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Emotional Rescue: our sense of smell is the key to survival

Apparently, birds and mammals have brains up to 10 times larger, relative to body size, than those of reptiles and other animals’ (

We do a lot of thinking, so that makes sense, right? However, it’s not necessarily the reason, scientists say. Commenting on research published in Science Journal in 2011, palaeontologist and research co-author Zhe-Xi Luo reveals we evolved larger brains ‘for a more urgent and more basic need—our sense of smell was far more important.’

The smell is one of the earliest senses to develop while babies are still growing in utero. Helping newborns locate their mother’s breast, smell is literally the key to survival. So it stands to reason that this primordial yet sophisticated sense is one of the most important we possess. Scents and odours evoke memories, warn us of danger, increase or decrease heart rate, and they have the power to affect our moods and emotions in profound ways.

For all of you who choose Koala Eco, this isn’t necessarily fresh news. So many of you use our products not only because they don’t harm the planet, but also for the therapeutic benefits associated with the natural essential oils in our ingredients. But when I recently came across some research examining the links between smell and wellbeing, I discovered some fascinating facts I wanted to share.

Oxford University’s Mikiko Kadohisa (2013) cites several studies examining the effects of odour on emotion. One reported ‘effects of citrus fragrance on the improvement of psychological states and immune function of patients with depression.’ Others identified that ‘green odor [sic] … elicits pleasantness from humans.’ And, maybe most helpful of all, orange and lavender were proved to ‘reduce the anxiety of patients in a dental office.’ Something worth bearing in mind if any of you are planning a trip to the dentist!

Sandra T. Weber and Eva Heuberger (2008) from the University of Vienna carried out a series of tests involving indoor and outdoor settings, and natural and synthetic fragrances. The first experiment, which took participants to smell the flowers in the University’s Duftgarten (Fragrant Garden) showed that ‘complex, natural odors [sic] derived from blooming plants increase calmness, alertness, and mood, in humans in a natural, outdoor setting.’  From the study’s overall results, Weber and Heuberger deduced that natural odours (but significantly, not artificial ones) ‘improve affective states in humans in a natural, outdoor setting independent of visual input.’ So you don’t even have to see the plants in order to derive emotional benefit from their scent.

It’s no accident that we use the uplifting and stress-relieving essential oils from citrus like Mandarin (Citrus reticulata) and Pink Grapefruit (Citrus paradisi), and from herbs like the soothing lavender (Lavandula angustifolia) and refreshing peppermint (Mentha piperita) in so many Koala Eco products. They’re 100 percent pure, nothing artificial. So perhaps if you can’t manage to get to a ‘fragrant garden’ or bush block right at this moment, a light misting of our Pillow and Linen Spray with Eucalyptus, Peppermint and Rosalina will sustain you until you can!


Gibbons, A., 2011. ‘Mammals' Big Brains Began With a Sniff.’

Kadohisa, M., 2013. ‘Effects of odor on emotion, with implications.’ Frontiers in Systems Neuroscience.

Weber, S. T. and E. Heuberger, 2008. ‘The Impact of Natural Odors on Affective States in Humans.’ Chemical Senses 33.


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