Valerie Cooksley defines aromatherapy as “the skilled and controlled use of essential oils for physical and emotional health and well being.” I would translate that as the careful use of essential oils to maintain and improve physical health as well as to affect moods (calming, energizing, clarifying, etc.).

Essential oils are volatile oils that are extracted from plant matter. They contain the aromatic compounds from the plant. Aromatherapists maintain that these compounds have therapeutic value. Plants have been used medicinally for thousands of years. There is some discrepancy as to whether the ancient Egyptians and Chinese first used essential oils, or if it truly began with the invention of the still circa 800 C.E.

Some of what we know today about the application of essential oils is based on historical use. There are, however, modern research studies being conducted on essential oils and these studies have found that many essential oils have anti-microbial effects, and some essential oils do indeed alter a persons mood. Modern science is verifying history.

Essential oils can be applied topically or can be inhaled. Essential oils are very concentrated and they should never be applied to skin without being significantly diluted. As the focus of this website is diffusion of oils, we will focus on the inhalation route of entry.

Nasal route of entry

Aromatic molecules enter our nose and hit the olfactory membranes in the nasal passages, which sends messages to our brain via nerves. Our sense of smell, and our responses to aromas are linked to the limbic system of the brain. The limbic system is responsible for, among other things, our emotions and behavior. It is also influences the endocrine system (hormones). The limbic system is also connected to the brains pleasure center. So, when we smell a certain aroma it makes sense that it can affect our emotional states given that it stimulates the parts of the brain associated with emotions and hormones.

Sometimes, these feelings are associated with prior experiences with a particular scent (i.e. the smell of cloves reminds you of the dentist office, which may cause anxiety!). If you are looking to benefit from the emotional benefits of aromatherapy, then the nasal route of inhalation is important. All of the diffusers listed in this website will provide you with aromas.

Inhalation via the lungs

When aromatic molecules are inhaled into our lungs, they can cross into the bloodstream through the alveoli. From there they are transported throughout the body via the circulatory system. Any compounds the body cannot use will be excreted.

It is worthwhile to note here that essential oils do not need to enter the body to do us good. As previously mentioned, some essential oils have been documented to have anti-microbial effects (e.g. anti-bacterial, anti-viral, anti-fungal). What is even more exciting, is the possibility that superbugs such as MRSA may be susceptible to essential oils. Trials have been conducted diffusing essential oils in a burn unit and the incidence of MRSA dropped. What this may mean is that when we diffuse essential oils into the atmosphere, they may literally clean the air. One recent study found that lemongrass and geranium diffused in an office reduced airborne bacteria by 89% and also inhibited bacterial growth on surfaces (Letters in Applied Microbiology, April 2009).

Overuse of antibiotics and our modern fetish with anti-microbial cleaners and hand sanitizers has contributed to weaker germs being killed and the strongest surviving, perhaps making us even sicker than we were before since the remaining bugs are more difficult to kill. The possibility that an essential oil can clear the air without causing anti-microbial resistance is a very exciting thought indeed!