Alpha and Beta Hydroxy: Allies for the Skin

Although hydroxy acids have received much attention in both the scientific and media communities, these naturally-occuring acids are heralded skin enhancers that have been used for thousands of years. Even the Queen of Egypt revered the use of hydroxy acids as a method for rejuvenating her famous skin. It has been the Queen of beauty regimes bathed nightly in sour milk (a common form of a-hydroxy acid), to improve the appearance of her skin.

More and more research is showing a clear link between wrinkles, photo-aging and the use of hydroxy acids as a method to reverse or prevent the effects of sun-based aging. The following article will define alpha and beta hydroxy acids, explaining how they work, as well as their effectiveness in treating wrinkles. It will also provide a helpful look into using these acids safely, as well as some of the side effects of their use.

What are Alpha and Beta Hydroxy Acids?

Hydroxy acids are divided into two subgroups, alpha and beta. Alpha hydroxy acids (AHAs), are chemical compounds, both synthetic and natural, that are made up of a carboxylic acid that has been substituted with a hydroxy group on the adjacent carbon. In common parlance, they are are exfoliants that come natural substances such as the glycolic acid produced from sugar cane and the lactic acid produced from milk.

AHAs are in many cosmetic products. They are known to help in reducing the signs of aging, and scientifically, their effectiveness in improving the look and feel of skin has been well-documented. Some well-known hydroxy acids include: glycolic acid (from sugar cane), lactic acid (from sour milk) citric acid (from fruits), malic acid (from apples), and tartaric acid (from grape wine).

There is only one beta hydroxy acid (BHA) used in skin-care preparations, and that is called salicylic acid. This form of BHA is used in many "anti-wrinkle" creams, as well as acne treatments.

The key difference between beta and alpha hydroxy acids is their lipid (oil) solubility. While beta hydroxy acids are lipid soluble, alpha hydroxy acids are only soluble in water. In this sense, beta hydroxy acid has the ability to penetrate a skin pore that holds old oils, sebum and dead skin cells. This is particularly valuable in the cases of oily skin, acne and blackheads. Alpha hydroxy acids work to soften skin that has been sun-damaged, loosened, and thickened by aging.

How They Work to Effectively Treat Wrinkles and Other Skin Concerns

In the form of a topical compound, AHAs have the ability to penetrate into the pores of the skin, where it can act on our skin living cells. Because of the small molecular size of glycolic acid, this form of AHA is very popular in anti-aging, anti-wrinkle preparations. Alpha hydroxy, due to its small molecular structure, has the ability to deeply penetrate the skin, helping it to produce more collagen and elastin. Collagen is responsible for giving skin a thick, pliable and wrinkle-free characteristic. Elastin is responsible for the amount of “bounce-back” and elasticity in the skin, typical of a youthful epidermis.

Beta hydroxy acid act primarily as an exfoliant, causing the cells of the skin to become "unstuck.” This process sloughs off dead skin cells, creating space for re-growth of new skin. It also loosens skin plugs, improving both the size and functional capacities of skin pores.

Studies show that both alpha and beta hydroxy acids can improve the appearance of wrinkling, and uneven skin tones in photo-damaged skin within 6 months of application. Derived from the same ingredients in aspirin, beta hydroxy acid has powerful anti-inflammatory properties, reducing both swelling and redness in the skin. This acid also aids in accelerating the process in skin cell turnover and rejuvenation.

Usage Recommendations and Possible Side Effects

Alpha hydroxy acids are normally quite safe as a topical cosmetic agent for the skin, particularly when used in the recommended dosage. Occasional common side-effects include mild irritation, redness and flaking of the skin. If the concentration of the pH level is within a range of 3.5-4, and the concentration of AHA is 10% or less, there should be less chance for irritation. Chemical peels, which have a much higher concentration of acids, are usually responsible for the more harmful side-effects. This may include mild forms of redness, blistering, burning and skin discoloration, which go away within a short time period. One should also be very careful to wear sunscreen with UVA and UVB protection when dealing with both forms of alpha hydroxy acids, as both increase sun sensitivity. Symptoms may include burning, redness, burning, itching, and scarring.

The use of beta hydroxy acid has even more chances for increased sun sensitivity. Studies show that, especially in lighter-pigmented skin, a 50% increase in sensitivity may occur. Other side effects may include temporary redness, burning, itching, pain, and possibly scarring. Beta hydroxy acid works best in a concentration of 1% to 2% and at a pH of 3 to 4.