Approximately 23 percent of U.S. adults ages 40 and older report having had a problem with their ability to smell, and about 19 percent report having had a problem with their ability to taste, according to a recently published study. Conducted by the National Institute on Deafness and Other Communication Disorders (NIDCD), part of the National Institutes of Health (NIH), and the National Center for Health Statistics (NCHS), part of the Centers for Disease Control and Prevention (CDC), the study examines the first collection of nationally representative, population-based survey data of middle-aged and older adults on perceived smell and taste problems, related risk factors, and treatments.
Published online October 20, 2015, in the journal Chemical Senses, the study confirms earlier findings that problems with the perception of smell or taste—also known as chemosensory disorders—increase with age. Nearly one in three (31 percent) adults 80 years and older say they have experienced a problem with their sense of smell, including a diminished sense of smell over time. More than one in four (27 percent) adults 80 years and older report having had a problem with their sense of taste, including changes in taste sensation over time.
Chemosensory disorders can challenge health and well-being through diminished ability to detect environmental hazards and maintain healthy eating. For example, people who have a poor ability to smell or taste may miss important cues such as gas leaks, fire, and spoiled food.
The study is an analysis of data from the 2011–2012 National Health and Nutrition Examination Survey (NHANES), which is conducted by NCHS. More than 3,600 U.S. adults 40 years and older answered a questionnaire about perceived smell and taste problems, chemosensory losses since age 25, related risk factors, and treatment of chemosensory problems. The NIDCD collaborated with NCHS on the development of the survey questions, which were content-validated by chemosensory experts and tested for response problems and cultural appropriateness.
"The data from this survey suggest that self-reported chemosensory problems are an increasing issue among middle-age and older adults," said Howard J. Hoffman, M.A., NIDCD director of epidemiology and statistics and a co-author of the study. "This new NHANES component also allowed us to gather self-reported risk factors for chemosensory disorders, giving us a better understanding of the scope of these issues."
For example, participants who had experienced cold or flu symptoms lasting more than a month or allergy-related nasal congestion in the past year were twice as likely to report having a smell disorder as those who did not report sinonasal symptoms. Other risk factors for smell disorders included heavy drinking, loss of consciousness from a head injury, family income, and dry mouth (xerostomia). Participants with dry mouth were more than twice as likely to also report taste alteration. Other factors affecting the ability to taste included nose or facial injury, lower educational level, and fair or poor health.
Of adults ages 40 and older who reported having a problem with their ability to smell, 6 percent reported they had phantosmia (smelling phantom odors). Of adults ages 40 and older who reported having a problem with their ability to taste, 5 percent reported they had dysgeusia, or distortion of the sense of taste.
As part of national health improvement objectives, Healthy People 2020 recently included chemosensory-related objectives to encourage identification, treatment, and risk management of chemosensory disorders. Beginning in January 2012, NHANES participants also took taste and smell tests, which will add important objective measurements to the data. NHANES is the only nationally representative health survey in the United States that combines in-person interviews with physical examinations.
Future release of NHANES chemosensory exam data will provide prevalence and associated risk factors of measured chemosensory problems.
For more statistics on taste and smell, see the NIDCD’s Statistics on Taste and Smell page.