Most of us take care of our hair to, well, look good. What we don’t realize is how much deeper the hair-body connection goes.

“[Hair] reflects the long-term health of an individual,” says Nicole Rogers, M.D., a fellow of the American Academy of Dermatology and a Louisiana-based hair-restoration surgeon. “The luster, caliber and overall appearance of hair show how well a person is nourished.” And, in fact, it was used in the caveman days for mate selection, she adds.

“Nowadays, though, perfectly healthy hair can be overprocessed, in which case the effects of excessive heat styling, coloring or relaxing may damage the hair,” she says.

This damage is no small matter. “I have no problem with vanity, but it is more than that,” says Wendy Bazilian, Dr.P.H., R.D., coauthor of Eat Clean, Stay Lean (Rodale, 2015) and The SuperFoodsRx Diet (Rodale, 2007). “We should treat our hair as an extension of our body and know that there is impact in the habits we adopt and products we choose.”

It’s a balance. When it comes to washing and styling hair, less in care and products is often more—“the less we do for our hair, the better it will look,” says Rogers.

To Wash or Not?

Experts agree that there is no one answer to the best frequency to wash your hair. “It’s about how your hair and scalp respond to your routine,” says Temitayo Ogunleye, M.D., assistant professor of clinical dermatology at the University of Pennsylvania Health System. If you have no issues with your scalp—dryness, oiliness or irritation—then what you are doing is OK. If you start seeing dryness of the scalp or hair—dry hair may be brittle or break easily, or may not be growing as quickly (sometimes because it’s breaking)—perhaps you are washing too frequently.

Overwashing can cause dryness, says Ogunleye, because although shampoo removes buildup that may weigh down hair, it is a detergent made to strip oils from the hair.

A rule of thumb is to check in with how your hair looks. “I only recommend washing the hair as needed to reduce the appearance of oiliness,” says Rogers. “However, many people wash their hair as a way to style it. There isn’t anything wrong with this, so long as a person is not using too much heat afterward in the form of a blow-dryer or flat iron or curling iron.”

While a hair dryer may help you achieve your desired style, the energy and heat disrupt the chemical bonds of the hair, says Ogunleye, which over time can cause hair to break. In addition, the forced air action of the dryer can also further strip hair’s natural oils. If you have to dry, keep the dryer at “as low a temperature as possible in order to achieve the desired effect,” says Rogers.

Style, Au Naturel

In terms of styling, experts agree that you should be wary of chemicals found in hair products. “I don’t think women who buy these products realize that they haven’t been tested for safety,” says Erin Switalski, executive director of Women’s Voices for the Earth, a group focused on eliminating chemicals that harm our health and our community. “There are currently over 10,000 chemicals used in cosmetics, and the law doesn’t require they be tested for safety before [being] sold. The result is that manufacturers can put nearly anything they want in a product, including known carcinogens like formaldehyde.”

The big chemicals to steer clear of in hair products are formaldehyde, which is used as a preservative in shampoo and hair straighteners; parabens, another preservative used in shampoos; 1,4-dioxane, a contaminant from sodium laureth sulfate, found in products that create suds, including shampoo and hair relaxers; and fragrance, including phthalates, which is found in most hair products and is actually a mixture of dozens of different chemicals. “Unscented” products may still contain fragrance used to mask other odors in the product, so check the ingredient list for “fragrance.”

Good Nutrition

Equally important as how you wash and style your hair is what goes in your body. “Healthy hair and skin also come from a diet moderate in fat and varied in good whole foods,” says Bazilian.

Studies show that stress-induced hair loss, for instance, is associated with deficiencies in certain nutrients. When patients are losing hair, Ogunleye tests for vitamin D, zinc and ferritin (a blood cell protein that contains iron) levels, to start.

Vitamin D helps maintain healthy hair follicles. Zinc is used by glands that produce oils—not enough may lead to dry scalp, says Bazilian. Iron is important for producing hemoglobin and delivering oxygen to hair follicles.

Essential fatty acids and protein are important, too. According to Bazilian, getting enough good fats helps with hair’s moisture retention, shine and overall cellular support. Low protein, the building block of all tissue, could result in thin or dry hair, while adequate amounts help produce keratin, a protein that is the main component of hair.

Also essential: B vitamins (niacin, B12, B6 and B5), which help red blood cells supply oxygen to the scalp, and especially biotin, which assists keratin production.

Don’t be afraid of the oils and natural butters in these concoctions; they’re not likely to make your hair oily or weigh it down. In fact, natural oils can be food for the scalp, actually preventing dry or oily scalps and fending off dandruff.

Natural Hair Products to Try

Here are a few of our natural, sulfate-free favorites.

acureAcure Repairing Shampoo

This patent-pending blend includes organic argan oil to moisturize dry and damaged hair. Organic pumpkin seed oil—high in omega-3 and -6 fatty acids—adds shine.

natures-gateNature’s Gate Herbal Daily Cleanse Shampoo

Infused with natural botanicals that gently clean normal or color-treated hair without stripping or weighing it down, this shampoo is made with a blend of nettle, thyme, rosemary and lavender to promote healthy locks.

Burt’s Bees Very Volumizing Shampoo with Pomegranate

Formulated with pomegranate seed oil and jojoba protein (a natural moisturizer), this gentle shampoo easily rinses and adds shine and volume.

desert-essenceDesert Essence Coconut Shampoo

Offering natural nourishment for dry hair, the coconut oil infusion works with organic jojoba and olive oils to clean, moisturize and restore luster.

giovanniGiovanni 50:50 Balanced Hydrating-Clarifying Shampoo

Gentle for everyday use on normal to dry hair, this shampoo is infused with aloe vera, sunflower seed oil, lavender, rosemary and nettle to moisturize hair and smooth frizz.

Wondering about the safety of ingredients in your hair products? Check out the Skin Deep Cosmetics Safety Database (ewg.org/skindeep), where you can search thousands of products and ingredients to learn about scientific test results.