain.
To understand neurocosmetics, we must first understand our skin.
Its unique composition and properties are at the heart of this white paper and help us explore the link between the skin and the brain.
Before we discuss the structure of the skin, we need to look at its functions.
The more traditional view points to protection and thermoregulation, but this list can be extended to many other things. Albert Kligman, in his book, only begins to name them: (Immunological, Endocrine, Metabolic, Psycho-social, Neuro-psycho-immunological, And so on…). This can also be simplified to two general functions:
1. it establishes barriers.
2. it filters exchanges with the outside world.
And it is this last function that we look at to understand the connection to the brain.
The skin, which is the largest organ, is also the support for the greatest number of neuroreceptors.
In fact, in one cubic centimeter, we can find up to 800,000 neurons and more than 10 meters of nerves.
This exchange can occur at multiple levels of sensory inputs from the skin surface, also described as the skin's cutaneous sensitivity.
The neural architecture of the skin allows for a very wide range of reactions, such as the communication of temperature, pain or itch, as well as one of the most fundamental sensations for human development, touch.
Some of these reactions occur at the physical level, others at the biochemical level, a sphere explored primarily by medical experts rather than the cosmetic industry.
Two-way communication, from skin to brain and from brain to skin, can help the entire cosmetic industry explore the notion that, on the one hand, mental state has a direct impact on the health and appearance of the skin and, on the other hand, it is possible to positively influence mental state by communicating with the entire neurological network through topical applications of oils, creams and serums.
NEUROCOSMETICS A VERY CONTROVERSIAL DEFINITION
Although not an official scientific term, neurocosmetics has been the subject of heated debate in recent years, with marketers and experts alike of the cosmetic industry trying to adapt it to their needs.
Attempts have been made to adopt this name to describe different types of products. One of the most common, promoted by cosmetic marketers, was the notion of cosmetics to help with well-being or affect mood.
In the same way that a nice piece of clothing or makeup can lift your mood, cosmetics can have the same effect. However, this effect comes from psychological rather than biochemical sources. And it is the latter that truly characterizes neurocosmetics, as Professor Misery described in 2000:
"We can summarize this group of products as, non-absorbed products applied to the skin, exhibiting activity on the cutaneous nervous system or in general effects on cutaneous mediators."
It is therefore the neurotransmitters present in the receptors of skin cells that are the target of true neurocosmetics.
Therefore, this field is primarily interested in exploring ingredients, both natural and synthetic, that can impact the nervous system. The range of these effects can vary, from the sensation of temperature – both cooling and warming, through inflammation and pain relief, to those that affect endorphin and cortisol levels.
As early as 1925, it was discovered that various skin conditions could be treated with a combination of psychotherapy. Inflammation, psoriasis, eczema, as well as aging can be attributed to a chemical balance related to stress (cortisol) or relaxation (endorphins or oxytocin).
A new scientific field called psycho-neuro-endocrine-immunology (PNEI) has been developed to explore the relationships between the mind and the nervous, endocrine and immune systems.
Some of the examples from the scientific community explore the effects of neuroactive ingredients on the endings of cutaneous nerve fibers, as modulators of neurotransmitter release. This can be illustrated by active ingredients that stimulate the relaxation of facial muscles, thus having wrinkle smoothing properties. They can also decrease the sensitivity of the skin to external stimuli – making it less reactive.
Neurocosmetics are usually composed of various active ingredients that interact with our nervous system and can be combined or amplify the effects of other ingredients.
Examples include calming substances such as glycyrrhetinic acid, moisturizing substances such as polysaccharides (the most popular of which is hyaluronic acid) or plant extracts that promote the penetration of active substances into the epidermis.
