Anybody with knowledge of aromatherapy knows that lavender is a sleep aid. The problem is that lavender's sleep aiding properties were until now based purely on anecdotal evidence.
"Unfortunately, anecdotal evidence carries an opportunistic bias that accentuates the positive and neglects the negative. Our new research does now contain such a bias and thus validates the claim," said head researcher of the university study Namni Goel.
The study - supported by the Sense of Smell Institute - found that lavender increased the amount of time subjects spent in slow wave or deep sleep - the restful, restorative phase of sleep - resulting in higher vigor scores on the Profile of Mood States test.
While lavender improved sleep for both men and women, it was found to work better for females. The study suggests that this better sleep ability may be due to the effects of reproductive hormones in women.
Research also showed that women in general are better sleepers than men, with females found to sleep longer, have greater sleep efficiency, and take less time to fall asleep.
"In addition to helping healthy people, lavender may benefit depressed people who characteristically show a reduction of deep sleep time. Indeed, the study has demonstrated an increased sensitivity to lavender in depressed young adults," said Goel.
Habitually poor or irregular sleepers including the elderly are thought to benefit from smelling lavender fragrances last thing in the evening.