Alpha Hydroxy Acid (AHA)
Alpha Hydroxy Acid (AHA) — the family name for a group of naturally occurring acids often referred to as “fruit acids.” AHAs are used in cosmetics as moisturizers, emollients, and exfoliants. They are also employed to treat such conditions as photodamage, hyperpigmentation, eczema, and ichthyosis. Their activity and associated benefits are dependent on the type of AHA used, the concentration employed, and the pH of the formula. The benefits attributed to AHAs include a reduction of fine lines and superficial wrinkles, a lightening of surface pigmentation, and softer, suppler skin with improved hydration. These noted benefits are a result of AHA activity to normalize the stratum corneum by reducing its thickness through exfoliation, and the creation of a more compact structure; increased skin hydration because of the natural moisturizing properties; an ability to activate hyaluronic acid, which in turn will retain a greater amount of moisture in the skin; and an increase in dermal thickness because of increased hydration and a normalization of skin functions. There are seven key AHAs found in various plants and fruits: glycolic acid found in sugar cane juice; lactic acid from sour milk and tomato juice; malic acid found in apples; mandelic acid found in almonds, tartaric acid from grapes and wine; and citric acid found in lemons, pineapples, oranges, and other fruits; and pyruvic acid. an organic acid that probably occurs in all living cells. Of all the AHAs, glycolic and lactic acid are the most popular for use in skin care.