What a scent sets in motion in the mind

How essential oils work, and what research knows about rosemary, lavender and sweet orange

A hint of rosemary in the morning, and the head becomes clearer. Lavender in the evening, and the shoulders drop. Many people know these moments from their own experience.

But what actually happens in the body? Research now has some fascinating answers.

Small molecules, big effect

Essential oils consist of tiny, fat-soluble molecules. When inhaled, they reach the olfactory system within seconds. From there the signals go directly to the limbic system, which processes feelings and memories.

A small part of the aromatic molecules also enters the bloodstream via the lungs. So they work in two ways. Alongside their authentic, natural scent, we can benefit from their fascinating properties, always provided we are not working with synthetic substances, because then the effects are not particularly beneficial.

What the laboratory shows

In laboratory tests, many essential oils show remarkable properties:

• Antioxidant. Lemon and rosemary contain substances that capture free radicals.
• Antimicrobial. Tea tree, thyme and lavender slow the growth of bacteria and fungi in the test tube.
• Inflammation-modulating. Components of chamomile, immortelle or ginger intervene in inflammatory processes in laboratory tests.

What happens in a test tube, however, cannot be transferred one to one to people. We therefore use essential oils for wellbeing and focus on studies that observe people under the influence of scent.

A word about frankincense

Frankincense is often associated with boswellic acids, which are credited with anti-inflammatory properties. Frankincense is therefore very much in vogue right now, and with some justification. But these acids are found in the resin and in resin extracts, not in the essential oil. They are too heavy to rise with the steam during distillation.

Essential frankincense oil consists mainly of light aromatic molecules such as alpha-pinene and limonene. We value it for its warm, resinous scent and its grounding effect in a room.

Rosemary: a fresh kick for the brain

Rosemary oil contains a lot of 1,8-cineole. A study at Northumbria University showed that people who worked in a room scented with rosemary had cineole in their blood afterwards. And the higher the level, the faster and more accurately the participants solved arithmetic tasks.

The researchers suspect that cineole slows down an enzyme that breaks down the messenger acetylcholine. Acetylcholine is important for attention and memory.

In addition, rosemary stimulates the limbic system and the hypothalamus via the sense of smell. This awakens mental alertness, and the body switches into «ready» mode.

Rosemary oil thus acts like a natural fresh kick for the brain, ideal when studying, doing creative work or before an important meeting.

Peppermint is a similar wake-up call. In a study with 144 participants, people remembered more and felt more attentive in a peppermint scent than without any scent.

Lavender: coming to rest

Lavender is the classic for relaxation. Its main components, linalool and linalyl acetate, act on the nervous system. Among other things, they influence the GABA system, which is responsible for calming.

In a Viennese study, 200 people waited in a dental practice. Those who smelled lavender or orange were less anxious and in a better mood than the comparison group.

Lavender is therefore a lovely companion for the evening ritual and for switching off after a long day.

Sweet orange: lightness in the room

Sweet orange (Citrus sinensis) consists largely of limonene. Its scent is considered warm and uplifting.

An earlier study from Vienna already showed that women who smelled orange in the waiting room were calmer and in a better mood.

Limonene acts via the sense of smell directly on the limbic system, our emotional centre. Researchers are investigating how citrus scents influence serotonin and dopamine. Serotonin is considered the feel-good messenger, dopamine stands for motivation and drive.

No wonder, then, that for many people orange smells of sunshine. Of joie de vivre and energy in everyday life. That is why it fits so well in reception areas, breakfast rooms and anywhere lightness is called for.

From knowledge to blend

Every oil brings its own chemistry. That is exactly what makes working with them so exciting.

At Casa Cafaro we therefore do not compose our blends by scent alone. We also ask: what should a room bring about? Wake people up, calm them, welcome them?

Because a good scent does not just smell beautiful. It suits what a person needs right now.

Frequently asked questions

Which scent suits which room? Fresh citrus notes such as sweet orange bid welcome at reception. Rosemary and peppermint suit meeting rooms and work areas. A good concept thinks room by room. Often it takes a blend to achieve ideal results.

Can scent in the office support concentration? Studies with rosemary and peppermint show that people worked more attentively and remembered more in the scent. A subtly scented meeting room can therefore make meetings noticeably more productive.

Why do you stop noticing a scent after a while? The nose gets used to constant smells and filters them out. That is why we scent with pauses. This way people perceive the scent afresh every time they enter a room.

Sources

1. Moss M, Oliver L (2012). Plasma 1,8-cineole correlates with cognitive performance following exposure to rosemary essential oil aroma. Ther Adv Psychopharmacol 2(3):103–113. doi.org/10.1177/2045125312436573
2. Lehrner J et al. (2005). Ambient odors of orange and lavender reduce anxiety and improve mood in a dental office. Physiol Behav 86:92–95. doi.org/10.1016/j.physbeh.2005.06.031
3. Lehrner J et al. (2000). Ambient odor of orange in a dental office reduces anxiety and improves mood in female patients. Physiol Behav 71:83–86. doi.org/10.1016/s0031-9384(00)00308-5
4. Tisserand Institute. Does Frankincense oil contain boswellic acid? tisserandinstitute.org
5. Moss M et al. (2008). Modulation of cognitive performance and mood by aromas of peppermint and ylang-ylang. Int J Neurosci 118(1):59–77. doi.org/10.1080/00207450601042094