Skin

One of the most common physical changes that people associate with aging is the wrinkling, pigment alteration and thinning of the skin. We now know that these changes reflect the amount of exposure to the sun (i.e., ultraviolet light) more than aging per se. Most of the "aging" of the skin is due to the effects of environment and disease.

The most common changes in the skin include:

1. a thinning of the area between the dermis and epidermis by about 20%
2. elastin and collagen decrease
3. reduction in size of cells
4. inability of skin to retain moisture

One factor in the aging of the skin are changes in two important fibrous proteins-elastin and collagen-which determine the elasticity and resiliency of the skin. The skin becomes less able to retain fluids and is more easily dry and cracked. As a result, both the thickness and elasticity of skin decrease. Therefore, sunscreens and moisturizing creams play an important part in protecting aging skin.

In addition to changes in the skin itself, the subcutaneous layers of fatty deposits dwindle with age. This gives some very old people an emaciated appearance. Using a microscope, a dermatologist can estimate a person age by examining changes in their skin structure, usually to within 5 years. This is because the dermis thins almost 20 percent with aging as the number of cells decrease.