Is the Air You Breathe Your Skin's Biggest Enemy?

You can't usually see it and you probably don't feel it, but there's a lot of junk floating in the air. As we're now learning, it's hitting our skin hard. In just the last few years, scientists have been studying the dermal effects of particulate matter, gases, and other stealthy airborne attackers wafting around our cities, and it's pretty clear these pollutants are aging us.

One of the most convincing studies, conducted at the Leibniz Research Institute for Environmental Medicine in Germany, looked at how some 2,000 women had faired healthwise after 30 years of living with extra-grimy air in their polluted region. "We found a strong association between pigmentation spots on their cheeks and high pollution levels," says Jean Krutmann, M.D., the institute's director. Specifically, the women who were exposed to high levels of particulate matter, like soot and traffic pollution, had 20 percent more age spots and more pronounced wrinkles than those living in rural areas. Since the publication of these findings in 2010, experts have learned more about how pollution causes us to age. And what they've uncovered may motivate you to step up your skin care.

The Pollution-Aging Connection

Scientists from Olay, L'Oréal, and other major beauty companies have also begun exploring the link between pollution and skin problems. One Estée Lauder study, published in the Journal of Investigative Dermatology, showed that particulate matter causes oxidative stress in the skin, the result of damaging molecules like free radicals overwhelming your defense mechanisms and inducing DNA destruction, both of which can lead to premature signs of aging.

As its name suggests, particulate matter (PM) is minuscule dust or soot particles of metals, carbons, and other compounds; its sources include car exhaust and garbage incinerator smoke. (Since there's so much junk outside, make sure what you're putting inside is good for your skin too, like these 8 Best Foods for Skin Conditions.)

"We know that oxidative stress due to this pollutant directly damages skin's underlying structure," says Yevgeniy Krol, the scientific director for SkinCeuticals. That's mostly because the microscopic size of PMs enables them to easily penetrate skin. It gets worse: "Your body responds to pollution by increasing the inflammatory response. Inflammation helps destroy the bad guys but also everything around it, including the collagen and elastin that support your skin," Krol says. "So it's a double whammy."

The Filthy Five

Particulate matter is just one of the five types of air pollutants that trigger oxidative stress and age us. Another, surface ozone-a.k.a. smog-is highly toxic, Krol says. Surface ozone forms when two of the other five key pollutants, volatile organic compounds (VOCs) and nitrogen oxide, mix with another skin nemesis, ultraviolet (UV) rays. VOCs are chemicals released from car exhaust, paint, and emissions from industrial plants; nitrogen oxide gas is a by-product of burning fuel, such as from cars or factories. Rounding out the notorious quintet are polycyclic aromatic hydrocarbons, chemicals found in smoke and, again, car exhaust.

Chemical Warfare

As you stroll by traffic, various invisible particles can cling to and penetrate your skin. PM is typically measured at 2.5 to 10 microns, and pores are about 50 microns wide. It's like having an open goal.

What happens then: Your stores of natural antioxidants mobilize to neutralize the damaging molecules. But this drains your defense mechanism, leaving skin less equipped to fight off other damage, and eventually leads to the oxidative stress-inflammation one-two punch that Krol spoke of. (These glow-boosting Korean Beauty Products might help perk your skin back up.)

But that's only part of the problem. Pollution triggers genetic changes, says Wendy Roberts, M.D., a dermatologist in Rancho Mirage, California, who has studied pollution's impact on skin. PM causes cell functioning to go haywire, sending pigment-producing cells into overdrive. Plus, PM from cars triggers an overproduction of enzymes that break down collagen and trigger peptides, leading to more pigment production.

Meanwhile, ozone, in particular, damages the skin's surface; it attacks lipids and proteins that keep your complexion hydrated and your barrier function strong. As a result, your face becomes drier, and the damage opens the door for air-borne chemicals to enter. Throw in UV exposure, which makes PM more reactive, and the idea of living off the grid becomes appealing. (You can at least protect your skin from the sun with these Best Sunscreens for Skin Protection.)

How to Do Damage Control

Luckily, you don't need to give up urban life to thwart pollution's aging effects. First, wash your face at night. PM accumulates on skin over the course of the day, and the longer it sits and the more it builds up, the worse its effect, Dr. Roberts says.

• Use a gentle, moisturizing day cream such as Clarins Multi-Active Cream.
• Afterward, apply a topical antioxidant, which will bolster your internal army of pollution fighters. Look for those that contain ferulic acid or vitamin C, such as Lumene Bright Now Vitamin C Hyaluronic Essence.
• Next, keep skin hydrated with a moisturizer containing niacinamide, which helps build skin's pollution-blocking barrier, and vitamin E, which acts as a first line of defense. Olay Regenerist Micro-Sculpting Cream SPF 30 has both ingredients.
• At night, use products with resveratrol. "It activates your body's own antioxidant system and builds up your stores," Krol says. It's in SkinCeuticals Resveratrol B E Serum.
• Also, switch to a mineral-based sunscreen with zinc or titanium dioxide, such as Aveda Daily Light Guard Defense Fluid SPF 30. It protects against UV rays, which can increase the damage that pollution does. Wearing foundation and powder makeup helps too, because both add yet another layer of protection from pollution, Dr. Roberts says.
• New products targeting pollution also provide novel ways of blocking out bad stuff. For example, Shiseido's Future Solution LX Total Protective Cream SPF 18 contains invisible powders that trap pollution particles and stop them from adhering to skin. Stick with this streamlined routine and you'll see there's nothing more gorgeous than skin that's got its guard up.