Figure A. Layers of skin. Note the outer (or epidermal) layer
Figure B. Epidermal (outer) layer of skin
The skin is composed of several layers, each with its own anatomy and function (Figure A). The outer or epidermal layer also is divided into several sub-layers, each with distinct stucture and cell form (Figure B). (Reference 1)
Skin cells are continually developing and maturing as they move upward toward the outermost layer, the stratum corneum. It is this layer where skin cells are positioned both anatomically and physiologically to provide perhaps the body's most important defense against environmental insults such as harmful bacteria and viruses.
The stratum corneum is distinctly acidic (has a lower pH) compared to other skin layers - so much so that this skin layer (and its function) has historically been referred to as the "acid mantle" of the body.
2) Washing and Sanitizing
Washing and sanitizing can lead to a compromised stratum corneum and reduced protective capability against environmental insults. (Reference 2)
Most soaps have a high pH (9-12) which is hostile to the outer skin layer's pH of 4-6. (Keep in mind that each pH unit represents a 10-fold difference in acid level!). Repeated washing with soaps can compromise both the stratum corneum's form and function - its structure and ability to offer protection to the body. (Reference 3)
Likewise, repeated sanitizing with alcohol-based sanitizers can also compromise this barrier. Most hand sanitizers contain 70-80% alcohol and can denature cell membranes and dry the skin (Reference 4). The use of moisturizers is recommended along with sanitizing for this very reason.
In this day of frequent washing and sanitizing, the need is more pressing than ever to not only moisturize the skin, but restore the natural pH and provide valuable nutrition to the protective outer skin layer .
3) Restoring Protective Function of Skin
Most skin moisturizers are formulated to approximate neutral pH (7.0) or slightly acidic pH (6-7). (Reference 5).
Following hand washing using soaps that have a high pH (9-12), the use of a moisturizer with a significantly lower pH can facilitate the skin to more easily restore the acid mantle function, helping get the outer layer of the skin back to its natural pH of 4-6. Utterly Divine's Skin Renewal Lotion is formulated with a pH of just below that of the outer skin layer to efficiently promote restoration of proper pH in the outer skin layer.
Besides helping with skin pH, the inclusion of goat milk kefir in the Skin Renewal Lotion brings valuable nutrition such as B vitamins (especially B1 and B12) to nourish the outer skin layer. (Reference 6)
REFERENCES 1) AB Wysocki. Skin anatomy, physiology, and pathophysiology. The Nursing Clinics of North America, 1999, 34(4):777-97. 2) E Larson. Hygiene of the skin: when is clean too clean? Emerg Infect Dis 2001, 7(2):225-230. 3)SM Ali, G Yosipovitch. Skin pH: From Basic Science to Basic Skin Care. Acta Derm Venereol, 2013, 93:261-267.4) Nyamwweya, N.N.; Abuga, K.O. Alcohol-Based Hand Sanitizers – A Multidimensional Perspective. Preprints 2020, 2020090337.5) A comparison of physicochemical properties of a selection of modern moisturizers: hydrophilic index and pH. Shi VY, Tran K, Lio PA. J Drugs Derm, 2012, 11(5):633-636.6) S Oties, O Cagindi. Kefir: A Probiotic Dairy-Composition, Nutritional and Therapeutic Aspects. Pakistan J Nutr, 2003, 2(2): 54-59.