As our skin ages, it dramatically changes in structure and chemistry. A newborn has acidic skin (low pH), and as we mature past 40 years the pH of our skin changes, becoming alkaline. Adults who have spent a lot of time in outdoor activities have exposed their skin to the sun’s harmful ultraviolet irradiation, resulting in premature aged or damaged skin.
Skin as a living tissue is a reflection of our physiological maturation process. The primary physiologic influence on skin maturity is reduced blood circulation which results in: lower oxygen and nutrients delivery to skin cells, slowing rate of skin cell replacement and, consequently, thinner skin.
The dermis is the deepest skin layer where synthesis of elastin and collagen protein occurs. These tissue proteins are responsible for the elasticity and strength of the skin. Low blood circulation suppresses protein synthesis, slows the turnover rate of skin cells and increases the breakdown rate of the skin. The evidence of this is that facial expression lines deepen and skin begins to sag.
Skin cells migrate their way to the surface over time. The slower cellular turnover rate results in a longer time period for cells reach the surface. Surface skin cells accumulate becoming dull, devitalized and dead. This results in a rough skin texture.
The skin’s natural oil barrier blocks air pollutants, chemicals, microbial pathogens, and other contaminates from penetrating the skin as well as maintains skin hydration. Slowing the turnover rate of skin cells lowers oil synthesis and levels of skin cell hydration.