Our nose – a miniseries on our five primary senses (part 1)
We use our five primary senses, sight, hearing, touch, smell and taste to obtain information about our surroundings. The brain does an amazing job in processing this information. Due to the brain’s unique remodeling ability, known as its “plasticity”, when certain pathways are “closed off”, it can: take another route, form new connections, or use unused and weak ones. These are the ways in which the brain supports us by responding to stimuli from the surrounding, making the most of our senses in almost every situation.
The brain rewires itself when a sense is lost
When certain signals don’t reach the brain (anymore), the other senses expand and are then represented all the more strongly. You have probably heard that people without sight may compensate for this through enhanced abilities such as heightened sense of: hearing, taste, touch, and smell as well as cognitive functions.
Let’s cherish our nose
In this miniseries, I will start with the olfactory sense, the “Cinderella of our Senses” (1), which, in my opinion, cannot be appreciated enough. Smell silently shapes our lives. Many of us take the sense of smell for granted and may not realise how fundamental it is to everything we experience.
Our sense of smell is linked to appetite
People who are overweight are often less sensitive to smells than thin people (2) (3). The good news is that we can use dieting and aromatherapy to rekindle our sense of smell and lose weight. We can sniff a fruit, like an orange or a pineapple to curb unwanted cravings – without consuming any calories. This may help us seek a low calory fruit snack instead or remind us to make healthier eating choices. Alternatively, we can sniff one of our favourite non-food scents, like lavender, wood or clean cotton, to distract us or remind us of something completely different.
Our sense of smell is linked to brain health
Our sense of smell can influence our lifespan
One reason why a poor sense of smell is associated with earlier death is that without our nose we are less likely to be able to detect environmental dangers, such as: smoke, food spoilage, and dangerous chemicals. Another important finding is that we are not able to smell when we are in deep or dream sleep. This has implications regarding house fires and the necessity of having auditory smoke alarms (6).
Our sense of smell is the only sense directly wired to the emotional center of our brain
None of our other senses are. Smell evokes our most emotional memories, both good and bad (7).
Our body odor is as unique as our fingerprints
It is the external representation of our genes. Genetically determined odor types help in distinguishing individuals from each other as well as in the selection of a prospective partner. Research has shown, that choosing a potential partner is largely based on smell (8). A woman’s sense of smell is at its peak during the few days each month when she is fertile and ovulating. But beware: hormonal contraceptives and artificial fragrances could mask a man’s true scent. Both could hide or confuse sensory signals and cause women to be attracted to genetically incompatible men (9).
How can we appreciate our nose?
- By training our nose and increasing our olfactory ability. When we actively sniff, all scents become more intense. The good news is that active sniffing has even been found to restore lost olfactory neurons.
- By looking around when we smell something and discovering what it is associated with. The more we know about scents the better we can smell them.
- By using aromas to enrich our lives. For example, taking a new fragrance on a special trip and then when we want to remember that trip, we sniff it!
- By taking the time to pause and smell everything that comes our way.
Developing awareness of our senses is a way to connect more with ourselves and open the doors to countless possibilities for healthy choices, self-exploration, and positive change.
References and links:
(1) The Cinderella of the Senses: Smell as a Window into Mind and Brain? Ann-Sophie Barwich — Visiting Assistant Professor in the Cognitive Science Program at Indiana University Bloomington
(2) A Decreased Ability to Smell Is Linked to Obesity – by Alan S. Berger, M.D. | Sep 20, 2019 | Obesity
(3) Systematic review of olfactory shifts related to obesity – by Mei Peng, Duncan Coutts, Ting Wang and Yusuf O. Cakmak | Nov 19, 2018
(4) Olfactory Dysfunction as a Global Biomarker for Sniffing out Alzheimer’s Disease: A Meta-Analysis – by Alisha M. Kotecha, Angelo D. C. Corrêa, Kim M. Fisher, and Jo V. Rushworth | 2018
(5) A clinical approach towards smell loss in Parkinson’s disease by Antje Haehner, Thomas Hummel, Heinz Reichmann | 2014
(6) Effects of ageing on smell and taste by J.M. Boyce and G.R. Shone | 2006
(7) Psychology and smell
(8) Evidence that humans prefer genetically dissimilar partners based on scent by Bob Yirka | March 20, 2019
(9) MHC-correlated odour preferences in humans and the use of oral contraceptives by S. Craig Roberts , L. Morris Gosling , Vaughan Carter and Marion Petrie | Aug 12, 2008