Natural aging, the scanning showed, caused a significant increase in the overall size of cells known as basal keratinocytes the most common cells in the outermost layer of skin as well as in the sizes of their nuclei. However, other types of skin cells, known as granular cells, did not show a similar pattern. Thus, says Sun, the relative changes in the two types of cells can serve as an index for scoring natural or "intrinsic" skin aging the aging of skin caused by programmed developmental or genetic factors.
"No one has ever seen through a person's skin to determine his or her age from their skin," says Sun. "Our finding serves as a potential index for skin age."
A skin age index would provide a standardized, quantitative scale that could be used rate the true "age" of skin, from young (less age-related damage) to old (more age-related damage). The scale could give doctors another tool to monitor the overall health of skinby investigating whether the skin of certain individuals or populations ages faster or slower than average, tracking the aging of an individual's skin over time, or testing how effective anti-aging treatments are at slowing the rate of skin aging.
Intrinsic, or chronological, aging is different from extrinsic aging, which is caused primarily by sun exposure. "There are a lot of extrinsic factors that can accelerate the aging process, such as smoking, ultraviolet light, and stress," says Sun. The researchers found that the extent of extrinsic skin aging in their study subjects varied depending on occupation, personal habits, and skin type, but because the researchers loo
|Contact: Angela Stark|
Optical Society of America