Decoded: How smell of lavender helps you unwind

Scientists have discovered that the fragrant flower lavender is relaxing and may help people unwind and could even be a safer alternative to anti-anxiety drugs.

The study, over mice, showed that the vaporised lavender compound linalool must be smelt -- not absorbed in the lungs -- to feel its calming effects, which could be used to relieve preoperative stress and anxiety disorders.

Mice show less signs of anxiety when they smell the fragrant flower.

"In folk medicine, it has long been believed that odorous compounds derived from plant extracts can relieve anxiety," said co-author Hideki Kashiwadani of Kagoshima University in Japan.

The fragrant flower can also act as an alternative to current anxiolytic (anxiety-relieving) drugs like benzodiazepines, which is known to cause memory problems, male breast growth and birth defects.

In the study, published in Frontiers in Behavioral Neuroscience, the researchers tested mice to see whether it is the smell of linalool -- i.e. stimulation of olfactory (odour-sensitive) neurons in the nose -- that triggers relaxation.

They found that linalool odour has an anxiolytic effect in normal mice. However, this did not impair their movement. 

This contrasts with benzodiazepines, and linalool injections, whose effects on movement are similar to those of alcohol.

"The results suggest that linalool does not act directly on GABAA receptors like benzodiazepines do but must activate them via olfactory neurons in the nose in order to produce its relaxing effects," Kashiwadani explained.

"Our study also opens the possibility that relaxation seen in mice fed or injected with linalool could in fact be due to the smell of the compound emitted in their exhaled breath."

Lavender could also be used pre-surgery or by those who struggle to take drugs, the team said.