Our skin is made up of three layers: the outermost layer is called the epidermis, the second layer is dermis, which contains connective tissue, blood vessels, nerve endings, hair roots and sweat glands, and finally the subcutaneous fat layer containing larger blood vessels and nerves.
The top layer of the epidermis helps contain moisture within the skin, and is normally made up of about 15% water. When the moisture content drops the skin starts to look dry and flaky and it eventually starts cracking.
The epidermis contains water soluble mixture of amino acids and salts that help skin cells hold moisture. These are known as the “natural moisturizing factor”, which limits natural water loss by regulating water flow from the deeper dermis layer of the skin.
Being water soluble, these “natural moisturizing factors’ washed out easily by strong soaps or detergents, or when our skin is exposed to solvents. Also, both the Natural Moisturizing Factor and sebum production decrease with age. Hence, the application of moisturizers is needed to prevent these water-retaining substances (natural moisturizing factors).
Moisturizers add water back to the skin. When skin becomes dry, surface cells shed too fast and come off in clumps of white flakes, repeated use of moisturizer increases the skin’s water content and helps to normalize cell turnover.
There are two key kinds of moisturizers: humectants and occlusives. Humectants attract water from the depths of the dermis or the surrounding atmosphere to help conserve water in the skin. Occlusives create an oily film on the skin’s surface to seal in moisture and prevent it from evaporating into the atmosphere.
Using a moisturizer at least twice a day is an effective way to have soft, hydrated, healthy skin.