Stressed out? Sniff lemon or lavender.

Scientists in Japan have found that inhaling certain fragrances like that of lavender or lemon alter gene activity and blood chemistry such that stress levels are reduced.

The secret ingredient is linalool, a chemical found in flowers and citrus fruits. However, its exact effects on the body are a mystery.

In a new study published in the Journal Of Agricultural And Food Chemistry, Dr Akio Nakamura and his colleagues discovered that lab rats placed under duress had their stress alleviated when they inhaled linalool, ScienceDaily reported.

The researchers noted that people have inhaled the scent of certain plants since ancient times to help reduce stress, fight inflammation and depression and induce sleep.

The researchers found that when they exposed lab rats to stressful conditions, those inhaling linalool had elevated levels of neutrophils and lymphocytes - key parts of the immune system - return to near-normal levels.

Inhaling linalool also reduced the activity of over 100 genes active in stressful situations.

This article was first published in Mind Your Body, The Straits Times.