One of the most important roles of our skin is to protect our ‘insides’ from the external environment, acting both as a barrier and a filter between ‘outside’ and ‘inside’. In addition, the skin is involved in regulating our body’s temperature, like when we have a fever or we’re physically working hard, we tend to sweat, which is the body’s way to attempt to lower the temperature.
Another important role of our skin is to protect us from harmful substances entering our body, and in eliminating toxins. This takes workload off our Liver and Kidneys to filter out by-products from our body’s metabolism. The skin also breathes!
Hormones, Sweat glands and pH
The pores of our skin are made up of a combination of oil and sweat glands (sebaceous and sudoriferous glands) helping to keep our skin healthy and elastic. An excessive sebum secretion is often associated with oily skin and acne. This is particularly common in adolescents as the increased levels of sex hormones stimulate sebum production and secretion. When in balance, the combined excretion of oil and sweat from the skin’s pores has a pH of about 5.5.
The Acid Mantle, Age and the importance of the skin’s pH
This slightly acidic layer, also referred to as the “Acid Mantle”, is our body’s first defence mechanism against SkinCell PRO bacteria invading it and is not a favourable environment bacterial growth to occur. This defence layer develops at puberty, which is why children are more susceptible to disease, viruses and fungal infections such are ringworm. The pH of children’s skin is closer to neutral (pH 7).
At puberty, however, we start to produce more hair on our bodies. Hair follicles have an associated sebaceous gland or glands which become active as hair growth increases, causing changes in the skin’s pH. The hormones that control sweat also become active and the whole surface of a teenager’s skin is totally different to that of a young child. This is our body’s way to increase our defence system.
The pH of normal, healthy human skin is somewhere between 4.5 and 6. However, this varies with age. Typically, newborns have a pH closer to neutral (pH 7) that quickly turns acidic in order to protect young children’s skin.
In the late teens to early 20’s, our Acid Mantle is well developed and provides good protection against potentially harmful, external environmental factors. Our skin usually looks healthy, heals quickly when injured and seems to take care of itself.
With increasing age however, the skin’s pH becomes more and more neutral, and thus more susceptible to bacterial growth. This reduced acidity kills fewer bacteria than before, leaving the skin susceptible to bacterial growth and infections. The skin weakens as a result and begins developing problems with increasing age. (Interestingly, the pH value rises beyond 6 when a person actually suffers from a skin problem or skin disease.)
The aging process of the skin causes biochemical changes in collagen and elastin, the connective tissues underlying the skin, which give the skin its firmness (collagen) and elasticity (elastin). The rates of loss of skin firmness and elasticity differs from individual to individual, depending on their genetic makeup, general health, over exposure to the sun, skin care regime, or lack there of, and other factors.
As the skin becomes less elastic, it also becomes drier; the underlying fatty tissue begins to disappear resulting in the skin beginning to sag. Our skin is less supple, and wrinkles begin to form. At this stage, our skin is more easily injured, heals more slowly and tends to dry out more quickly.
The role of pH in Acne
As outlined above, the skin’s pH is important and maintaining a slightly acidic pH of around 5.5 is critical.
The skin’s pH value is one of the major contributors to acne and other skin problems. Propionibacterium acnes is a bacteria that normally lives on the skin and is a normal bacteria found in all persons regardless of the presence or absence of acne.
However, in individuals prone to acne, the number of P. acnes is greatly increased. It has been found that the growth of this bacteria is very much dependent on the pH value of the skin and its growth is at its minimum at the normal skin pH of 5.5. A slight shift towards the alkaline pH would provide a better environment in which it can thrive.