A rosemary plant on your desk could improve your work performance and how you feel about it. The old saying "rosemary is for remembrance" seems true. Smelling the herb produces beta brain waves which demonstrate alertness.
The link between smelling rosemary and scoring higher on mental tests was established by Dr Moss in 2003. However, more surprising news was to come. The more of the compound in the bloodstream the more cognitive performance was improved.
Several studies demonstrate that the smell of lemons can reduce stress at least in rodents.
In one investigation the technical research centre at the Japanese flavour and fragrance company T Hasegawa gave stressed lab rats linalool, a component of lemons.
The researchers say their findings could form the basis of new blood tests for identifying stress-busting fragrances. At the Institute of Pharmacology in Tübingen, Germany, mice that became active after exposure to oils of rosemary and dwarf pine calmed down with oils of lemon balm and valerian.
The sweet white flowers could be nature's Valium. Researchers at Ruhr University led by Prof Hatt found that brains can respond as well to jasmine as to sedatives and barbiturates.
Tests showed jasmine dramatically calmed mice when their cage was filled with it. Brain scans confirmed this. By changing the chemical structure of the scent molecules researchers hope to achieve even stronger effects. Jasmine soothes, promotes high quality sleep and relieves anxiety.
Dr Hirsh says jasmine also helps to improve hand-eye coordination in cases as diverse as classical violinists and doctors performing micro-neurosurgery.
Getting pumped up with peppermint may improve workouts and accuracy in the workplace.
Dr Bryan Raudenbush at Wheeling Jesuit University, West Virginia, found that athletes who sniffed peppermint during exercise ran faster, had greater grip strength and could do more push-ups than those who did not.He says peppermint and cinnamon both fight driving fatigue.
In 2000 researchers at the University of Vienna's Neurological Clinic examined the response to orange scent in a dentist's waiting room. The odour had a relaxing effect, mostly on women. Compared to patients not exposed to the scent they had lower anxiety, felt more positive and were calmer.
Violent criminals in Rotterdam in the Netherlands became less aggressive and had fewer fights when exposed to the scent of oranges, according to a 2008 study.
Sniffing green apples may control blood pressure, lessen migraine pain and help you lose weight. Dr Gary E Schwartz, professor of psychology, medicine, neurology, psychiatry and surgery at the University of Arizona, found that in particular the smell of spiced apples can control blood pressure as well as meditation.
Apples may also reduce migraine pain. In the knowledge that research suggested some smells can trigger migraine Dr Hirsch theorised the opposite could also be true. He investigated the effects of green apples since previous studies had pointed to their ability to reduce anxiety. Many patients had less pain but only if they liked the smell.
In one of Dr Hirsch's experiments three quarters of claustrophobic volunteers felt better about being in a lift after smelling cucumber. Some hospitals apply cucumber oil on a cotton square and put it under a patient's nose while they have MRI scans.
Lavender pillows may help you sleep. Dr Mark Moss of Newcastle's Northumbria University found that lavender has a consistent sedative effect. It slows reactions, reduces attention and impairs working memory, the part of the brain that puts facts on hold before storing them.
Lavender may also help the elderly avoid falls and be less agitated. Researchers at the Department of Internal Medicine and Rehabilitation Science at Tohoku University recently did three trials on lavender in randomly selected nursing homes in northern Japan.
Those who smelled the lavender had significantly fewer falls and were calmer. Researchers speculate that lavender has a stabilising effect on balance.