Elderly Suffer Health Problems From Declining Taste And Smell

October 21, 1997

DURHAM, N.C. -- Elderly people often lose so much of their ability to taste and smell that they could risk serious health consequences as a result of poor nutrition and the loss of sensory pleasure from food, according to a review article in the Journal of the American Medical Association (JAMA).

Duke psychologist Susan Schiffman, author of the Oct. 22 article that reviewed 30 years of scientific literature on the subject, said the decline in taste and smell can be severe enough to put elderly people at risk for malnutrition, lowered immunity to disease, accidental poisonings, and chronic diseases like hypertension and diabetes.

The problem is common: more than three-fourths of people over 80 have major difficulty identifying and perceiving odor, Schiffman said, and the losses can be dramatic. Compared to younger people, elderly people taking an average of three medications required two to 15 times more of an odor or taste before they could detect it.

Although some sensory loss is normal with age, Schiffman said taste loss in particular is considerably worsened by certain medications, surgical procedures and disease processes.

"Deficits in taste and smell not only reduce pleasure and comfort from food, but they can alter the types and amounts of food eaten and can actually reduce the levels of key immune system cells, like T-cells and B-cells," Schiffman said.

While taste and smell have long been known to regulate mood and well-being, Schiffman's own research published in more than a dozen peer-reviewed journals over the years was among the first to prove that taste and smell have a direct link to mental and physical health, not just a related effect through pathways that regulate mood.

The dangers of "chemosensory" deprivation are numerous, Schiffman said. Deficits in sweet taste perception make elderly people with diabetes more vulnerable to the adverse effects of excess sugar, while loss of salt perception can cause hypertensive patients to inadvertently eat too much salt. Loss of salt perception is the biggest taste deficit for elderly people taking medications; compared to younger people, they required as much as 12 times the amount of salt in order to taste it, making older people at greater risk for stroke and high blood pressure.

Even in healthy people, sensory loss can be troublesome. Such difficulties can lead to food poisoning or exposure to hazardous chemicals that would normally be detected by taste and smell.

Without taste and smell, elderly people are unable to select appropriate foods and portion sizes, and they eventually lose the primary reinforcement to eat -- the pleasure derived from tasting and smelling food, Schiffman said. That pleasure takes on particular importance in elderly people for whom other sources of gratification, such as work, family and hobbies, may be limited.

"The loss of pleasure in food can result in malnutrition, especially among people in nursing homes who no longer have control over their food choices and are eating new and unfamiliar foods," Schiffman said. "Malnutrition, in turn, can cause further chemosensory losses by impairing the reproduction of taste cells in the taste buds."

Taste buds are oval-shaped structures on the tongue and palate that consist of up to 100 specialized cells arranged somewhat like segments of an orange. Taste cells constantly reproduce themselves, with a lifespan of approximately 10 days, a renewal process that can be hampered by malnutrition.

Finally, taste and smell are important because they prepare the body to digest food by triggering secretions from the pancreas, intestines, stomach and salivary glands.

While few, if any, treatments exist to restore taste and smell, Schiffman has found that enhancing foods with flavored powders can significantly increase the flavor and enjoyment of the meal. Moreover, her study of patients who ate foods enhanced with powdered flavors like beef, bacon and cheese showed they had significantly higher levels of B-cells and T-cells than when they ate the same foods without enhancers. While the patients ate more of the flavor enhanced foods, nutrition alone did not account for the increased immune status.

Schiffman theorizes that flavors and odors trigger nerve pathways leading to the brain's limbic system, which in turn regulates such diverse functions as mood, productivity and immunity.

Duke University Medical Center

Related Nutrition Articles from Brightsurf:

Here's how to improve packaged foods nutrition
FOP nutrition labeling results in a significant improvement in the nutritional quality of food products.

'Front of package' nutrition labels improved nutrition quality
A new study analyzing 16 years of data on tens of thousands of products finds that the adoption of nutrition data on ''front of package'' labels is associated with improved nutritional content of those foods and their competitors.

Aquaculture's role in nutrition in the COVID-19 era
A new paper from American University examines the economics of an aquaculture industry of the future that is simultaneously environmentally sustainable and nutritious for the nearly 1 billion people worldwide who depend on it.

Fathers are more likely to be referred for nutrition or exercise counseling
Fatherhood status has been linked to medical providers' weight-related practices or counseling referrals.

Refugee children get better health, nutrition via e-vouchers
Electronic food vouchers provided young Rohingya children in Bangladeshi refugee camps with better health and nutrition than direct food assistance, according to new research led by Cornell University, in conjunction with the International Food Policy Research Institute.

Leaders call for 'Moonshot' on nutrition research
Leading nutrition and food policy experts outline a bold case for strengthening federal nutrition research in a live interactive session as part of NUTRITION 2020 LIVE ONLINE, a virtual conference hosted by the American Society for Nutrition (ASN).

Featured research from NUTRITION 2020 LIVE ONLINE
Press materials are now available for NUTRITION 2020 LIVE ONLINE, a dynamic virtual event showcasing new research findings and timely discussions on food and nutrition.

Diet, nutrition have profound effects on gut microbiome
A new literature review from scientists at George Washington University and the National Institute of Standards and Technology suggests that nutrition and diet have a profound impact on the microbial composition of the gut.

Are women getting adequate nutrition during preconception and pregnancy?
In a Maternal & Child Nutrition analysis of published studies on the dietary habits of women who were trying to conceive or were pregnant, most studies indicated that women do not meet nutritional recommendations for vegetable, cereal grain, or folate intake.

Supermarkets and child nutrition in Africa
Hunger and undernutrition are widespread problems in Africa. At the same time, overweight, obesity, and related chronic diseases are also on the rise.

Read More: Nutrition News and Nutrition Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.