The Science of Scents
Scents have the ability to change the way we see and feel the world around and within ourselves. Scents, or mainly essential oils, can impact our mood and cognitive functions, and aromacology is here to prove that!
What is aromacology?
Aromacology is the science that studies the influence of scents on human behaviour.
How do scents work?
Scents work in communication between the nose (olfactory bulb) and the brain (the limbic system). Any time we smell something, especially in natural fragrances like essential oils, we inhale volatile molecules called esters. These molecules are naturally present in plants, flowers, seeds, barks and roots and they help us to identify and characterize various smells.
How does the process look like?
The sense of smell comes from ultra-specialised sensory cells found in a tissue layer inside the nose. The process can be described in two stages:
1. Frist, the odour (esters) floats in the air reaching the nostrils and dissolving in the mucus (which is on the roof of each nostril). Underneath the mucus, in the olfactory epithelium, specialised receptor cells called olfactory receptor neurons detect the odour. These neurons are capable of detecting thousands of different odours.
2. Followingly, the olfactory receptor neurons transmit the information to the olfactory bulbs, which are located at the back of the nose. The olfactory bulbs have sensory receptors that are part of the brain which send messages directly to the most primitive brain centres where they influence emotions and memories (via the limbic system structures) and higher centres where they modify conscious thoughts (via neocortex) by helping us to distinguish different scents.
What is the limbic system aka “the brain of emotions”?
The limbic system is centrally involved in the mediation between a person’s recognition of an event and the resulting physiological reaction to it, mediated via the endocrine system. Stimuli are processed conceptually in the cortex and passed to the limbic system where with an array of neurotransmitters, they are evaluated and a motivational response is formulated. For instance, it can culminate in an energising or relaxing reaction, making you feel stimulated or at ease.
The limbic system works as a network of connected structures near the middle of the brain linked within the central nervous system. One of the structures of the limbic system is the olfactory bulb, which spreads the information captured by the sense of smell into the other structures of the limbic system. These structures work together to affect a wide range of behaviours including emotions, motivation, and memory. This system deals with instinctive or automatic behaviours and has little to do with conscious thought or will. The limbic system also deals with translating sensory data from the neocortex (the thinking brain) into motivational forces for behaviour.
Effects of essential oils on central nervous system: Focus on mental health. Phytotherapy Res 2020 doi.org/10.1002/ptr.6854