Smell and be well:  essential oils and the brain

Nick Carter, a Kentucky hound, was the greatest tracker in history, with a record in excess of 600 successful arrests. Born in 1899, he began a partnership with Captain G V Mullikin of Lexington, Kentucky which led to more than 150 criminal convictions. He was a bloodhound, a breed which holds the ultimate record for tracking: the location of a missing family in Oregon after more than 300 hours of their disappearance, a record held since 1954. 

But ‘sniffing’ is more than just smell, it is critical for survival in all mammals – for finding and acquiring food and water, detecting predators or other threats, contributing to social interaction and for reproduction. 

So, we could ask – can the same be said of us humans? How important is our sense of smell and how good is it? It’s a popular belief that smell is the least of our senses compared to other animals and plays little part in our lives. Modern research has shown that in fact our sense of smell, millions of years old, is indispensable – not just to our survival but amazingly, to our social and sexual relationships, our appetite, our eating and drinking behaviour, our well-being and even our brain health. Our nose, it turns out, is a priceless asset to our life-long wellbeing.

Have you ever wondered what makes up the wonderful fragrance of your favourite perfume, your skin cream, the flavourings of delicious food? So important is our smell to us that worldwide we spend over $33 billion dollars (£20 bn) per year on these products. And the essence of these preparations is the wonderfully smelling extracts of aromatic plants – quite simply called ‘essential oils’ (EOs). They are a genius of nature, a vital natural resource from the botanical world. Essential oils are very small and complex ‘organic’ molecules (ie. based on carbon atoms) called ‘terpenes’, the largest class of natural products in the world.  But it’s not just their smell.  They’ve been shown to have antimicrobial, disinfectant, anti-inflammatory and health promoting properties. Moreover, recent research shows they can have dramatic effects on our brain health.  

Everyone knows the relaxing effect of cut flowers and garden plants. These effects are due to ‘anxiolytic’ essential oils which change our mood and level of arousal. Amongst such plants are lavender, sweet orange, sandalwood, rose, bergamot and Roman chamomile to name a few. There is also growing evidence to suggest that lavender oil may be an effective treatment for several neurological disorders, the evidence showing it has anxiolytic, mood stabiliser, sedative, analgesic, anti-convulsive and neuroprotective properties. We even know how some EOs work. Ylang-ylang lowers the dopamine levels in the brain and ‘ups’ the levels of serotonin.

Some essential oils reduce anxiety and depression reliably without side effects associated with many prescribed pharmaceuticals and are more effective. For example, sweet orange and bergamot oil both show both anxiolytic and antidepressant qualities, plus lavender is a safe-yet effective alternative to benzodiazepines therapy for generalised anxiety. 

It’s not just mood. We now know that some EOs undoubtedly affect our thinking skills. Some examples are rosemary, sage and Spanish sage which enhance cognitive performance, as does peppermint which improves memory, alertness and impedes mental fatigue.

Further, many EOs show strong anti-inflammatory, antioxidant and neuro-protective effects, such as chamomile, clove, garlic, ginger, patchouli, peppermint, sage, thyme and ylang-ylang.  Many of these intervene through their powerful neurotransmitter influence. In Alzheimer’s disease, many EOs have been found to have profound pharmacological effects, such as anti-cholinesterase, anti-amyloid (Aβ) and anti-neurofibrillary tangle activity. EOs also reduce agitation (melissa) and reduce depression (coriander).  According to the US National Library of Medicine global trials register, there are 349 clinical trials involving EOs of which 16 are investigating Alzheimer’s disease. 

Our sense of smell gives us an unparalleled and peerless window on an unseen world. It mesmerises us, woos us and rewards us – in the words of Marian Bendeth, “…like cocktails without the hangover, like chocolate without the calories, like an affair without tears, like a vacation from which you never have to come back”. Our sense of smell is simultaneously under-used and under-valued. In partnership with essential oils, we should nurture it, train it and use it. 

Together, they are our secret weapon in the life-long health of our brain.