How aromatherapy works? Lavender, basil, oranges etc de-stress

Scientists in Japan found what they say is the first scientific evidence that inhaling certain fragrances alter gene activity and blood chemistry in ways that can reduce stress levels.

The magic ingredient is linalool, found in various fruits and flowers like mango, lavender, tea, grape, tomato, basil, citrus fruit like oranges and lemons, and some other fragrant plants.

"Linalool returned stress-elevated levels of neutrophils and lymphocytes — key parts of the immune system — to near-normal levels."

Stress Repression in Restrained Rats by (R)-(–)-Linalool Inhalation and Gene Expression Profiling of Their Whole Blood Cells, Akio Nakamura and colleagues, July 2009.

Note the experiments involved rats rather than people.

Also reported by the BBC.