Why bad smells in the house, such as the kitchen trash and sweaty sports bags, can be a sign that you are stressed
The trash stinks, the fridge stinks, and the smell of sweaty gym gear is overpowering… but relax.
The house may not need cleaning yet, maybe you’re just a little stressed.
A study has found that our sense of smell for unpleasant odors is heightened when we are tense.
But our sensitivity to pleasant or neutral smells is unchanged.
It is thought that the release of the ‘stress hormone’ cortisol, when we are in ‘fight or flight’ mode, allows us to better detect bad smells that may pose a threat.
It is thought that the release of the ‘stress hormone’ cortisol, when we are in ‘fight or flight’ mode, allows us to better detect bad smells that may pose a threat. (File image)
Researchers asked 40 men and women to take a stressful speaking activity and math test, then measure how well they could detect pleasant, neutral and unpleasant odors.
The pleasant scent was citronellol, which smells like lemongrass and rose, while the neutral scent was 2-heptanol, which was described as “earthy, oily.” The unpleasant odor was 4-methylpentanoic acid, which smells like sweat socks.
Sensitivity to unpleasant odors
The participants were also asked to come to the lab a week before or a week later for a control session, during which they performed the same odor detection tests, but without participating in the stress-inducing tasks beforehand.
The researchers from Southwestern University in China said: ‘There was a significant effect of stress on odor sensitivity to the unpleasant odor. However, there was no significant effect of stress on sensitivity to pleasant or neutral odors.’
A study has found that our sense of smell for unpleasant odors is heightened when we are tense
The group added, “A state of hypervigilance after exposure to acute psychological stress may increase the sensitivity of the olfactory system to detection of potentially threatening stimuli, which is influenced by stress-related cortisol reactivity.”
The study’s findings have been published in the journal Hormones and Behavior.
Dr. Andrew Thomas, a psychologist and lecturer at Swansea University who was not involved in the study, said: ‘From an evolutionary perspective, these results make sense.
Cortisol is a stress hormone released when the body responds to threats as part of the flight or fight response.
“Fight or flight, and freezing, have numerous effects on the body to prepare it for threats.
‘If we assume that what these researchers found applies to larger samples, then it suggests that the stress response also increases our sensitivity to unpleasant odors.
“The odors we find unpleasant are usually odors that indicate the presence of something harmful, such as bacterial growth.”