Summary: A new study reveals 1 in 15 Americans over the age of 40 experience phantom odor perception.
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.
Funding: National Center for Health Statistics, Centers for Disease Control and Prevention, NIH/National Institute on Deafness and Other Communication Disorders funded this study.
Source: NIDCD news – NIH/NIDCD
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Original Research: Abstract for “Factors Associated With Phantom Odor Perception Among US Adults: Findings From the National Health and Nutrition Examination Survey” by Kathleen E. Bainbridge, PhD, MPH; Danita Byrd-Clark, BBA; and Donald Leopold, MD in JAMA Otolaryngology – Head & Neck Surgery Published August 16 2018.
Factors Associated With Phantom Odor Perception Among US Adults: Findings From the National Health and Nutrition Examination Survey
Phantom odor perception can be a debilitating condition. Factors associated with phantom odor perception have not been reported using population-based epidemiologic data.
To estimate the prevalence of phantom odor perception among US adults 40 years and older and identify factors associated with this condition.
Design, Setting, and Participants
In this cross-sectional study with complex sampling design, 7417 adults 40 years and older made up a nationally representative sample from data collected in 2011 through 2014 as part of the National Health and Nutrition Examination Survey.
Sociodemographic characteristics, cigarette and alcohol use, head injury, persistent dry mouth, smell function, and general health status.
Main Outcomes and Measures
Phantom odor perception ascertained as report of unpleasant, bad, or burning odor when no actual odor exists.
Of the 7417 participants in the study, 52.8% (3862) were women, the mean (SD) age was 58 (12) years, and the prevalence of phantom odor perception occurred in 534 participants, which was 6.5% of the population (95% CI, 5.7%-7.5%). Phantom odor prevalence varied considerably by age and sex. Women 60 years and older reported phantom odors less commonly (7.5% [n = 935] and 5.5% [n = 937] among women aged 60-69 years and 70 years and older, respectively) than younger women (9.6% [n = 1028] and 10.1% [n = 962] among those aged 40-49 years and 50-59 years, respectively). The prevalence among men varied from 2.5% (n = 846) among men 70 years and older to 5.3% (n = 913) among men 60 to 69 years old. Phantom odor perception was 60% (n = 1602) to 65% (n = 2521) more likely among those with an income-to-poverty ratio of less than 3 compared with those in the highest income-to-poverty ratio group (odds ratio [OR], 1.65; 95% CI, 1.06-2.56; and OR, 1.60; 95% CI, 1.01-2.54 for income-to-poverty ratio <1.5 and 1.5-2.9, respectively). Health conditions associated with phantom odor perception included persistent dry mouth (OR, 3.03; 95% CI, 2.17-4.24) and history of head injury (OR, 1.74; 95% CI, 1.20-2.51).
Conclusions and Relevance
An age-related decline in the prevalence of phantom odor perception is observed in women but not in men. Only 11% (n = 64) of people who report phantom odor perception have discussed a taste or smell problem with a clinician. Associations of phantom odor perception with poorer health and persistent dry mouth point to medication use as a potential explanation. Prevention of serious head injuries could have the added benefit of reducing phantom odor perception.