A Chemistry Lesson for Healthy Skin

Confused by ads that toss about the phrase "pH balanced,” making a chemistry degree seem mandatory for undertaking a skincare routine? In a world where science melds with advertising, medical reality is often blurred. Yet healthy skin chemistry is anything but hype or creative marketing. Leaping straight out of a science lesson, this measure of product acidity or alkalinity can be critical for maintaining healthy skin.

Posted on | Audrey Kunin, MD | Comments ()

Confused by ads that toss about the phrase "pH balanced,” making a chemistry degree seem mandatory for undertaking a skincare routine? In a world where science melds with advertising, medical reality is often blurred. Yet healthy skin chemistry is anything but hype or creative marketing. Leaping straight out of a science lesson, this measure of product acidity or alkalinity can be critical for maintaining healthy skin.

Each and every year, we are faced with the same winter dry-skin dilemma. And while using heavy cream-based moisturizers, utilizing a humidifier, and reducing exposure to harsh winter weather are all helpful, conquering this concern requires establishing an acidic environment for the skin.

Here’s what is going on. The skin is naturally acidic with a normal pH of 4.5-5.5. And women have been proven to have more acidic skin than our male counterparts. 

Chemistry Lesson

So what is pH anyway? Simplistically, it's nothing more than a measuring system for comparing the strength of acids and bases. An abbreviation for "potential of hydrogen,” chemists long ago established a scale from 1 to 14 to assess these properties. Water, the elixir of life, is neutral; it is neither acidic nor alkaline. It was assigned the midway point on the scale: 7. Any number below 7 is categorized as an acid; those above, a base. (Note: the terms base, basic and alkaline all refer to the same thing.) The further the pH shifts from 7 in either direction, the stronger (and potentially irritating) the solution. So a compound with a pH of 3 is more acidic than one at 5; a base at 8 is less potentially irritating than one at 10.

The Acid Mantle

An imperceptible thin viscous fluid, the acid mantle, maintains and protects the overall health of skin and hair. Secretions formed by sebaceous and eccrine sweat glands comprise the acid mantle. Sebum (the oily substance produced by the sebaceous glands) and sweat, (the salty, watery mix produced by the eccrine glands) blend and are further acidified by secretions from normal flora of the skin (bacteria known as Staphylococcus epidermis). The normal acid mantle for both skin and hair ranges between 4.5 and 5.5. Sunlight, diet, excessive sweating and the application of skin or hair products can all lead to disruptions in the acid mantle.

pH and Skin Care

The epidermis is protected by an external layer of tightly knit cells arranged like shingles on a roof. Any disruption to the acid mantle, elevating overall skin pH, interferes with this protective barrier, wrenching cells away from each other and results in dehydration, roughness, irritation and noticeable flaking. Skin is left defenseless and susceptible to further environmental damage.

As cells pull apart, minute breaks become exposed, leaving skin more vulnerable to bacterial invasion. Under normal circumstances, bacteria not only have a difficult time penetrating through the shield-like structure of the skin and the acid mantle also creates a hostile environment for bacteria which prefer an alkaline environment to flourish. A rise in pH plays mayhem with our natural infection prevention, further increasing the risk of infection. Once the pH exceeds 6.5, bacterial invasion increases dramatically, a loss of normal skin integrity results and a variety of skin disorders such as eczema, psoriasis and irritant contact dermatitis flare.

Achieving pHabulous Looking Skin

Washing the skin with moderately or highly alkaline soap or detergents (cleansers that foam are typically high in detergents) is one of the most common mistakes made that strips away the acid mantle. Shampoo running down the face is another common source of detergent exposure.

Toners are typically stripping, pH inappropriate and lacking in hydrators. If you’re a toner enthusiast, look for one that is healthy for your skin and make the switch.

Use of a cleansing agent that contains a buffered glycolic acid or other alpha hydroxy acid (AHA) is a great way to keep epidermal cells lying tightly upon each other and skin glowing.

As for hydration, if you already have parched, irritated skin, applying an acidic AHA product is not an option until you have soothed and settled with a "bland" moisturizing cream. After you've dealt with the healing phase, go into preventative mode and apply an "active" moisturizer, one chockfull of AHAs to help prevent dehydration, remove scale and maintain the acid mantle.

Take a moment and reevaluate your daily skin care regimen. After all, achieving healthier skin is as simple as understanding and following proper skin chemistry.

Blog written by Audrey Kunin, MD
Dr. Audrey Kunin is a board-certified dermatologist, author, clinician, educator and President of DERMAdoctor, Inc. Dr. Kunin...