More proof that beauty sleep is not a myth: A recent study conducted on mice shows that when the body's circadian rhythm (aka our biological clock responsible for sleeping and waking within a 24-hour period) is disrupted by, say, skimping on shut-eye, stem cell function is also disrupted. When stem cells follow normal circadian patterns, they know to defend our DNA against UV rays during the day and repair damage at night. When this balance is thrown off, skin is more susceptible to DNA damage and premature aging. What's more? A separate study done by MIT found that circadian rhythms in mice naturally decrease with age. Researchers prevented the slowing clock by boosting a gene called SIRT1.
While no skin care treatment can boost this gene, cosmetic brands have been using these recent findings to come up with new, topical ways to compensate when your circadian rhythm has gone rouge. But can they help? "I think we're just beginning to scratch the surface here," says David E. Bank, a dermatologist in Mount Kisco, NY. "But I don't think anything you're going to get in an over-the-counter cream is going to make much of an impact on resetting skin's circadian rhythm."
So what will help? Aside from getting adequate sleep, Bank says, "add the usual list of good guy ingredients -- retinoids, peptides, antioxidants, and sunscreen to your daily routine." During the day, aid skin's natural defenses by using broad-spectrum sunscreen (at least SPF 30) and antioxidants, which neutralize skin-damaging free radical damage. Try Neutrogena Age Shield Anti-Oxidant Face Lotion Sunscreen Broad Spectrum SPF 70 ($11; neutrogena.com). At night, boost skin's repair process with topical retinoids and/or peptides, which speed up cell turnover and boost collagen production. Try Garnier Ultra-Lift 2-in-1 Wrinkle Reducer Serum + Moisturizer ($17; ulta.com), which contains pro-retinol.