Aromatherapy means to treat with aroma through inhalation (although it also encompasses the topical application of essential oils). Research has shown that we respond to aroma within one to three seconds. Scientists are just beginning to explore how aroma reaches and influences the human brain, emotions and body.

 

An oil's fragrance is created when vapor evaporates from it. The heavier the molecular weight of the oil, the less volatile it is (the less it will evaporate). Oils with lighter molecular weights, evaporate or 'flash off' quickly. Therefore, the scents of lavender or geranium last only about 20 minutes. Heavier oils such as myrrh, frankincense, sandalwood, and patchouly evaporate slower, and therefore, their scent lasts longer.

 

As the molecules in a fragrance evaporate into the air and are inhaled, olfactory membranes (protected by the mucous lining of the nose) capture them. These membranes are lined with receptor cells that can be considered hair-like extensions of nerve fibers. Each fragrance molecule fits itself into specific receptor cells, like a puzzle piece. The stimulation by odor molecules causes the receptors to trigger electrical impulses to different parts of the brain. These nerve impulses are transmitted to the limbic system of the brain. The brain then sends more impulses to different parts of the body, depending on type and function.

 

 

The limbic system is directly connected to the parts of the brain that control heart rate, blood pressure, breathing, memory, stress levels, and hormone balance. Because of this, essential oils can have profound physiological and psychological effects.

 

Have you ever noticed that a scent or fragrance can instantly evoke a memory or an emotion on an unconscious level? This is because the sense of smell is the only one of the five senses that is directly linked to the limbic lobe of the brain - the emotional control center. Emotions such as anxiety, depression, fear, anger, as well as joy all emanate from this region.

 

 

The limbic lobe can also directly activate the hypothalamus - the "master gland." The hypothalamus functions as the hormonal control center of the body. It releases chemical messengers that affect the production of growth hormones, sex hormones, thyroid hormones, and neurotransmitters.

 

Essential oils, through their fragrance and molecular structure, can directly stimulate both the limbic lobe and the hypothalamus. In this way, essential oils can exert a profound effect on the body and the mind.