Spa and massage therapists, gym trainers and other related professionals increasingly administer and / or prescribe aromatherapy on account of its multiple benefits. The therapy involves the application of essential oils which trigger the human body into releasing certain hormones with positive effects.
Four different ways of administering essential oils for aromatherapy are as follows:
- Massage
- Direct inhalation
- On the skin application through lotions and bath salts
- Indirect inhalation
When applied, essential oils cause the secretion of the following hormones in the human body:
- Endorphins act against pain and stress.
- Oxytocin plays a key role during childbirth. It is also a determinant of social behaviour such as trust, recognition, and anxiety.
As a result, the therapy is useful against conditions such as:
- Stress
- Insomnia
- Alopecia areata
- Pain
- Anxiety
- Agitation
Now, aromatherapy will deliver on its promises only if the correct method is used for essential oil extraction. Because only the right method will provide pure essential oils. Following methods are used for essential oil extraction:
- Carbon dioxide Supercritical Fluid Extraction (CO2 SCFE)
- Hydrodistillation
- Solvent Extraction
- Cold Press Extraction
- Maceration
- Resin Tapping
CO2 SCFE is among the better methods because it extracts the required compound (called target molecule - essential oil molecule in this case) in their relatively pure form. The process uses supercritical carbon dioxide (sCO2) as the supercritical fluid (SCF).
Following factors make sCO2 an ideal SCF during essential oil extraction:
- Low critical temperature of CO2 - 31.1 deg-Celsius - means the process temperature of CO2 SCFE is around the room temperature. This prevents the change in composition of essential oil molecules which are sensitive to heat.
Hydrodistillation uses heat and is therefore likely to thermally distort the target molecule.
- Supercritical CO2 or for that matter any SCF has selective solvent capacity i.e. at a particular pressure and temperature, it will dissolve only one particular target molecule. Few, if any, other molecules will get extracted. This maintains purity of extract.
Solvent Extraction is not a selective extraction method simply because the solvent does not completely separate from the target molecule.
A supercritical fluid is one at a:
- Pressure higher than its critical pressure; and
- Temperature higher than its critical temperature.
In this state, its properties can be similar to that of a liquid, a gas, or somewhere in between. For example, the:
- Density of an SCF is high - similar to that of a liquid.
- Viscosity and Surface Tension are low - as that of a gas.
Small changes in density produce large changes in its solvent power. Density rises and falls with pressure and temperature. At one particular pressure, the SCF will extract only one particular molecule while leaving other molecules largely untouched.
Most essential oils are safe to apply. They are more likely to produce unwanted reactions in people with preexisting conditions viz.:
- High Blood Pressure
- Asthma
- Psoriasis
- Hay Fever
- Eczema
- Epilepsy
But, as is the case with every coin, aromatherapy too has its down side in the form of side effects. These include:
- Rashes
- Headaches
- Skin Irritation
- Asthma Episodes
- Nausea
- Allergic Reactions
Doctors advise:
- Using essential oils under medical supervision;
- Applying essential oils through carrier oil; and
- Avoiding direct ingestion.
