Essential oils: what actually happens?

Smell, memory and the cool feeling of menthol, explained with the research.

Turban Sauna // Journal

In a SaunaGus, the gusmaster mixes essential oils into the water that goes on the hot stones. The steam carries the oils through the room, and within seconds you sense them in your nose, on your skin and in your breath. Here is what happens in the body, and how far the research reaches.

Smell takes the short way to the brain

Scent molecules bind to receptors high up in the nose. From there, the signal goes to the olfactory bulb, which is directly connected to the parts of the brain that handle emotion and memory. The other senses pass through a relay station first. This is why a smell can bring back a memory or a mood before you have put a word to it.

Menthol and eucalyptus feel cold

In 2002, researchers in California discovered the receptor that senses cold in the skin and mucous membranes. It is called TRPM8, and it reacts both to falling temperature and to menthol. Eucalyptol, the main compound in eucalyptus oil, activates the same receptor. That is why peppermint and eucalyptus feel cool on the skin and in the throat in a room at 80 to 90 degrees. The temperature stays the same. The nerves send a cold signal.

Menthol also gives a feeling of freer breathing. A review of the research shows that the airway itself stays the same width. The cold nerves in the nose report more airflow, and the brain experiences each breath as easier.

What research shows about mood

A systematic review of aromatherapy studies found credible evidence that scents affect mood, physiology and behaviour. The same review found that expectation, earlier experience and culture explain the effects better than a direct chemical action of each oil. How you feel about a scent matters as much as the scent itself.

Claims that a specific oil treats a specific condition rest on weak evidence. Many studies are small, and it is hard to test a scent blind. We use essential oils for what they reliably do: sharpen the senses and give each round its own character.

Essential oils at TURBAN

The gusmaster dilutes a few drops of oil in water and pours it on the stones, so the oils reach you as steam. If you have asthma, are sensitive to scents or are pregnant, sit on a lower bench and tell the gusmaster before the round, and read our safety information.

Sources

McKemy et al. (2002): Identification of a cold receptor reveals a general role for TRP channels in thermosensation

Eccles (1994): Menthol and related cooling compounds

Herz (2009): Aromatherapy facts and fictions