In order to understand how to take care and improve skin health it is essential to understand the structure and function of the skin.
Once you learn about its delicately balanced structures and processes it makes complete sense to treat the skin in a particular way.
Hundreds of thousands of years of evolution has created an incredible, multifaceted organ. Mostly known for acting as a physical protective barrier, it also uses its microbiome as a bacterial “alarm system” communicating potential threats via chemical signals to the immunological cells. All these different “lines of defence” work together to create a resilient barrier that protects our internal selves from the external world around us.
Although the skin is only about a millimetre thick there is an awful lot packed in there!
I will go through all the skin defence systems and how skin care, diet and lifestyle affect each.
What we call the ‘first line of skin defence’ which is made up of a mixture of bacteria, fungi, mites, viruses, sweat and sebum; collectively known as THE MICROBIOME. When you read it in black and white it sounds pretty gross doesn’t it (!?) but all these things are integral to keeping a strong and resilient skin. Sebum is the perfect nutrient source for the commensal microbes and our sweat and by-products of microbial metabolism create the acid mantle or pH layer which is the optimal acidic environment (pH 4.5-5.5) for microbes to work at their best.
Most microbes are beneficial and only a small percentage cause problems for the skin when conditions allow for them to get out of control.
It is important to understand that it isn’t as simple as good” and “bad” bacteria but instead it is usually an IMBALANCE of particular strains that create problems on the skin.
Many factors influence the microbiome;
The second line of skin defence are the keratinocytes – hardened skin cells that create a roof-like protective layer called the stratum corneum. These keratinocytes were once plump cells that have made their way up from the basal layer, through the granular layer and undergone the critical transition of keratinisation, all strongly connected together by protein links called corneodesmosomes. This layer is designed primarily to provide physical protection but it also communicates with all the other layers of the skin; continually sending and receiving messages in a ‘feedback loop’ to optimise the huge array of chemical reactions and processes happening in order to maintain optimal function.
The third line of skin defence is the lipid bilayers which are like the mortar between the brick like corneocytes. This is made up of ceramides, fatty acids and cholesterol that sit in layers to provide the water retention and lubricating properties.