Save Our Skin

Hannah Morrill and Judith Newman, Allure magazine

When we think about our skin (and God knows we do), we think hopefully of descriptors like "radiant," "glowing," and "luminous." We generally don't think of a beefy bouncer at a nightclub. But in fact, that's what it is. Skin acts as a defense against the skanks and losers-er, bacteria and viruses; it keeps the undesirables out and the good guys in. Foreign chemicals, irritants? You're not on the list. Water? C'mon in. Or at least that's what skin is supposed to do. When this system breaks down, it's not only our looks that suffer; it's actually our health, too. That's why there is suddenly an explosion of interest in what dermatologists call "skin-barrier function"-the capability of the skin to perform its gatekeeping services effectively. There's increasing evidence, too, that a healthy barrier is essential for aging well.

See more: The 6 Most Flattering Haircuts for Round Faces

It's not just people with skin conditions like psoriasis and eczema who have to deal with a screwed-up skin barrier. Normal skin is subject to barrier disruption all the time: dryness in the winter. Sun and irritation from pool chemicals in the summer. When the barrier is damaged, we become more susceptible to a whole host of problems. More bacteria get in. Chronic inflammation can ensue. That can lead to impaired antioxidant defense and higher levels of free radicals, which can result in premature aging. And overall, when the skin is in a weakened state, many products will irritate it, precluding the use of some more powerful ingredients. Moreover, the simple fact of getting older makes the skin barrier slower at recovering from assault, says Peter M. Elias, a professor of dermatology at the University of California, San Francisco and the author of Skin Barrier (Taylor and Francis). Add to that a lifetime of sun damage, if you're a tanner or a burner, and you've really got yourself a Situation.

See more: Top 21 Drugstore Beauty Bargains

Here's the unfortunate thing about damaging the skin barrier: We often do it ourselves. Many of us have skin-care rituals that tend toward the overzealous. If our skin routines were newscasters, they'd be less Brian Williams and more Glenn Beck. Changing routines (and perhaps some products) may not return you to the skin of your youth, but it could help make your skin worthy of glowing adjectives. Just watch out for these five common ways of preventing the skin barrier from doing its job.

See more from Allure:
The Top 14 New Summer Hair Ideas
The 12 Best Eye Creams
2012 Readers' Choice Awards
10 Hairstyles That Make You Look 10 Years Younger