When you think of or look at skin, what is the first thing that comes to mind? Does it have a healthy glow? Is it a certain color? Is it wrinkled or blotchy or just plain dull? Skin is the first thing you notice when you look at yourself and others, and it is also your body’s first line of defense from UV exposure, weather, germs and other insults.
As skin care professionals, you look at skin more closely and, more importantly, you try to understand why skin looks a certain way. The skin is the body’s largest organ, and is part of both the integumentary system and the excretory system, where it is responsible for removing waste from the body in the form of perspiration, or sweat. Skin is a canvas, painted by each individual’s genetics, lifestyle choices and product use, requiring skin care professionals to understand skin function and ingredient mechanism of action in order to provide each client with the best treatment plan for their skin, regardless of Fitzpatrick type or condition.
One brick at a time
The skin is comprised of two main sections, separated by the stratum basale, or basal layer. The dermis, which is the lower portion of the skin, lies just above the adipose layer; the epidermis, the outermost layer, is protected by the stratum corneum (SC). Each section of the skin works together and, if just one component is not functioning properly, then the entire structure can become compromised. In short, outer, visible skin is a reflection of everything that is happening underneath.
The dermis is made up of three major types of cells: fibroblasts, macrophages and adipocytes. It is also composed of what is known as the extracellular matrix (ECM), which contains collagen for strength; elastin for elasticity; and glycosaminoglycans (GAG) that support and maintain collagen, elastin and turgidity within the spaces between the cells. GAG also encourage the ability of these matrix fibers to hold on to moisture, keeping them soluble. Because the ECM is the support system for the epidermis, it is crucial to keep it healthy and functioning properly. If this structure becomes weakened and unable to provide the necessary support required to maintain the epidermis, then outward signs of aging begin to appear, such as wrinkles, sagging, enlarged pores, loss of elasticity and, ultimately, a loss of the youthful appearance associated with firm and healthy skin.
Don’t let me fall
The epidermis provides the human body with a barrier from external insults and is reliant upon the dermis for support and hydration. The SC, the outermost layer of the epidermis, is comprised of lipids, such as ceramides, cholesterol and free fatty acids that maintain hydration and protect the new cells rising from the basal layer. As mentioned previously, the ECM within the dermis is the scaffolding, or the support structure, that gives the epidermis its bounce and elasticity. When explaining this to clients, a good comparison is to a mattress and box springs. If the box springs (ECM) weaken, then the mattress (epidermis) sags. Another important function of the dermis is to provide the epidermis with hydration. Because limited amounts of water are able to penetrate through the epidermis from the outside, it must be able to attract and hold the moisture that is provided by the dermis from the inside. Because people lose several ounces of water through the epidermis on a daily basis, known as transepidermal water loss (TEWL), a delicate balance must be maintained between the dermis and the epidermis. Should TEWL become excessive, the result is impaired barrier function, meaning the epidermis is no longer providing the barrier protection that is vital to overall skin health. Impaired barrier function presents as irritated, inflamed and flaky skin, often giving a rough, red and dry appearance. Imagine the outward appearance of skin with an impaired barrier and without ECM support, and you can see the importance of these two major components and how they directly affect skin health.
Build me up
Fortunately, through current skin health science and technology, many topical products are available that are formulated with combinations of ingredients proven to reinforce and stimulate the production of dermal proteins, prevent their breakdown, provide hydration to the epidermis, and protect it from UV and cellular damage. Many of these ingredients perform more than one function, which benefits both the skin care professional and the client.
Antioxidants. Antioxidants are necessary because they neutralize free radicals, which set off a chain of events within the skin that damage skin cells and lead to visible aging. The epidermis contains the highest concentration of antioxidants, some of which are produced on their own, and some that are absorbed through food intake and the application of topical products. Vitamins A and C function both as antioxidants, and provide the extra bonus of stimulating matrix proteins and suppressing pigment production. Some of the most potent antioxidants available currently include soy isoflavones, glutathione, silybin from milk thistle and caffeine.
Matrix metalloproteinase inhibitors (MMPi). These help to inhibit the overproduction of enzymes within the dermis that are responsible for the breakdown and recycling of old elastin, collagen and GAG, such as hyaluronic acid. Elastase, collagenase and hyaluronidase are responsible for breaking down used elastin, collagen and hyaluronic acid, respectively. The natural aging process, overexposure to UV and oxidative stress caused by free radicals cause an increase in the production of MMP enzymes, which then begin to attack healthy matrix proteins. MMPi suppress these enzymes, preventing the breakdown of these crucial proteins. Vitamin C, resveratrol from red grapes and EGCG from green tea are not only powerful MMPi ingredients, but they also function as antioxidants.
Peptides. These compounds consist of two or more amino acids. Depending upon their size and structure, different peptides perform specific functions within the skin. Acetyl hexapeptide-8 helps to reduce wrinkle formation by minimizing the frequency of muscle contractions between the eyebrows (glabella) and around the eyes (periorbital). Palmitoyl pentapeptide-4 stimulates the fibroblasts within the skin to increase types I and IV collagen fibronectin.
Humectants. Humectants are crucial to proper barrier function and the outward appearance of the skin. These ingredients attract water to the outer epidermis. Hyaluronic acid can hold 1,000 times its molecular weight in water, and sodium PCA is able to attract 250 times its weight. Other powerful humectant ingredients are honey, panthenol, urea and glycerin. It is important, however, to understand that using humectants by themselves is not enough to maintain healthy barrier function. It is equally important to incorporate the use of occlusive agents to hold the newly acquired moisture within the skin and keep it from evaporating. Humectants can be thought of as magnets that attract the water while occlusives are the locks that hold them within the skin.
Occlusives. These must be chosen carefully. Many ingredients can be effective occlusives, but create a thick, greasy or heavy feel. Petrolatum is one such ingredient. Look for silicones such as dimethicone, cyclomethicone and cyclopentasiloxane, which are occlusive agents that create a light, almost powdery finish. Plant-derived oils, such as borage, evening primrose, jojoba and rosehip seed, are not only compatible with human skin, but many also contain essential fatty acids (EFA) and provide anti-inflammatory benefits. Niacinamide is unique in that it actually stimulates the production of the skin’s natural lipids while also providing anti-inflammatory and antioxidant benefits.
Broad-spectrum UV protection. This is no longer a choice in maintaining overall skin health—it is a must. Every one of your clients should be educated on the importance of UV protection, regardless of age, skin type or condition. Many formulations are available now that are cosmetically elegant and provide complete broad-spectrum protection. You can also find UV-protecting products that are enhanced with antioxidants, melanogenesis inhibitors, matrix-building ingredients, and humectants and occlusives. With all of the options available today in SPF products, there is no excuse for clients to keep sunscreen out of their daily regimen.
Healthy skin on all levels
Everyone, regardless of age, color or skin type, wants to see healthy, glowing skin looking back at them in the mirror. As skin care professionals, you want to provide that for your clients. By taking a deeper look and understanding skin function from the inside out, you will be able to help your clients attain the skin health goals they desire at every level.
Jennifer Wild, DO, is board-certified in family practice and since 2004, she has pursued an active interest in esthetics and skin care, including dermal injections, lasers, professional skin care treatments and products. Her vast knowledge in both the medical and esthetic industries has allowed her to excel within the industry as an advanced educator for PCA Skin.