The healing power of plants

The plant-extracted, highly concentrated liquids have historically been selling points in beauty and cleaning products—and now research proves that when inhaled properly, they're also good medicine, says Brent Bauer, M.D., director of the Complementary and Integrative Medicine program at the Mayo Clinic.

Dozens of studies have found that essential oils can both protect your long-term health and relieve symptoms of common maladies. They can help lower stress levels, relieve pain, improve mood, and quell cravings and nausea. Essential oils have even been demonstrated in lab studies to kill flu, E. coli, and cancer cells, the Fox News reported.

"Research shows that, when inhaled, the oils activate your brain's hypothalamus, which controls hormones, energy, and drive," says Illup Louis Gravengaard, a director of alchemy at I AM Enlightened Creations, an aromatherapy and healthy-lifestyle company. Different essential oils trigger different responses in the brain, which, in turn, directs your nervous system.

The findings are promising, but they come with a caveat: "Whatever is powerful enough to exert a beneficial effect in the body is powerful enough to exert a negative effect," says Bauer. Essential oils release volatile organic compounds (VOCs), off-gases often linked to paints and pesticides. So while, for instance, moderate exposure to essential oils can be heart-healthy, prolonged exposure can pose cardiac risks.

The key is staying within a 15-to 60-minute sweet spot—never breathe in essential oils for more than one hour at a time. Always follow the instructions on the bottle, and if you are taking any medications or suffer from a chronic health condition, ask your doctor before you start practicing aromatherapy. Just as with any other medicine, essential oils must be used correctly to yield huge health rewards.

Follow these tips to make sure you purchase genuine products.

--Beware the blanket aromatherapy label, often slapped on diluted oils laced with synthetic fragrances.

--Look for 100 percent pure and organic oils free of fillers, pesticides, and synthetic chemicals. If a label says therapeutic grade or steam distilled, even better.

--Most essential oils have long shelf lives—more than a year if stored in a cool, dry place. If the shop you're in is hot or humid, buy elsewhere.

A diffuser is the most effective way to unleash essential oils into the air, but if you don't have one (they run from $25 to $200), you can drip oil into a bowl of steaming hot water. In either case, use one or two drops of one oil at a time. Stand a few feet away and take 10 deep breaths, then breathe normally. If you stick within the safe time limit and open a window when you're done, you can practice aromatherapy every day.

Essential Oil: Sage

Best for: Blood-Pressure Reduction

Bonus perks: Helps amp up memory and attention

Essential Oil: Peppermint

Best for: Stress Relief

Bonus perks: Reduces both fatigue and (score!) chocolate cravings

Essential Oil: Orange

Best for: Decreasing Anxiety

Bonus perk: Elevates mood

Essential Oil: Rosemary

Best for: Enhancing Brainpower

Bonus perks: Boosts energy; lowers fatigue