"7 Skin care rules dermatologists swear by"

Want smooth, pretty, age-defying skin? We thought so. Who better to learn from than the pros who think about dermal health all day long? From what you eat to when you wash your face, here are 7 small changes that can make a big difference in tone, texture, and overall glow.

1. Suds up at night

"The most important time to wash your face is before you hit the sack," says Doris Day, MD, a New York City–based dermatologist. Dirt, bacteria, and makeup left on overnight can irritate skin, clog pores, and trigger breakouts. Remove this top layer of grime with a gentle face wash (skin should feel pleasantly tight for 10 to 15 minutes post-cleansing), which also allows anti-agers to penetrate deeper for better results. Because oil production dips with hormonal changes in your 40s, cleansing twice daily can dry out your complexion and make wrinkles look more pronounced. To refresh skin in the morning, splash with lukewarm water.

2. Be UV obsessed

Nothing is more important than wearing sunscreen (ideally, SPF 30) every day if you want younger-looking skin. Even 10 minutes of daily exposure to UVA "aging" rays can cause changes that lead to wrinkles and sunspots in as few as 12 weeks. If your moisturizer isn't formulated with a built-in broad-spectrum SPF 30 sunscreen, be sure to apply one daily to block both UVA and UVB rays.

3. Manage stress

Emotional upheavals can make your skin look 5 years older than your chronological age, says New York City dermatologist and psychiatrist Amy Wechsler, MD, author of The Mind-Beauty Connection. Constant anxiety increases the stress hormone cortisol, which causes inflammation that breaks down collagen.

It also triggers a chain of responses that can lead to facial redness and acne flare-ups. To quell inflammation, eat antioxidant-rich foods such as berries, oranges, and asparagus. When you're feeling tense, Wechsler recommends a few minutes of deep breathing (inhale through your nose, hold for 3 counts, and release through your mouth).

4. Use a retinoid

Research shows that these vitamin-A derivatives speed cell turnover and collagen growth to smooth fine lines and wrinkles and fade brown spots. Prescription-strength retinoids such as Renova provide the fastest results--you'll start to see changes in about a month.

To help skin acclimate to any redness and peeling, apply just a pea-size drop to your face every third night, building up to nightly usage. Milder OTC versions (look for retinol) are gentler, although it can take up to 3 months to see noticeable results.

5. Update your routine

Altering even one thing in your regimen every 6 to 12 months jump-starts more impressive improvements in tone and texture. "When you apply products consistently, your skin slides into maintenance mode after about a year," says New Orleans dermatologist Mary P. Lupo, MD.

To keep your skin primed for rejuvenation, substitute a cream that contains alpha hydroxy acids for your prescription retinoid twice a week to boost the benefits. Or bump up your OTC retinoid to an Rx formula.

6. Eat omega-3s

These "good fats" in foods such as salmon, flaxseed, and almonds boost hydration, which keeps skin supple and firm.

The same isn't true of the saturated fat in dairy products and meats, which increase free-radical damage that makes skin more susceptible to aging. Limit saturated fat intake to about 17 g daily.

7. Exercise regularly

Studies find that women who work out regularly have firmer skin than similar nonexercisers. The reason: Exercise infuses skin with oxygen and nutrients needed for collagen production.

To keep your skin toned, make time for at least three 30-minute heart-pumping workouts per week.