Love the Way You Age
This article is reprinted from the Fall 2017 edition of MindScope,an entirely student-produced science magazine. Writer Ally Jarvis ’20 is a junior majoring in biology. Her goal is to become a physician assistant and eventually specialize in surgery.
Some of the very first signs of human aging can be seen on the surface of our skin. Aging is an inevitable process and unfortunately, the most visible signs of our increasing age are in plain sight. Until the Fountain of Youth is discovered, simple steps can be taken every day to reduce signs of aging and ensure healthy and supple skin. The epidermis, or the top layer of skin, reflects not only age, but health as well. Before we can dive into the concepts of skin aging, prevention, and care, it is important to understand some of the fundamental concepts of skin.
Largest Organ of the Human Body
The epidermis is the largest and fastest growing organ of the human body (1). It is involved in regulatory processes such as temperature control and fluid and electrolyte balance (2). In addition, it contains nerve receptors, giving us the power of touch and the perception of pain and pressure (2). However, perhaps the most important (and obvious) role of our skin is to protect our insides from the environment.
While the skin is made up of many complex layers, the basic and generalized physiology of skin includes the epidermis, the dermis, and the subcutaneous layer. The epidermis has the power to self-renew itself by a process known as differentiation in which a single epidermal basal cell progresses from the lower basal layer, undergoes keratinization, becomes a keratinocyte, and ends at the outermost layer of the skin as a corneocyte (3). Layers of the epidermis work collectively to constantly repair, protect, and maintain composition. These extremely advanced processes, however, can only be conducted with communication to the dermal layer underneath, which contains fibroblast cells, collagen, and elastin (3).
Factors of Change
Based on this overview of skin, it seems like we have a built in skin care system. If the layers of skin are continuously working together to generate new skin cells and protect older ones, why do we age? Why does our skin become visibly dull, thin, and wrinkled? Changes in the skin are related to a myriad of factors. Some of the biggest contributors include genetic makeup, environmental factors, and lifestyle habits (2). Above all things, the single greatest factor of skin change is sun exposure. According to an article by American esthetician Lydia Sarfati, almost 90 percent of the visible skin changes commonly attributed to aging are caused by the sun and can be seen as early as in one’s 20s (8).
Inside the Skin Aging Factory
Depending upon age, health, and environmental influences, it takes the average skin cell 28 days to surface and be sloughed off (3). In our late 20s, this natural process of differentiation begins to decline. During this time, the amounts of collagen and elastin begin to decline, resulting in a gradual decrease in firmness and elasticity. Specifically speaking, the dermis and epidermis begin producing one percent less collagen each year (6). Yikes.
As the aging process continues, the epidermis thins, melanocytes decrease, and the remain melanocytes increase in size. As a result, the skin appears thinner, paler, and almost translucent (2). In sun-exposed areas, large pigmented spots will become noticeable; including age spots and liver spots. The connective tissue also changes, reducing in amount thus reducing the skin’s strength and elasticity. This change is known as elastosis and can be more noticeable in sun-exposed areas (2).
How the Sun Affects Skin
For every summer that ends in a great tan, your skin is quietly plotting against you. Every moment we spend in the sun adds up like credit card payments. While in the moment it seems like a good idea it’s usually never worth the bill that comes later. When ultraviolet rays penetrate the epidermis, they generate free radicals that harm the cellular material (8). Free radicals include atoms, ions, or molecules that contain an unpaired electron. This makes them unstable and highly reactive. When oxidation occurs, free radicals steal electrons from other molecules that make up body fats, proteins, cell membranes, and even DNA (free radicals are also generated by air pollution and cigarette smoke) (5). According to Lydia Sarfati, increased accumulation of UV radiation with age causes damage to the the dermal matrix, leaving it disorganized (8). UV radiation causes collagen to decrease and the skin loses its elasticity and becomes thin. This is one of the main causes of wrinkles. Keep in mind that natural aging already causes a decrease in collagen. Therefore, UV radiation simply speeds this process up.
When UV rays strike the skin, they can either be reflected, scattered, or absorbed. UV and visible light absorption occurs because of melanin granules in the epidermal cells. The main role of melanin is to protect the skin from damaging effects of sunlight. When exposed to the sun, especially high UVA and UVB radiation, melanin production from melanocytes is stimulated, which results in a pigmentation increase. UVA differentiates from UVB because it can penetrate deep into the dermis and plays a direct role in skin aging and wrinkling (4). Although equally as harmful, UVB usually burns the superficial layers of skin, playing a key role in the development of skin cancer (4). The hyperproliferation of melanocytes, in which melanin is produced at abnormally high rates, is what causes age spots on the epidermis (8). This increase of melanin is called melanogenesis and is also induced by DNA damage from UVB radiation (8).
Protecting and Prepping Your Skin for Change
Depending on age and current damage, everyone will have a slightly different recommended skin care routine. However, keeping the epidermis looking smooth and radiant as long as possible means taking care of it no matter how old you are. Suzan Obagi, assistant professor of dermatology at the University of Pittsburgh and director of the Cosmetic Surgery and Skin Care Center offers her advice in a short article for the Scientific American.
In general, everyone should be applying a sunscreen of at least SPF 35 every day. Obagi recommends using one that contains zinc or titanium (7). Once a patient reaches the age of 25, Obagi believes that you should be using Retin-A. This product is a vitamin A derivative and is generically called tretinoin (7). The purpose of this cream is anti-aging. Lastly, Obagi states that if tretinoin is not enough, enzyme peels and laser surgery can help rebuild collagen and improve skin’s overall appearance (7).
When dealing with medical and health issues, it is always recommended to see a licensed physician, in this case a dermatologist. However, by spending a few minutes on the internet, you can easily learn more about skin care and skin health. When picking out a skin regimen, make sure you include a sunscreen that is at least 35 SPF. Read reviews and do research so you know what to expect when trying new skin products. We all have different skin, and it is important to choose products that work best for you. Keep in mind that aging is a natural process and the consistency of proper skin care, both professionally and at home, is the secret to maintaining healthy, youthful skin.
This article is reprinted from the Fall 2017 edition of MindScope, an entirely student-produced science magazine. Writer Ally Jarvis ’20 is a junior majoring in biology. Her goal is to become a physician assistant and eventually specialize in surgery. She originally wanted to specialize in dermatology and is still considering it. Ally graduated from “a very small high school with weak science and math departments.” She credits “the amazing STEM faculty [at Simmons] for helping me recognize my passion for biology and for making me believe in myself.”