Skin: your biggest organ, all 20 square feet of it, and every square inch containing 19 million skincells—which the body replaces monthly. It's no wonder caring for your outer self can feel like such a big project. If it's any consolation, it's not all for vanity's sake, according to Alan Logan, ND, coauthor of Your Skin, Younger (Cumberland House, 2010). "Studies show skin damage often reflects a person's health and vitality," he says. Consider recent studies of twins, which found the younger-looking twin had healthier habits, less stress, and fewer medical problems—and ultimately lived longer. Here, get effective, nontoxic solutions for your top skin care concerns.

How does my diet affect my skin?

Your skin is what you eat, say experts: Food choices can cause and combat skin problems. "The body repairs and replenishes from the inside out," says Logan. "Nutrition makes a significant contribution to overall skin appearance." Start by cutting way back on sugar, which damages skin through a process called glycation, collagen distortion that promotes inflammation and oxidative stress. Also be conservative with vegetable oils, which can encourage breakouts. And foods cooked on high, dry heat (grilled, fried, or baked) have a similar inflammatory effect in the body because of preformed advanced glycation end products (AGEs), which also distort collagen.

Beauty fix: Minimize AGE damage by boiling, steaming, poaching, or stewing your foods. "We don't say, ‘never enjoy a grilled food,'" says Logan. But something as simple as poaching an egg, rather than frying it, can make a significant difference in AGE levels. In fact, high water content in the Japanese diet may be one reason why Japanese people tend to have fewer visible aging signs than Caucasians, says Logan.

Why am I developing acne?

Hormones aren't to blame just for teen acne; they're also the culprit behind breakouts that appear well after adolescence on the nose, forehead, and jawline. "When you reach 30, 35, or 40, your hormones start to change," says Maine-based holistic aesthetician Stephanie Tourles, author of Organic Body Care Recipes (Storey, 2007). "You have less estrogen cycling through your body." Plus, stress can cause sebaceous glands to pump out more, thicker oil and clog pores.

Beauty fix: Using a delicate clay mask, such as kaolin, twice weekly will help dry out oily areas, gently exfoliate, increase circulation, and unclog pores—without stripping protective oils. Also, keep a bottle of antibacterial, anti-inflammatory aloe vera handy and apply to breakout-prone areas a few times daily. "But keep your hands off your face," warns Tourles. Other acne-fighting tips: Clean your bacteria-laden phone, change pillowcases frequently, and get a monthly facial to clear pores.

Try: Aubrey Natural Herbal Seaclay with Goa Herb Oil Balancing Mask

Should I go without sunscreen so my body can make vitamin D?

With news that most Americans are deficient in the "sunshine vitamin," some medical experts advocate exposing skin to UV rays for 15 minutes or so daily, sans sunscreen. But unprotected exposure only helps your body make enough D when several variables—time of year, time of day, location, and skin type—work in your favor, according to a 2010 study. Also, because UV exposure can cause skin cancer and premature aging, it's wiser to take supplements, says Amy Wechsler, MD, author of The Mind-Beauty Connection (Free Press, 2008).

Beauty fix: Protect skin at all times, applying sunscreen to every exposed body part, including the neck and hands. Choose a broad-spectrum SPF 30 product that physically blocks UVA and UVB rays with zinc oxide or titanium dioxide, rather than harsh chemicals. The nanoparticles used in some mineral-based sunblocks to avoid the "white-face" effect and more effectively block UV rays pose little threat when applied topically, according to the Environmental Working Group. But avoid them in aerosol form, which increases risk of inhalation, an immune system concern, says Logan. The latest: Companies are reformulating with non-nano zinc that offers a similar consistency. For facial sunblocks, look for non-comedogenic or oil free on labels to avoid breakouts.

Try: Badger SPF 30 Sunscreen (non-nano); Elemental Herbs Zinc Sunstick SPF 30; Marie Veronique Organics Moisturizing Face Screen, Light Tint, SPF 30 

Do I need to moisturize daily?

Dry, itchy skin can lead to more than minor discomfort; low levels of ceramides—lipids that keep water locked in your skin—can cause inflammation that triggers psoriasis, eczema, even acne. Over the long haul, severe dryness can deplete skin's outer barrier, making it vulnerable to environmental damage and upping the risk for visible signs of aging, says Logan.

Beauty fix: Use an antioxidant-rich, plant-based moisturizer with nourishing shea butter, cocoa butter, or natural oils once daily, and twice daily during winter when ceramides need an extra boost. Take fish-oil supplements and eat fatty-acid-rich foods like salmon, shown to help relieve dryness and dermatitis. You can now find natural ceramides in skin-supporting supplements, too, which hydrate skin and reduce inflammation.

Try: Genuine Health Dermalipid; MyChelle Deep Repair Cream

Can natural ingredients fight wrinkles?

Yes, research-backed natural ingredients can stave off laugh lines and crow's-feet. But nontoxic products are free from harsh synthetics, so give them time—and appreciate small changes. "There is no fountain of youth," admits Logan. But "realistic improvements can make a subtle but very important difference in visible signs of aging."

Beauty fix: Use topical products with research-supported ingredients regularly—and consider simultaneously taking supplements that contain them, too. A hydrating, gel-like molecule, hyaluronic acid (HA) holds a thousand times its weight in water, drawing moisture from the air to fill wrinkles, says Tourles. And collagen improves skin's elasticity to keep it looking smooth; it, and other nutrients like vitamin C, also promote your body's own collagen manufacture.

Other wrinkle-fighting standouts: niacinamide (vitamin B3), sea buckthorn, coQ10, green tea, and resveratrol. Retinol, a natural form of vitamin A, is an antiaging go-to, but avoid sunscreens containing it or retinyl palmitate, which combined with sunlight may increase skin cancer risk, according to preliminary FDA data.

Try: Derma E Hyaluronic Acid Night Crème Intensive Rehydrating Formula; Now Solutions CoQ10 Antioxidant Cream; Reviva Labs Collagen Serum

Can I eliminate under-eye circles and puffiness?

Genetics, stress, sinus congestion, and eye rubbing can make the fragile eyelid and surrounding areas susceptible to discoloration and fine lines. "In Traditional Chinese Medicine, the liver is associated with eye health," says Tourles. "When it's not functioning properly or you've had an overdose of toxins, that will be reflected with yellowing of the eye and dark circles underneath."

Beauty fix: Cleanse the liver every morning with a large glass of warm water mixed with juice from half a lemon. Sip ginger or green tea throughout the day, and two to three times per week drink dandelion root tea, which helps rid the body of toxins and doubles as a facial cleanser (keep refrigerated; prepare a new batch every three to four days). Also consider a neti pot to rinse out nasal passages.

And be very gentle: This fragile area doesn't produce much of its own moisturizing sebum, lipids, or fats. Moisturize and soothe with ingredients close to your eye's natural sebum consistency, such as organic macadamia nut, jojoba, or sunflower oils. Look for anti-inflammatory ingredients, including seaweed, pomegranate, and aloe.

Try: SinuCleanse Neti Pot; Weleda Pomegranate Firming Eye Cream; Yogi Tea DeTox

Do I really need my beauty sleep?

Insufficient sleep and stress are biggies when it comes to acne and premature aging. "That old adage—get your beauty sleep—is real," says Wechsler. During sleep, your body produces human growth hormone (HGH, aka the antiaging hormone), which rebuilds and rejuvenates skin cells. But when you're anxious and losing z's, levels of the stress hormone cortisol skyrocket, disturbing the hormonal balance needed for a healthy complexion. Excess cortisol can also attack collagen—a protein that helps keep skin taut and wrinkle-free—causing inflammation-related issues, from joint pain to acne, says Shawn M. Talbott, PhD, author of Cortisol Control and the Beauty Connection (Hunter House, 2007).

Beauty fix: It only takes nine days (including two weekends) to get back on track, says Wechsler. Aim for eight hours of quality sleep nightly. Not feasible? Add an extra half-hour per week or take 20-minute naps. Other skin-saving habits: Exercise regularly to improve circulation and to release endorphins, stress-fighting neurotransmitters; and make time for friends. "Actual face time with friends has been shown to decrease cortisol levels," says Wechsler.

Worst skin care ingredients, how to tell if a product is working

Worst skin care ingredient offenders

Polyethylene glycol, aluminum starch octenylsuccinate, and oxybenzone in antiaging products and sunscreens.

Fragrance and triclosan in makeup, soaps, exfoliants,
and lotions.

Phthalates, parabens, and petroleum in everything from facial wash to moisturizers.

Highly concentrated glycolic acid in peels and antiaging products. Avoid products containing more than 5 percent glycolic acid.

How long does it take for a product to work?

Allow 28 to 35 days, the time it takes the outer skin layer to renew itself, before evaluating. Initial mild irritation is normal and often a sign your skin is detoxifying. But stinging, severe redness, or prolonged breakouts indicate you should stop using the product.