by Bob Sandewicz, Chemist
Juan Ponce de Leon is best known as the man who sought the elusive “Fountain of Youth”. That the famous explorer landed in what today is Florida is deliciously ironic, given that state’s large senior citizen population. Poor Juan truthfully cannot be blamed for his pursuit of perpetual youthfulness, as humans always have tried to maintain a fresh, young appearance. Throughout the ages, various formulations, either home-made or store-bought, have been touted as helping to restore the look and feel of the skin. Roman physician Galen is credited with having created the world’s first cold cream; fashioned from beeswax, borax and water, the preparation felt cool when applied to the skin. As we “fast-forward” to 2010 and examine the skin care products sold in Sephora, Nordstrom, or your local pharmacy, it is obvious that we still have the same passion for looking younger. Cosmetic science definitely has advanced since the days of Galen, yet most modern skin care products employ the basic formulation principles dating back to antiquity. Skin care products usually contain water (to help soothe and hydrate the skin), one or more fatty ingredients such as oils or synthetic chemicals (to help skin feel soft and to prevent moisture loss) and one or more ingredients added to coax oil and water into mixing uniformly with each other (emulsifiers). Scientists refer to such mixtures as emulsions. Mayonnaise is a prime example of a well-prepared emulsion, while oil-and-vinegar salad dressing forms a weak emulsion only upon vigorous shaking. Skin care formulations are called creams (if they have thicker consistency) or lotions (if they are thinner). Cleopatra was rumored to have bathed regularly in milk to maintain her legendary beauty. It is unlikely the Egyptian queen knew that soured milk contains lactic acid, one of the important skin care active ingredients called AHA’s (Alpha Hydroxy Acids). These compounds improve skin appearance and texture by a process called chemical exfoliation (a fancy term for skin peeling). Modern skin care products often include botanical ingredients (i.e. plant-derived materials such as aloe vera extract) and vitamins (e.g. tocopheryl acetate, a form of Vitamin E). Such ingredients contain anti-oxidants (chemical compounds that help protect the skin from environmental damage caused by pollution, cigarette smoke, sunlight and other factors). Arguably the most important anti-aging ingredients used in modern skin care products are sunscreens, chemicals designed to shield the user from the harsh effects of ultraviolet radiation found in sunlight. Recent studies have shown just how damaging solar radiation can be on human skin, leading to premature aging and, unfortunately, skin cancer. Products with high SPF values contain larger amounts of sunscreens and provide better protection against sun damage. Regardless of price point, using a modern skin care product with a high SPF and a high UVA protection value will help keep skin looking younger, something Ponce de Leon needed for that hot Florida sun.