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How does my skin anatomy change as I get older?

As we age, our skin becomes more delicate, dry and wrinkled. See more healthy aging pictures.
George Doyle/Stockbyte/Thinkstock

Aging skin is a fact of life. At some point in each of our lives, our smooth and supple exteriors become dry, wrinkled and saggy. That is, assuming we live long enough for that to happen. And although much of aging is biologically inevitable, there are some things you can do to protect yourself from the ravages of time. The key is to avoid things that can hasten the aging process, which we will discuss in a moment. First, let's review a few basics of how skin works.

Understanding how skin works requires an understanding of its structure. Human skin is made up of three layers: the epidermis, the dermis, and a subcutaneous layer. The epidermis is what you see in the mirror. It actually has many layers itself, including a rather tough outermost portion that is constantly shaking off dead skin cells. The epidermis also has melanin, a dark pigment formed by cells called melanocytes. The more you have, the darker your skin. Your skin also responds to sunlight by producing more melanin, which gives you a tan. Melanin can also form freckles, which are simply clusters of melanin. The next layer down is the dermis, which is thicker than the epidermis and has a lot of important components, including sweat glands, blood vessels, nerves and fat. The dermis also has a certain amount of elastin and collagen fibers, which give skin its elasticity. The third and deepest layer is called the subcutaneous layer, which is mostly comprised of fat. The primary responsibility of the subcutaneous layer is keeping you warm and holding all your internal stuff in place.

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Skin is an impressive organ on a number of levels, but perhaps the most remarkable is its ability to regenerate. New skin cells are constantly forming and working their way to the top layer of the epidermis, a process that takes about two to three weeks. When new skin cells arrive on the surface, they push out the older skin cells. In children and younger adults, that amounts to a loss of about 40,000 skin cells per minute [source: KidsHealth]. So while it may look like your skin isn't doing anything, it is actually quite busy.

Now that you have an understanding of how skin works, let's talk about how skin changes as we age.

 

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If there is such thing as a fountain of youth, it surely contains a fix for lost skin elasticity. Along with gray hair and a penchant for the good old days, loss of elasticity in skin is a telltale sign of advanced age. It is mainly caused by a loss of collagen and elastin, which in turn leads to wrinkles [source: Lee]. Skin sags over time, too. This is due in part to loss of elasticity, but also to the natural pull of gravity on the skin over the course of a lifetime. As we get older, the epidermis loses lipids (fatty substances) that keep skin moisturized, further contributing to the wrinkle problem [source: American Academy of Dermatology]. Skin becomes thinner as we age - almost transparent in some cases - and loses a lot of the underlying fat layer that keeps young skin smooth and supple. Older people also experience a loss of oil and sweat glands over time, which contributes to dry skin and makes it harder for them to cool off on a hot day [source: American Academy of Dermatology].

Skin's complexion and texture can change over time, too. Probably the most dreaded sign of aging skin is the appearance of age spots, also called liver spots, which are flat areas of dark pigmentation that often appear on the face, chest, hands, arms and shoulders. In other words, those areas most exposed to the sun. They are caused by the production of excess melanin in the skin, a direct result of exposure to ultraviolet (UV) radiation [source: Mayo Clinic].

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Another way in which skin changes as we age is in its ability to renew itself. Skin regenerates very fast in children, but the rate at which it renews gradually slows with age. Very old people's skin still regenerates, but it does so quite slowly. For this reason, older people experience a slower rate of healing when their skin is injured or infected. In fact, it may take an older adult's skin two to three times longer to heal than a younger adult's skin would [source: American Academy of Dermatology]. However, age isn't the only biological factor that determines one's risk of skin changes over time. Ethnicity may also play a role. For example, premature aging due to sun damage is less pronounced in people with darker skin [source: American Academy of Dermatology]. Also, there are a number of factors in the external environment that can cause premature aging -- keep reading to learn more.

There are many external factors that can affect your skin, but two stand out as the most profound: sun exposure and smoking.

Sunlight emits three types of radiation: UVA, UVB and UVC rays. The UVC rays are the most dangerous, but our planet's ozone layer does a good job of blocking them. We Earthlings do need to worry about UVA and UVB, both of which play a role in premature aging and skin cancer. To prevent these conditions, be sure to use a sunscreen with a sun protection factor (SPF) of 15 or higher that offers protection from both UVA and UVB rays [source: Skin Cancer Foundation]. And keep in mind that the SPF of a sunscreen does not refer to an amount of sun protection. Rather, it's an indication of how long after applying the sunscreen it will take to burn your skin. For example, using an SPF of 15, it will take 15 times longer for the sun to burn your skin than if no sunscreen were applied. Ultimately, it's just best to minimize your exposure to sunlight. Seek shade during the hottest part of each day, wear protective clothing and hats whenever possible, and use sunscreen daily. And keep in mind that older skin is more vulnerable to the effects of sun than younger skin, so an SPF of at least 30 should be used.

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Smoking accelerates the aging process and causes skin to wrinkle prematurely [source: Mayo Clinic]. And the effects are not limited to the face -- smoking is associated with skin damage all over the body. The main cause is nicotine in tobacco, which restricts blood flow to the skin, causing it to be oxygen starved and more prone to pruning. But smoking increases the risk of wrinkles in other ways as well, such as through the effects of chronic heat exposure to the face and the repeated flexing of certain facial muscles used to inhale and exhale smoke. The result is often a discolored and pinched effect, also known as "smoker's face." So if you want to keep your skin healthy for as long as possible, don't smoke.

In addition to avoiding sun and smoke, there are a number of other practical lifestyle modifications you can make to keep your skin in top form, most of which are firmly rooted in common sense. For example, you should protect your skin from extreme heat and cold, avoid using harsh soaps and detergents, moisturize regularly, and keep alcohol consumption to a minimum. It's also important to minimize stress, get optimal sleep on a regular basis, and maintain a healthy weight. In other words, take good care of your whole body and, chances are, you will be rewarded with healthy skin for life.

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Sources

  • "Age spots (liver spots)." Mayo Clinic (accessed May 26, 2010)http://www.mayoclinic.com/health/age-spots/DS00912
  • "Darker Side of Tanning" American Academy of Dermatology (accessed May 26, 2010) http://www.aad.org/public/publications/pamphlets/sun_darker.html
  • "Human Skin" Discovery Kids (accessed May 26, 2010) http://yucky.discovery.com/flash/body/pg000146.html
  • Lee, JY et al. "Loss of elastic fibers causes skin wrinkles in sun damaged human skin." Journal of Dermatological Science, 2005, 50(2) 99-107 (accessed May 26, 2010) http://www.jdsjournal.com/article/S0923-1811 (07)00408-2/abstract
  • "Mature Skin" American Academy of Dermatology (accessed May 26, 2010) http://www.aad.org/media/background/factsheets/fact_mature.html
  • "Skin Care and Aging" National Institute on Aging, National Institute of Health (accessed May 26, 2010)http://www.nia.nih.gov/HealthInformation/Publications/skin.htm
  • "Smoking: Does It Cause Wrinkles?" Mayo Clinic (accessed May 26, 2010) http://www.mayoclinic.com/health/smoking/AN00644
  • "The Sun and Your Skin" American Academy of Dermatology (accessed May 26, 2010) http://www.aad.org/public/publications/pamphlets/sun_sun.html
  • "UV Information" Skin Cancer Foundation (accessed May 26, 2010) http://www.skincancer.org/understanding-uva-and-uvb.html
  • "Your Skin" KidsHealth (accessed May 26, 2010)http://kidshealth.org/kid/htbw/skin.html

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