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How does skin age?

James M.. Wilmott
Dermatology

There is no simple answer for the reasons that skin ages the way it does.  There are many complicating factors which are involved.  Skin aging is pre-programmed due to each person's genetic makeup which slowly causes a deterioration in cellular metabolism.  However, the signs of skin aging can be accelerated by the effects of the environment.  Radiation from over-exposure to the sun, the application of harsh chemicals, microbial infections, stress, reactions to medications, medical conditions such as diabetes, and even the food that is consumed can compromise the genetic and structural integrity of  the skin.  There are several theories regarding the causes of skin aging:

  • High energy free radicals are formed that damage healthy DNA,  proteins, cell membranes and other biochemicals.
  • Sugars can cause structural proteins like collagen and elastin to crosslink and lose their integrity reducing firmness and creating wrinkles.
  • DNA mutates and produces poor bio-molecules resulting in skin that does not reproduce correctly.  This causes it to become dull, wrinkled and its outer barrier damaged.
  • Inflammation causes the breakdown of collagen, elastin, hyaluronic acid and other key components that produce wrinkles and can cause pigmentation disorders.
  • The immune system is compromised leaving it vulnerable to the effect of micro-organisms and other environmental allergens.
  • The composition of the endocrine(hormone) system are programmed to change over time which impacts the firmness, elasticity and suppleness of the skin.
  • Changes to the surrounding environment where the DNA is located in the nucleus and mitochondria (energy factories) of the cell causes different genes to be expressed thereby altering cellular metabolism.

Aging is often synonymous with slowing down, and that’s nowhere more true than in the skin’s deep layers. Collagen and elastin fibers are renewed more gradually, which invites sagging. Production of glycosaminoglycans tapers off, meaning skin gets superdry. Skin heals more slowly and there are also fewer immune system Langerhans cells, so skin is more vulnerable to infections.

From The Mind-Beauty Connection: 9 Days to Less Stress, Gorgeous Skin, and a Whole New You by Amy Wechsler.

As we age, so does our skin. The aging skin is influenced by both intrinsic and extrinsic factors. 

Intrinsic aging is the result of the skin cells' activity slowing down due to genetics. Keratinocytes, the structural cells in the skin, don't divide as quickly as they did when we were younger. Dead cells build up on the surface of the skin, which makes the skin appear dull and lusterless. Collagen and elastin make up the support network of the skin, and they also are not made as much as they were when the skin was younger. With lower amounts and damaged collagen and elastin, the skin is not as elastic as it once was and does not spring back into its original shape when stretched. This translates to sagging. Finally, sugars that are like the mortar around the skin cell bricks deplete with age. So the skin loses its bounce.

Extrinsic aging has to do with environmental damage. Ultraviolet light, smoking, and pollution all are associated with skin aging. UV light causes a buildup of oxygen free radicals that damage skin cells and collagen. In addition, it leads to irregular pigmentation and prominence of sweat glands.

While you cannot prevent intrinsic aging, you certainly can fight against extrinsic aging by preventing your exposure to UV light with sunscreen!

 

 

Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)
As we get older, our skin becomes thinner and dryer, so keeping skin moisturized is particularly important. It is also beneficial to avoid any products that contain ingredients that can cause skin irritation and damage, such as harsh cleansers.


Dr. Ellen Marmur, MD
Dermatology
Webster's dictionary defines senescence as "the state or process of being or becoming old." Basically our own state of senescence, or decay, involves making less of everything and slowing production down. The factory workers in the skin are heading into retirement, and their work is getting sluggish. Keratinocytes aren't turning over as fast as before, so the complexion looks dull since dead cells aren't shedding. Some studies claim that by the age of forty, the twenty-eight day skin turnover cycle slows to forty days! There aren't as many fibroblasts replenishing themselves, and the ones that are working aren't producing collagen as plentifully.
Collagen, elastin, and chains of sugar molecules called glycosaminoglycans (GAGs), which hold water like sponges, make up the extracellular matrix in the dermis. This matrix plumps and cushions the skin like packing foam, but UV exposure and toxic oxygen radicals dissolve it every single day. The skin sags because there's less of this supportive matrix and less fat, and much of what's left is no longer firmly anchored by collagen and elastin. The epidermis becomes thinner, and there are fewer lipids and ceramides (the mortar of the stratum corneum), so the skin's barrier is drier and compromised. (The loss of estrogen at menopause exacerbates this.) Intrinsic factors (genetics, gravity, and senescence) and extrinsic factors (sun exposure, smoking, pollution, and environmental influences) intensify the negative effects of the aging process.
Simple Skin Beauty: Every Woman's Guide to a Lifetime of Healthy, Gorgeous Skin

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.