How does the structure of my skin change as I age?

Aging skin is an inevitable part of life. Eventually, our once smooth and youthful skin becomes dry, wrinkled, and saggy—assuming we live long enough for this to occur. While much of the aging process is biologically unavoidable, there are steps we can take to slow it down. The key is to steer clear of factors that speed up aging, which we’ll explore in a moment. First, let’s review some essential facts about how skin functions.

To understand how skin works, it’s crucial to know its structure. Human skin consists of three layers: the epidermis, the dermis, and the subcutaneous layer. The epidermis is the outermost layer, the one you see when you look in the mirror. It contains several sub-layers, including a tough outer layer that sheds dead skin cells. This layer also contains melanin, a pigment produced by melanocytes that gives skin its color. The more melanin you have, the darker your skin. When exposed to sunlight, your skin produces more melanin, resulting in a tan. Melanin can also form freckles, which are clusters of the pigment. Beneath the epidermis lies the dermis, which is thicker and contains important structures like sweat glands, blood vessels, nerves, and fat. The dermis also contains elastin and collagen fibers, which provide the skin with elasticity. The deepest layer is the subcutaneous layer, mostly made up of fat. This layer helps keep you warm and holds everything in place.

The skin is a fascinating organ, particularly for its remarkable regenerative ability. New skin cells are continuously generated and work their way up to the top layer of the epidermis, a process that typically takes two to three weeks. As new cells reach the surface, they push out the older ones. In children and younger adults, this process results in the loss of about 40,000 skin cells every minute [source: KidsHealth]. So, while it may seem like your skin isn't doing much, it's actually quite active.

Now that you have a basic understanding of how skin functions, let's explore how it changes as we age.

How Skin Changes as We Age

If there were a fountain of youth, it would likely have a remedy for the loss of skin elasticity. Alongside graying hair and nostalgia for the past, diminished skin elasticity is a prominent sign of aging. This loss is primarily due to the decline in collagen and elastin, which results in wrinkles [source: Lee]. Over time, skin also begins to sag. This sagging is partly due to the loss of elasticity, but gravity’s effect on the skin over a lifetime plays a major role. As we age, the epidermis loses lipids (fatty substances) that help keep skin hydrated, exacerbating the wrinkle issue [source: American Academy of Dermatology]. The skin becomes thinner with age, sometimes appearing almost transparent, and loses much of the fat layer that gives youthful skin its smooth and supple texture. Older adults also experience a reduction in oil and sweat glands, leading to drier skin and difficulty cooling off on hot days [source: American Academy of Dermatology].

The texture and appearance of skin can change as well. One of the most dreaded signs of aging skin is the appearance of age spots, also known as liver spots. These are flat patches of dark pigmentation, typically appearing on the face, chest, hands, arms, and shoulders—areas that are frequently exposed to the sun. Age spots are caused by an overproduction of melanin in the skin, a direct result of exposure to ultraviolet (UV) radiation [source: Mayo Clinic].

As we age, our skin's ability to regenerate slows down. In children, skin renews quickly, but as we get older, the process becomes much slower. While elderly individuals still experience skin regeneration, it occurs at a much slower pace. This explains why older adults take longer to heal when their skin is injured or infected—sometimes it can take two to three times as long compared to younger adults [source: American Academy of Dermatology]. However, age isn’t the only factor influencing skin changes. Ethnicity can play a role as well. For instance, people with darker skin tend to show fewer signs of premature aging from sun exposure [source: American Academy of Dermatology]. External environmental factors also contribute to early skin aging—keep reading to learn more about those.

How External Factors Affect Your Skin as You Age

There are several external factors that can affect the health and appearance of your skin, but two of the most significant are sun exposure and smoking.

Sunlight contains three types of radiation: UVA, UVB, and UVC rays. UVC rays are the most harmful, but fortunately, the ozone layer protects us from them. The primary concern for us is UVA and UVB rays, both of which contribute to premature aging and skin cancer. To protect yourself, use a sunscreen with an SPF of 15 or higher that offers protection from both UVA and UVB rays [source: Skin Cancer Foundation]. Remember, the SPF number doesn’t indicate how much protection a sunscreen provides, but rather how much longer it will take for your skin to burn compared to not using sunscreen. For example, with an SPF 15 sunscreen, it would take 15 times longer for the sun to burn your skin than if no sunscreen were applied. The best strategy is to limit sun exposure altogether—seek shade during the peak sunlight hours, wear protective clothing and hats, and apply sunscreen daily. Since older skin is more sensitive to the sun, use a sunscreen with at least an SPF of 30 for optimal protection.

Smoking accelerates the aging process, leading to premature wrinkles on the skin [source: Mayo Clinic]. And the damage isn't just limited to your face—smoking harms skin across the entire body. The main culprit is nicotine, which constricts blood flow to the skin, depriving it of oxygen and making it more susceptible to damage. Smoking also increases the risk of wrinkles in other ways, such as through the chronic heat exposure to the face and the repetitive use of facial muscles involved in inhaling and exhaling smoke. The result often appears as a pinched, discolored look known as "smoker's face." To keep your skin looking its best, avoid smoking altogether.

Along with steering clear of sun exposure and smoking, there are various simple lifestyle changes you can make to maintain healthy skin, most of which are rooted in common sense. For instance, protect your skin from extreme temperatures, avoid harsh soaps and detergents, moisturize regularly, and limit alcohol intake. Managing stress, getting enough sleep, and maintaining a healthy weight are also essential. Essentially, taking care of your body as a whole will likely lead to healthier skin over time.