By: Matthew Wallace
The body’s olfactory and gustatory functions play a vital role in nutrition and food selection, making them crucial for maintaining good quality of life. Both of these chemical sensing processes are interrelated. An impairment of either function interferes with the other sense. Olfactory impairment refers to the loss of smell. Gustatory impairment refers to the loss of taste. People who complain about gustatory loss often have a smell disorder, instead of a taste dysfunction. Losing either sense can significantly reduce the pleasure and comfort acquired from food.
In addition, it can lead to vulnerabilities of environmental hazards that most people can detect. More than 2 million U.S. citizens suffer from smell and taste disorders, with more people suffering from olfactory dysfunction than gustatory impairment. The causes of both disorders vary; however, the majority of them deal with ear, nose, and throat disturbances.
Olfactory Impairment
The pleasant smell of flowers, sweet perfumes, and delicious meals contribute towards our happiness. Many of us take this sensory perception for granted by thinking it could never go away. Unfortunately, this could change with the development of a smell disorder. Smell disorders, or olfactory impairment, can severely impact a person’s health and quality of life. More than 200,000 people see their doctor each year about problems with their sense of smell and taste. Both chemical senses are closely related to each other. In fact, some people who think they have lost their sense of smell actually have a taste disorder.
Key Facts
- Roughly 30 percent of U.S. citizens between the ages of 70 and 80 have problems detecting smells. In addition, 2 out of 3 U.S. citizens over the age of 80 have developed problems with their sense of smell.
- Smell disorders can have a huge impact on the lives of those who have trouble detecting scents and fragrances in their surroundings, such as coffee, roses, rain, and propane.
- Individuals with smell disorders have trouble enjoying their food and beverages, because the sense of smell ties in closely with the sense of taste.
- The sense of smell warns people of dangers in their environment, such as leaking gasoline or propane.
- A loss of smell may be a warning of more serious health conditions.
- People may experience a total or partial loss of smell, depending on the cause.
- Many people believe they have a problem with a loss of taste; however, it may actually be a problem with their sense of smell.
- People who experience loss of taste typically cook less than stellar dishes, eating spoiled foods or toxic substances, and fail to detect gas leaks or house fires.
Causes
- Common causes of olfactory impairment include allergies, nasal and sinus disease, head trauma, cigarette smoking, neurodegenerative disease, respiratory infection, and age.
- Less common causes of olfactory impairment include medications, industrial chemical exposure, nutritional deficiency, toxic chemical exposure, radiation treatment of the head and neck, and congenital conditions.
- Uncommon causes of olfactory impairment include brain tumors, psychiatric conditions, Sjögren’s syndrome, epilepsy, lupus, migraine headaches, and endocrine disorders.
Prevention
- Age-related loss of smell cannot be prevented.
- People typically regain their sense of smell when they stop taking medications.
- Cigarette smokers report an improved sense of smell after quitting.
- Wear a helmet when riding a bicycle or motorcycle to avoid head trauma. In addition, wear a seat belt while driving or riding as a passenger.
- Avoid contact with insecticides and solvents to avoid olfactory impairment. See a doctor immediately after making contact with these chemicals.
- Wash hands frequently to avoid loss of smell due to respiratory infections, especially during the winter months. In addition, avoid allergens to improve sense of smell.
- Visit the doctor each year to get the flu shot to prevent contracting influenza. In addition, talk to a doctor about any medications that may inhibit the sense of smell. Doctors may locate the problem and mitigate unwanted side effects.
- Remove nasal polyps to restore smell.
- Take daily vitamins and minerals to avoid nutritional deficiencies.
Who is at Risk
- Individuals age 60 and older.
- Individuals with severe allergies.
- Individuals with an upper respiratory infection.
- Individuals who experienced severe head trauma.
- Individuals with nasal polyps or sinus cavities.
- Individuals with endocrine disorders.
- Individuals with prolonged exposure to insecticides and other harmful chemicals.
- Individuals taking some medications may experience olfactory impairment.
- Individuals who smoke tobacco or abuse cocaine.
- Individuals who have undergone radiation therapy to the head and neck.
- Individuals with neurodegenerative diseases, such as Alzheimer’s, Parkinson’s, and multiple sclerosis.
- Individuals who have lost their larynx often complain of their loss of smell and taste.
Gustatory Impairment
The taste of sweet beverages, succulent dishes, and delicious baked goods provides one of the greatest aspects of quality life. The loss of taste can have a negative impact on health, resulting in poor food choices, suppressed appetite, and malnutrition. In addition, the loss of smell makes people vulnerable to eating rancid food, because their ability to discern good from bad food has diminished. The loss of taste typically affects the elderly more than any other age group.
Key Facts
- The most common taste disorder is phantom taste perception, or a lingering of an unwanted taste with nothing in the mouth.
- Hypogeusia is a reduced ability to taste sweet, salty, sour, bitter, and umami foods.
- People who do not detect any tastes have a condition called ageusia.
- Very few people have lost their sense of taste completely.
- Most people experience a loss of smell, instead of a loss of taste.
- People with dysgeusia experience a salty, rancid, foul, or metallic taste in their mouth.
- People with dysgeusia may also experience burning mouth syndrome, a condition that presents a burning mouth sensation.
- Burning mouth syndrome commonly occurs in elderly women.
Causes
- Medications
- Respiratory or middle ear infections
- Head injury
- Exposure to unnatural chemicals or medications, such as antihistamines and antibiotics
- Radiation therapy for head and neck cancers.
- Dry mouth
- Cigarette smoking
- Vitamin and mineral deficiencies
- Bell’s palsy
- Sjogren’s syndrome
- Dental problems
- Poor oral hygiene
Prevention
- Wash hands frequently to prevent loss of taste associated with respiratory infections.
- Avoid allergens if the loss of taste persists.
- Visit the doctor for a flu shot to prevent contracting influenza and other serious respiratory infections.
- Quit smoking or chewing tobacco products.
- See the doctor about changing medications. A doctor can identify and mitigate unwanted side effects by writing alternative prescriptions.
Who is at Risk
- Individuals with allergic or vasomotor rhinitis.
- Individuals with nasal polyps.
- Individuals with Adenoid hypertrophy.
- Individuals with a respiratory infection.
- Individuals who experienced head trauma.
- Individuals with a neurodegenerative disease, such as Parkinson’s disease, multiple sclerosis, and Alzheimer’s disease.
- Individuals with vitamin and mineral deficiencies.
- Individuals with brain tumors.
- Individuals with endocrine disorders, such as diabetes mellitus and Cushing’s syndrome.
- Individuals who suffer from epilepsy.
- Individuals who experience frequent migraine headaches.
- Individuals who have contract Lupus.
Resources
- Olfactory Dysfunction and Disorder
- Neurotoxic Exposure and Olfactory Impairment (PDF)
- Prevalence of Olfactory Impairment in Older Adults (PDF)
- Medicine Net: Definition of Olfactory Disorder
- Smell & Taste Disorders
- Clinical Evaluation of Olfactory and Gustatory Disorders (PDF)
- Gustatory and Tongue Disorders (PDF)
- What are the Different Taste and Smell Disorders?
- Wexner Medical Center; Smell and Taste Disorders (Chemosensory Disorders)
- Because You Asked About Smell and Taste Disorders (PDF)