Alpha Hydroxy Acids is the family name for a group of naturally occurring acids often referred to as ‘fruit acids’ due to the fact that they are derived from fruit.
They are used in cosmetic products as moisturizers, emollients and exfoliants. They treat conditions such as photodamage (sun damage), hyperpigmentation, eczema and ichthyosis. Their activity and associated benefits is dependant on the type of AHA used, the concentration employed and the pH of the formula.
There benefits include:
- A reduction of fine lines and superficial wrinkles
- Lightening of surface pigmentation
- Softer, suppler skin texture
- Increase in healthy cell regeneration
These noted benefits are a result of the AHA activity to normalize the stratum corneum (outer skin layer) by reducing it’s thickness through exfoliation and the creation of a more compact structure; increased skin hydration due to the moisturizing properties of the AHAs; their ability to activate hyaluronic acid which, in turn, will retain a greater amount of natural skin moisture; and an increase in the dermal thickness to the increased hydration and a normalization of skin function.
There are 6 key AHAs:
- Glycolic acid (sugar cane)
- Lactic acid (sour milk and tomato juice)
- Malic acid (apples)
- Tartaric acid (grapes and wine)
- Citric acid (lemons, pineapples, oranges and other citrus fruit)
- Pyruvic acid
The exfoliating and hyperkeratinization-reducing properties of natural AHAs make them prime ingredients for acne-orientated products, for reducing actinic keratosis, and for improving the appearance of ageing skin. Also, their emollient and hydration properties help dry and aged skin.
Of all the AHAs glycolic, lactic and malic acid, and their salts, are the most popular for use in the cosmetic industry. For these to be safely incorporated into these preparations at concentrations 10-15%, with the product’s final pH not being lower than 0.
Lactic and Malic acid are 100% pure, natural acids. They are not synthetic like glycolic acid, which is supposed to be derived from sugar cane; however, because it needs to be buffered to stabilize the pH, it is assured that the acid is synthetic.
Natural AHAs are not buffered. Peeling agents only have to be buffered if they are synthetic and require the pH of the product to be stabilized. If one has a neutral pH then the product is not exfoliating to any degree. NATURAL acids are more easily absorbed and cell regeneration is enhanced with more rapid healing. Synthetic acids cause a short, sharp shock to the skin. When this occurs one may experience superficial peeling, however, there is no long-term therapeutic action. It must also be noted that synthetic acids such as glycolic acids are inexpensive to manufacture and therefore the products containing these, should also be inexpensive.
If one wishes to eliminate pigmentation or have a dramatic effect on sundamage, solar keratoses, potential cell changes and promote true rejuvenation, then natural acids in HIGH concentration with a very LOW pH are required.
AHA work on the skin as an exfoliant for as long as it is present on the skin and for this reason I is important to remember that it is vitally important to remove the product containing it from the skin before going into the sun as the UV rays will affect the ‘exposed’ skin and therefore cause pigmentation to occur.
When using an AHA preparation on your skin it is also important that your day preparation contains a SPF (Sun Protection Factor) of at least 16. You also need to take note that the SPF in the product is not purely chemical as these have an effect on your natural skin layers. A good sunscreen will always incorporate both chemical blockers as well as physical blockers.
If you are considering going for a peel in a skin care clinic, always remember that there are mild side-effects to high concentration as used in the clinics and ask your therapist to explain these to you.