Bath soaps, pH and skin… What do they have in common?

Heloooo everybody!

I`m very happy to come back to my posts! Let`s start with a simple question. Do you remember what does pH mean?

In simply words means "potential of Hydrogen". How much hydrogen could be present in a water soluble substances. Water in solution it`s found as H+ and OH- ions. If you have more H+ than OH- your solution could be acid. Otherwise, when you have more OH- than H+ your solution could be alkaline. When the amount of H + and OH- is equal we called this substance as neutral.  

And how is it important to our skin? Let`s figure out...  

SOAPS

Soap is made from a type of reaction called saponification. In other words, is a reaction from an animal fat (neutral) which splits into a fatty acid reacting with alkali carbonates (base), forming a salt that we call soap.

So… The most of soaps are … alkaline.

Alright, so far so good, but now I ask, what about the skin? What is the skin`s pH? Could you guess?

SKIN

One of the function of the skin is protect our body and promotes the wound healing. However, all this hard work is reliant under an appropriate pH and thickness or health of the stratum corneum cells, or better saying died cells.

The point is, the most of cleansers soaps increases skin surface pH and when it happens the died cells antibacterial capacity and barrier function is compromised. And, as consequence, you can see not only the increase of bacterial colonisation, but also the swelling of the stratum corneum which could affect its barrier function through the loss of natural humectants or the natural moisturing factor that holds water in the skin. This effect disrupts the skin`s barrier function, leading to dry, rough, red, scaly skin.  

Beside that, the surfactant in both soap and non-soap skin cleansers, they also damage cell structure and disrupt the waterproofing function of sebum leading to dryness.

And what about the infant skin?

Infant skin is clearly more sensitive than adults in terms of composition, structures, function and its susceptibility to infections. It is also has indispensable functions for their developments. It acts as a protective barrier, helps thermoregulation, exchanges gases, maintains hydration, and contributes to innates immunity. And guess what??? Its mildly acidic pH provides additional protection against pathogens.

This slightly acid pH it`s an important factor in protection against microorganisms, considering that their skin continues to develop for up 12 months after birth.

The whole of the bath

It keeps the skin free of irritant such as saliva, nasal secretions, urine, feces and fecal enzymes, dust and microorganisms.

The concern is soaps and water pHs. The repeated use of cleaning agents can alter the skin surface pH in the long term. Traditional soaps have an alkaline pH, which can destroy the skin lipid layer and elevate skin pH, causing dryness and irritation.

Ok, how could we balance it? How could I help my skin? 

Have your heard about “syndets”?

It`s a term derived from “synthetic detergent” formulated from synthetic surfactants which have good detergent effect, with neutral or slightly acid pH, and cause less irritation. Taking a bath with this type of soap is better than take a bath with only water and the combination of water and regular soaps.

So the next time that you will look for a great bath soap for your skin you may have to look for syndets. They are mostly called as “cleasing bars” or dermatological bars. They also use the term soap free or soap without soaps.

But pay attention, small part of population could get some irritation from syndets. In this case, it`s recommended that you use a traditional soap.

Let us know if you have more question!

Cheers!

References:

Duncan, C N, et al. The effect of an acidic cleanser versus soap on the skin pH and micro-flora of adult patients: A non-randomised two group crossover study in an intensive care unit. 

Giusti M.D., et al. Skin Barrier, Hydratation, and pH of the Skin of Infant Under 2 years of Age.