Prevalence of phantom
odor perception
NIH/National Institute
on Deafness and Other Communication Disorders
Imagine the foul smell
of an ash tray or burning hair. Now imagine if these kinds of smells were
present in your life, but without a source.
A new study finds that
1 in 15 Americans (or 6.5 percent) over the age of 40 experiences phantom
odors.
The study, published
in JAMA Otolaryngology-Head and Neck Surgery, is the first in the
U.S. to use nationally representative data to examine the prevalence of and
risk factors for phantom odor perception. The study could inform future
research aiming to unlock the mysteries of phantom odors.
The study was led by Kathleen Bainbridge, Ph.D., of the Epidemiology and Biostatistics Program at the National Institute on Deafness and Other Communication Disorders (NIDCD), part of the National Institutes of Health. Bainbridge and her team used data from 7,417 participants over 40 years of age from the 2011-2014 National Health and Nutrition Examination Survey (NHANES).
The NHANES data were
collected by the National Center for Health Statistics, which is part of the
Centers for Disease Control and Prevention; data collection was partly funded
by the NIDCD.
"Problems with
the sense of smell are often overlooked, despite their importance. They can
have a big impact on appetite, food preferences, and the ability to smell
danger signals such as fire, gas leaks, and spoiled food," said Judith A.
Cooper, Ph.D., acting director of the NIDCD.
Donald Leopold, M.D.,
one of the study's authors and clinical professor in the Department of Surgery
at University of Vermont Medical Center, Burlington, adds that patients who
perceive strong phantom odors often have a miserable quality of life, and
sometimes cannot maintain a healthy weight.
Researchers used this
NHANES survey question to determine whether participants had experienced
phantom odor perception: "Do you sometimes smell an unpleasant, bad, or
burning odor when nothing is there?"
To explore the
correlation between phantom odors and participant characteristics, the
researchers looked at participants' age, sex, education level, race/ethnicity,
socio-economic status, certain health habits, and general health status.
The ability to
identify odors tends to decrease with age. Phantom odor perception, on the
other hand, seems to improve with age.
One previous study,
using data from a community in Sweden, showed that 4.9 percent of people over
the age of 60 experience phantom odors, with a higher prevalence in women than
men.
The present study
found a similar prevalence in the over-60 age group, but in examining a broader
age range, found an even higher prevalence in ages 40-60.
The study also found
that about twice as many women as men reported phantom odors, and that the
female predominance was particularly striking for those under age 60.
Other risk factors for
the onset of phantom odors include head injury, dry mouth, poor overall health,
and low socio-economic status.
Researchers
hypothesized that people with lower socio-economic status may more commonly be
exposed to environmental pollutants and toxins, or have health conditions that
contribute to phantom odors, either directly or because of medications needed
to treat their health conditions.
"The causes of
phantom odor perception are not understood. The condition could be related to
overactive odor sensing cells in the nasal cavity or perhaps a malfunction in
the part of the brain that understands odor signals. A good first step in
understanding any medical condition is a clear description of the phenomenon.
From there, other researchers may form ideas about where to look further for
possible causes and ultimately for ways to prevent or treat the
condition," said Bainbridge.
