Are you an asthmatic and constantly worried about scents and fragrances in the surrounding air? This thought alone can actually harm you more than you can think of.
A new research reveals that simply believing that an odour is potentially harmful can increase airway inflammation in asthmatics for at least 24 hours following exposure.
"Asthmatics often are anxious about scents and fragrances. When we expect that an odour is harmful, our bodies react as if that odour is indeed harmful," said Cristina Jaen, a physiologist at Monell Chemical Senses Center in Philadelphia.
In the study, 17 moderate asthmatics were exposed to the odour of phenylethyl alcohol (PEA) for 15 minutes. Often described as rose-smelling, PEA is regarded as a "pure" odourant with no associated physiological irritant qualities.
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Eight participants were told that the odour had potential therapeutic properties, while nine were told that it potentially could cause mild respiratory problems.
Individuals who were told that the odour was potentially harmful rated it as more irritating and annoying as compared to those who thought it might be therapeutic.
In addition, airway inflammation increased immediately following odour exposure in subjects who believed the odour might be harmful and remained elevated 24 hours later.
The findings suggest that some fragrance effects on asthma symptoms may be related to the expectation of harm as opposed to chemical properties of the odour.
"It is not just what you smell, but also what you think you smell," Jaen noted in a paper published online in the Journal of Psychosomatic Research.