The magic of aromatherapy

How scents influence our brain

A touch of history

Aromatherapy is nothing new. With origins in ancient cultures such as Egypt, China, and India, aromatherapy uses natural scents to heal the body, mind, and spirit. Traditionally, essential oils and fragrances were used to treat problems such as headaches, eczema, and anxiety. Even today, fragrances, both natural and synthetic, are used in many consumer products such as candles and perfumes.

From the nose to the brain

Our sense of smell is deeply rooted in evolution, ensuring the survival of our ancestors and influencing our daily lives to this day. The process begins when odor molecules bind to the receptors in our nose. This triggers a chain of events that ultimately generate an electrical signal in the brain. This signal is then interpreted by specialized areas of our brain—such as the hippocampus and amygdala, which are responsible for emotions and memory.

The power of EEG in aromatherapy

To understand how scents affect our brains, researchers use EEG technology. EEG records the brain's electrical activity, and by applying the International 10-20 System, electrodes can be precisely placed on the scalp. This allows scientists to see how our brains react to different scents. For example, some studies have shown that scents like lavender and rosemary can influence EEG activity in specific patterns. Here 's a relevant study on this topic.

A look into the future

With advances in EEG technology and methodology, we can delve deeper into the mystery of how scents affect our mood, memories, and even cognitive abilities. It's amazing how the influence of something as intangible as scent can penetrate deep into the functions of our brain. And as we continue to explore, we'll surely learn even more about the fascinating connection between scent and the brain.

conclusion

Aromatherapy and scientific research into the effects of scent on our brains open up a world of possibilities. From healing to relaxation, from memory to emotion—the magic of scent is deeply rooted within us, waiting to be explored.

Results. Furthermore, there are interindividual differences in odor processing and response, which can be influenced by gender, age, and genetic factors. It is also important to consider that the response to a particular scent is influenced not only by the scent itself, but also by the memories and emotions associated with it.

Some scents can have both relaxing and stimulating effects, depending on the dose and context. For example, lavender can be relaxing in small amounts, while it can be stimulating in larger amounts. There are also differences in scent perception and preference between individuals, suggesting that a personalized approach to aromatherapy may be most effective.

The interaction between taste and smell is another important factor to consider, especially in the food and beverage industry. Combining certain scents with flavors can help enhance the taste and overall experience of a product.

Current research suggests that aromatherapy may be a promising method for improving psychophysiological well-being. However, much research remains to be done to understand the precise mechanisms by which scents affect the brain and to determine the optimal scents and concentrations for different therapeutic applications.

It is also important to note that while many studies report positive effects of essential oils, there are also potential side effects and risks, especially when used in large quantities or for extended periods of time.

In summary, current research suggests that scents can have a powerful effect on the human brain and overall well-being. With further research and a deeper understanding of the underlying mechanisms, scents could be used even more specifically in the future to achieve health benefits and improve overall well-being.

substance	EEG effects	Effect	reference
Neroli and grapefruit oils	Increased alpha and theta activities	Reducing cortical deactivation or promoting a relaxed state	[79]
Alcohol in low doses	Decrease in theta power in both hemispheres under high dosage	According to the working memory requirement	[81]
Frankincense and rose oil	Increased fast alpha activity in bilateral posterior regions during frankincense exposure	Influence on cortical function and inhibitory processing of motor responses	[14]
Citrus bergamia oil	Negative changes in the ratio of low to high frequency in the music, aroma and combination groups compared to the control group	Effective method for relaxation by listening to soft music and inhaling Citrus bergamia essential oil	[90]
Abies sibirica essential oil	Increased theta activity after screen task	Prevention of screen exposure and mental health disorders	[15]
Lavandula angustifolia	Good sleep quality: decrease in alpha waves in occipital and parietal regions, increase in theta and beta waves in frontal and occipital regions; Poor sleep quality: increase in theta waves in all cranial regions	Beneficial effect for adult women with sleep disorders	[98]
Lavender oil	Increase in theta and alpha activities	Relaxing effect from inhaling lavender oil	[12]
Zizyphus jujuba seed oil	Increased fast alpha activity in left prefrontal, right prefrontal and left frontal regions	Increased attention and relaxation	[99]
Mentha arvensis L. f. piperascens aerial parts	Increased relative fast alpha activity, decrease of gamma and spectral cutoff frequency by 90%	Reduction of mental stress	[100]
Jasmine oil	Increased beta waves in anterior-central and left posterior regions	Increased well-being, activity, freshness and romance	[102]
Ylang-Ylang essential oil	Prolongation of P300 latencies	No effect on information processing in patients with TLE	[63]
Essential odors (mint and lemon) and commercial odors (citron verbena, lize, melody and rozan)	Influence of EEG waves in some subjects	Essential scents have a stronger effect than commercial scents, and women are more sensitive than men	[35]
Pan-roasted Japanese green tea (Koushun and Kouju)	Influence of Beta-1 in the right frontal region by Kouju	Improve memory performance	[103]
Magnolia kobus flower	Decrease of absolute alpha waves in left parietal region	Increased alertness and concentration of the brain	[101]
Strawberry aroma (food) and lily of the valley scent (non-food)	Specific potential maps for both conditions	Food odor associated with reward processing, non-food odor reflects odor properties without reward	[104]
Hyperbaric oxygen exposure	Decrease of fast delta waves and increase of alpha waves in posterior regions	Diving-related problems due to oxygen toxicity	[151]
Lemon, peppermint and vanilla	Statistically significant differences in theta waves between different odor conditions	Stimuli can influence the frequency characteristics of the brain’s electrical activity	[16]
Isomers of limonene and terpinolene	(+)-Limonene: Increase in relative high beta waves in the right temporal region; Terpinolene: Reduction of tension and increase in relaxation and stabilization states of brain function, reduction of relative medium beta waves and increase of relative fast alpha waves in the right prefrontal region		[17]
Essential oil from the roots of Inula helenium	Decrease in theta (except T3), beta (Fp1) and mean beta waves (P4) as well as relative theta waves (Fp1, Fp2, F3 and F4)	Improving the brain's attention state	[60]
Lavender and Bergamot	Increase in absolute theta in right prefrontal region, significant differences in relative fast and slow alpha waves	Stabilization and relaxation of the physical and mental state	[ 64 ]

Effect of aroma inhalation on human psychophysiological functions.

p. no.	Odorants	Psychophysiological changes	reference
1	Rosemary and geranium oil	Inhalation of geranium oil – both condition and trait values ​​were significantly reduced.	[ 113 ]
2	Ylang-Ylang, Orange, Geranium, Cypress, Bergamot, Spearmint and Juniper	Cypress produced a positive impression after physical work and juniper left a positive impression after mental work.	[ 114 ]
3	Orange	Relaxing effect – reduced anxiety, a more positive mood and a higher level of calm.	[ 115 ]
4	Rose, jasmine and lavender	Inhaling favorite smells suppresses the activity of sympathetic vasoconstrictors in the muscles and dampens the rise in blood pressure by acting on the central nervous system above the midbrain.	[ 116 ]
5	Enantiomers of limonene and carvone	Carvone – subjective restlessness. Prolonged inhalation of fragrances affects the parameters of the autonomic nervous system, as well as mental and emotional state.	[ 120 ]
6	Peppermint, jasmine, ylang-ylang, 1,8-cineole and menthol	Essential oils or their components affect basic forms of attention behavior, especially of a psychological nature.	[ 119 ]
7	lavender	Lavender fragrances have been linked to a reduction in psychological stress and increased arousal rates.	[ 122 ]
8	peppermint	Improved physical performance, more push-ups and faster running.	[ 135 ]
9	Isovaleric acid, thiophenol, pyridine, l-menthol, isoamyl acetate and 1,8-cineole	Autonomic variations in response to olfactory stimuli – along two main dimensions of pleasantness and arousal.	[ 118 ]
10	Pepper oil, tarragon oil, fennel oil or grapefruit oil, rose oil or patchouli oil	Inhalation of fragrances such as rose oil or patchouli oil resulted in a 40% decrease in relative sympathetic activity.	[ 117 ]
11	Lavender oil	Treatment of agitated behavior in patients with severe dementia.	[ 123 ]
12	Peppermint oil, jasmine oil and dimethyl sulfide	The peppermint smell reduced workload and effort and increased self-assessed physical performance and energy.	[ 136 ]
13	Lavender and rosemary oil	Lavender led to a significant reduction in working memory performance. Rosemary led to a significant improvement in overall memory quality.	[ 124 ]
14	Rosemary and lavender oils	Both rosemary and lavender scents were associated with lower mean scores on the fatigue and lethargy subscale compared to the control group.	[ 125 ]
15	Lavender and Neroli	Relaxing odors reduced heart rate and skin conductance, while stimulating odors produced the opposite effects under the same conditions.	[ 126 ]
16	Lavender and rosemary oil	Altered affective appraisal of the experience and resulting retrospective assessment of treatment-related pain.	[ 127 ]
17	Lavender oil	In men and women, the proportion of deep or slow-wave sleep increased and rapid eye movement sleep decreased.	[ 128 ]
18	Peppermint oil	Reduced fatigue and improved mood and was rated as more pleasant, intense, stimulating and intoxicating than water.	[ 137 ]
19	Synthetic peppermint scent	Performance improvement in the presence of peppermint odor when response matching was incompatible but not in the compatible condition.	[ 139 ]
20	Jasmine tea, lavender, ( R )-(−)-linalool and ( S )-(+)-linalool	Jasmine tea, lavender and ( R )-(−)-linalool increased the positive mood state.	[ 152 ]
21	Orange and lavender	Reduced anxiety and improved mood in patients waiting for dental treatment.	[ 129 ]
22	Peppermint oil	In case of daytime fatigue, peppermint oil can actually reduce drowsiness.	[ 140 ]
23	Lavender and jasmine	During breaks – higher concentration levels for the lavender group	[ 133 ]
24	Ylang-Ylang oil	Calmer and more relaxed.	[ 142 ]
25	Chewing and caffeine	Compared to chewing, caffeine resulted in improved speed and accuracy in cognitive tasks and increased attention.	[ 141 ]
26	Roman chamomile essential oil	Calming effect	[ 143 ]
27	Lavender, chamomile, rosemary and lemon	An aromatherapy massage has positive effects on anxiety and self-esteem.	[ 134 ]
28	With or without bath oil with lavender scent	Mothers were more relaxed and smiled. Infants cried less and spent more time in deep sleep.	[ 130 ]
29	lavender	Increased relaxation.	[ 131 ]
30	Lavender and chocolate scent	Ortho- and retronasal odor presentation – the route of odor presentation has a direct impact on the enjoyment of food and beverages.	[ 145 ]
31	Ylang-ylang aroma, peppermint aroma	Peppermint enhanced memory, while ylang-ylang impaired it; peppermint increased alertness, while ylang-ylang decreased it.	[ 141 ]
32	Aroma of Heliotropin	Reduced sleepiness and improved refreshment upon awakening in participants suffering from insomnia symptoms.	[ 146 ]
33	Lavender oil	The stress level and pain intensity during needle insertion were reduced.	[ 132 ]
34	1,8-cineole after exposure to rosemary aroma	Cognitive tasks are significantly related to the concentration of absorbed 1,8-cineole after exposure to rosemary aroma.	[ 147 ]
35	Eucalyptus oil	Pain and inflammatory reactions after total knee arthroplasty.	[ 148 ]
36	Bergamot essential oil and synthetic oil	Alleviates the work-related stress of teachers with varying workloads and had a weak effect on young teachers exposed to heavy workloads.	[ 149 ]
37	Peppermint oil	Relaxation of the smooth muscles of the bronchi, increased ventilation and oxygen concentration in the brain and reduced lactate levels in the blood.	[ 138 ]
38	Basil, bergamot, cardamom, cinnamon, juniper, lemon, orange, plasma rosa, peppermint, sandalwood, spearmint and ylang-ylang	Essential oils can have diverse psychophysiological effects.	[ 150 ]