While it may appear like a single unified system, in reality the skin is stratified into three main layers, each of which has its own specific characteristics. The bottom layer, called the dermis, is where substances like collagen, hyaluronic acid and the cells that make them reside. Above the dermis is the epidermis. This is the bulk of the skin surface. It's where the skin cell (aka keratinocyte) hangs out. The very tippy top, called the stratum corneum, is the so-called skin barrier. It's what gives the body's largest organ its resilience and protective properties. It's also responsible for helping the skin hold on to water and maintain its hydration status, critical for healthy cutaneous chemistry.
Dry skin is the end result of a poorly formed stratum corneum. Because this barrier is derived from cells that have traveled or transited upwards from the bottom of the epidermis, the more efficient their movement, the stronger and more effective the barrier.
One of the best ways to support cellular transit is to apply alpha hydroxy acids or AHAs to the skin several times a week. Lemon juice contains AHA. So does apple cider vinegar and wine; both red and white.
When the AHAs these liquids contain contacts the skin surface it encourages the sloughing off of dead skin cells, in turn triggering the transit of new cells, which will ultimately form the stratum corneum. In this way, the barrier stays healthy and strong, minimizing water loss and helping the skin maintain an appropriate level of moisture.
