The perennial stress-buster – a deep breath – could become
stress-detector, claims a team of researchers from the UK.
According to a new pilot study, published in IOP Publishing's Journal of Breath Research,
there are six markers in the breath that could be candidates for use as
indicators of stress.
The researchers hope that findings such as these could lead
to a quick, simple and non-invasive test for measuring stress; however, the
study, which involved just 22 subjects, would need to be scaled-up to include
more people, over a wider range of ages and in more "normal"
settings, before any concrete conclusions can be made, they state.
Lead-author of the study, Professor Paul Thomas, said:
"If we can measure stress objectively in a non-invasive way, then it may
benefit patients and vulnerable people in long-term care who find it difficult
to disclose stress responses to their carers, such as those suffering from
How the study was
The study, undertaken by researchers at Loughborough University
and Imperial College London, involved 22 young adults (10 male and 12 female)
who each took part in two sessions: in the first, they were asked to sit
comfortably and listen to non-stressful music; in the second, they were asked
to perform a common mental arithmetic test that has been designed to induce
A breath test was taken before and after each session,
whilst heart-rates and blood pressures were recorded throughout. The breath
samples were examined using a technique known as gas chromatography-mass
spectrometry, and then statistically analysed and compared to a library of
Two compounds in the breath – 2-methyl, pentadecane and
indole – increased following the stress exercise which, if confirmed, the
researchers believe could form the basis of a rapid test.
A further four compounds were shown to decrease with stress,
which could be due to changes in breathing patterns.
"What is clear from this study is that we were not able
to discount stress. It seems sensible and prudent to test this work with more
people over a range of ages in more normal settings.
"We will need to think carefully about experimental
design in order to explore this potential relationship further as there are
ethical issues to consider when deliberately placing volunteers under stress.
Any follow up study would need to be led by experts in stress," Professor
Breath profiling has become an attractive diagnostic method
for clinicians, and recently researchers have found biomarkers associated with tuberculosis,
multiple cancers, pulmonary disease and asthma. It is still unclear how to best
manage external factors, such as diet, environment and exercise, which can
affect a person's breath sample.
"It is possible that stress markers in the breath could
mask or confound other key compounds that are used to diagnose a certain
disease or condition, so it is important that these are accounted for,"
said Professor Thomas.
The researcher's initial assumptions are that stressed
people breathe faster and have increased pulse rates and an elevated
blood-pressure, which is likely to change their breath profile. They emphasise,
however, that it is too soon to postulate the biological origins and the roles
of the compounds as part of a stress-sensitive response.