Alpha Hydroxy Acids (AHAs)
The use of Alpha Hydroxy Acid products for anti-aging skin care has been around for quite some time, and for good reason...they work. Cleopatra herself realized the beneficial effects that the alpha hydroxy acid present in donkey’s milk had on her skin. Alpha hydroxy acid products may contain one or more of a number of acids included in this group. Glycolic acid, lactic acid, and citric acid tend to be the most common. AHAs can be found in a variety of products including cleansers, toners, masks, moisturizers, and exfoliating scrubs. So what are alpha hydroxy acids and what do they do that have allowed them to withstand the test of time?
As explained in the Exfoliation page of this site, skin renews itself from the bottom up with new skin cells being formed in the bottom layer of the epidermis and eventually migrating upward until they reach the surface where they die and eventually fall off. As we age, the time between cell death and the sloughing process increases. As a result, dead skin cells build up on the skin surface causing the complexion to appear grey, dull, lined, and dry. AHAs help to exfoliate these dead skin cells more rapidly by disintegrating the “glue” that binds them to the surface of the skin. As a result, newer, more healthy skin cells are exposed.. Removal of the dead cells also enables skin renewing products to penetrate more easily and deeper into the skin.
Of the many alpha hydroxy acid products available, most seem to contain either glycolic acid, lactic acid, or citric acid, as these are the most popular. Glycolic acid comes from sugar cane and provides a multitude of skin rejuvenating benefits due to its small molecular size. Since it penetrates the skin easily, it is effective in exfoliating dead skin cells, reducing skin oils on the surface of the skin, removing skin impurities such as blackheads, smoothing out fine lines, moisturizing, and bleaching skin discolorations. It is also believed that glycolic acid can stimulate collagen production within the lower layer of the skin, the dermis.
Lactic acid is derived from sour milk. In addition to dead skin cell removal, it is also known for its ability to hold water within the skin thereby maintaining its hydration. Well hydrated skin appears plumper and less lined.
Citric acids contain vitamin C which is an antioxidant and serves to reduce free radical damage to the skin. Vitamin C is also known for its ability to stimulate the production of collagen.
Alpha hydroxy acid products come in a variety of concentrations. The FDA allows over-the-counter formulations to contain up to 10% AHAs. Anything less than 8% has been shown to be ineffective. At concentrations between 8% and 10%, effects are not seen immediately but will become apparent with continued use. AHA concentrations up to 30% are used by salons for “mini peels”. The procedure is performed every eight to ten weeks and tends to cause mild irritation that usually resolves within 48 hours. Mini peels are effective for reducing the look of fine lines, evening skin tone, and correcting hyperpigmentation. High concentration AHA peels must be performed by a dermatologist. This procedure is recommended for deep wrinkles and acne scarring. It is likely to cause skin irritation that persists for up to one month and should be performed no more than once per year.
When using alpha hydroxy acid products, you must diligently protect your skin from the harmful effects of the sun as these products make your skin much more vulnerable to sun damage. If you have sensitive skin, consult your dermatologist because the use of AHAs may be too harsh for your skin type. Also, it is not necessary that every product in your anti-aging skin care regimen contains AHAs. In fact, doing so might lead to excessive skin irritation.
