Unlike problems in vision and hearing, age-related losses to smell and taste have only recently gained attention. Like declines in the other senses, losing the ability to smell different odors and scents and to taste food can lead to serious quality-of-life and safety issues.
When the sense of smell or taste diminishes, the world becomes a different place. Adults who have trouble smelling and tasting often have poor appetites, which can lead to weight loss, malnutrition and weakened immune systems. Losing the ability to enjoy food can also contribute to emotional problems such as anxiety and depression.
Research shows that often people who complain that they can’t taste food are actually experiencing a loss in their sense of smell. To compensate for the loss of taste, people may add too much salt or sugar to their foods, which can hamper the treatment of common chronic diseases like heart disease, hypertension and diabetes that require sticking to a specific diet.
One study showed that those with taste problems required three times as much salt to detect it in tomato soup. As a result, adults with smell and taste issues may eat too much and gain weight, or eat too little and lose weight. Some, particularly the very old, may stop eating altogether.
In addition to being a quality-of-life issue in itself, smell and taste losses also can be signs of serious neurological diseases affecting older adults, such as Parkinson’s and Alzheimer’s.
Journalists covering this issue should know that in addition to hurting older adults’ quality of life, smell and taste losses could lead to important safety issues for both the individuals and for the public.
The National Health and Nutrition Examination Survey, or NHANES, which studies the health and nutritional status of adults and children in the United States, adopted smell and taste testing in January 2013. They will release updated data in 2015 on the prevalence and impact of the loss of taste and smell in the entire U.S. population.
Health effects
According to an NIH fact sheet, older adults with total or partial smell losses are almost twice as likely to have cooking accidents – or may eat or drink spoiled foods or toxic substances.
Additionally, loss of the ability to smell may lead to even more serious adverse events such as the ability to detect the odor of dangerous fumes like smoke from a fire or leaking gas.
Specific disorders
- hyposmia, a reduced ability to detect certain odors;
- dysosmia, in which pleasant odors smell bad and vice versa;
- anosmia, an inability to detect any odors; and
- presbyosmia, which is smell loss due to aging.
Taste disorders include:
- hypogeusia, a reduced ability to taste – sweet, sour, bitter, salty and savory—common in older adults and the elderly;
- dysgeusia, when flavors are distorted; and
- ageusia, an inability to taste at all.
Smell and taste disorders have similar causes, including certain medications, infections, head injuries and dental problems. Age-related changes in the cells in the nose and mouth also lead to smell and taste losses.
Physicians diagnose smell and taste disorders through a variety of tests. The smell tests measure the amount of odor patients can detect and how accurately they can identify them. Similarly, taste tests measure patients’ responses to different substances. They include a “sip, spit and rinse” test; substances also may also be applied directly to patients’ tongues.
A challenge in older adults is that they may take multiple drugs for different illnesses and many of those medications – for hypertension, for hormone therapy and for depression – inhibit taste and smell. Physicians have to sort out the effect of these drugs on smell and taste in older adults.
While some smell and taste disorders can be eased by reducing or eliminating certain medications or by treating the underlying condition such as a sinus infection, smell and taste losses due to aging are not currently preventable. Instead, physicians and other health professionals suggest strategies to adjust to and manage these conditions.
For example, to enhance the flavors of food, use a variety of spices or add flavorings to soups and vegetables. Also:
- Lemon can boost the flow of saliva, which is important in tasting;
- Marinades for chicken, beef and fish can intensify the aromas;
- A variety of foods and textures and food temperatures on the plate can make the meal more appealing
Prevention
To make sure the older adults aren’t eating spoiled foods and beverages, family members, neighbors and friends should include an examination of an older person’s food in their wellness checks.
To curb or prevent potential safety problems, visual gas detection devices can be purchased for those with gas stoves. Smoke and carbon monoxide detectors should be installed throughout a home, apartment or residences for older adults.
In addition, researchers with NIH’s National Institute on Deafness and Other Communications Disorders, or NIDCD, are exploring how age-related losses in smell and taste can be prevented. They are also exploring associations between smell disorders and changes in diet and food preferences in the elderly.
Several institutions are studying smell and taste disorders, including the University of Pennsylvania Smell and Taste Center and the Taste and Smell Clinic at the Center for Molecular Nutrition and Sensory Disorders in Washington, D.C.
Stats and facts:
- According to the National Institute on Aging, 15 million, or slightly more than 24 percent, of Americans aged 55 and older have a problem with their sense of smell.
- Of that group, 30 percent of Americans between the ages of 70 and 80, and almost a third of people over the age of 80, have a problem with their sense of smell.
- Trouble with the sense of smell is more common in men than in women.
- Although people start out with 10,000 taste buds on the back, side and tip of the tongue, by age 50, you start losing them.
- Smell losses are common in people with dementia.
- In a much-cited study of about 2,500 residents aged 53 to 97 in Beaver Dam, Wis., almost a quarter, or 24.5 percent, had some degree of smell losses. The impairments were greater among men and increased with age, with almost 63 percent of the persons aged 80 to 97 with impaired senses of smell.
- According to NIH’s NIDCD, more than 200,000 people a year visit a physician for problems with taste or smell.
Websites and links:
NIA’s Problems with Sense of Smell in the Elderly
NIA’s Loss of Taste in the Elderly
NIH Senior Health: Problems With Smell
NIH Senior Health: Problems With Taste
American Family Physician: Smell and Taste Disorders: A Primary Care Approach. Good overview from primary care physician’s perspective.
Study on the Effects of Aging on Smell and Taste. Good overview.
National Institute of Health’s National Institute on Deafness and Other Communication Disorders
NIDCD’s Taste and Smell Charts and Tables
What the Numbers Mean: An Epidemiological Perspective on Taste and Smell
Media-friendly sources
Alan Hirsch, M.D., F.A.C.P., director, Smell and Taste Treatment and Research Foundation, Chicago, Ill. Foundation phone: 312-649-5829. E-mail: dr.hirsch@smellandtaste.org
Any research and extension agent in most counties in the United States
Dietitians in the state chapters of the American Dietetics Association
Story ideas
- Choose an assisted-living facility in your community and find out how they enhance foods for their residents and meet their nutritional needs.
- Find a person or persons who did not detect gas, leading to a safety problem, and what they did to avoid it in the future.
- Visit a local senior center and talk to staff and attendees about losing interest in eating because of diminished smell and taste and what they have done about it.
- Are programs like Meals on Wheels and publicly-sponsored family nutrition programs doing anything to address smell and taste issues in older adults?
- Check local cooperative extensions or community colleges for workshops or classes on meal preparation ideas to appeal to those with sensory losses.
- Contact a culinary school and see whether there are courses or programs for chefs that deal specifically with these issues, or talk to a few local chefs to learn how, or if, they address this issue.
Barbara Bein recently covered medical education for the American Academy of Family Physicians in Leawood, Kan.
