Introduction:
Has anyone ever wondered how life would be without the taste and smell of our favorite delicacies? The smell and taste sensations play an important role in our life by helping us to differentiate between different tastes and smell. With aging, the ability to differentiate between different tastes and smells reduces either due to any disorders with age or physiological changes (changes in the body with age) in the sensory organs. However, it is difficult to detect sometimes the changes in taste or smell is due to aging or due to underlying medical conditions.
What Is the Incidence of Change of Smell With Age?
More than 75 percent of people above 80 years of age in the general population lose their ability to smell.
What Is the Incidence of Change of Taste With Age?
The incidence of change in taste is around two-thirds of the people in the age group of 80 to 90.
How Does the Ability to Smell Reduce With Aging?
Olfactory nerves (the first cranial nerve) supply the nose and help perceive smell sensation with the help of olfactory receptors present on the nerve. Normally the olfactory (the first cranial nerve) receptor or neurons cause the transfer of chemical impulses (air particles) to electrical signals, which are perceived by the olfactory nerve (the first cranial nerve), which further passes these electrical signals to the olfactory bulbs (round mass of tissue present in each nasal cavity) from where it reaches the olfactory tract (connects the olfactory bulb to the brain).
But with the aging ability, the smell diminishes due to:
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The number of olfactory fibers and olfactory receptors reduces with age.
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The olfactory neurons or receptors start dying automatically by programmed cell death (apoptosis).
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The regeneration capacity of olfactory (the first cranial nerve) neurons is lost with age.
What Are the Signs and Symptoms of Loss of Smell Seen With Aging?
There are several clinical manifestations of the loss of smell that are associated with the process of aging. Mentioned below are a few signs and symptoms of loss of smell seen with aging.
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Inability to identify and differentiate between different smells.
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Loss of weight due to reduced eating because of loss of smell.
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Altered eating habits with aging.
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Chewing difficulties due to the absence of teeth and the presence of dentures.
How Does the Ability to Taste Reduce With Age?
Our tongue has some tiny elevated bump-like structures called papillae. Four types of papillae are fungiform, filiform, circumvallate, and foliate. Each of these papillae contains numerous taste buds. Each taste bud contains more than 100 taste receptors which are long, elongated, and cylindrical cells that get renewed after every eight to ten days. One end of these taste receptors contains finger-like projections (microvilli) which open up in the oral cavity, and the other end of the receptor is attached to the glossopharyngeal nerve (the ninth cranial nerve), chorda tympani nerve ( branch of the facial nerve) and vagus nerve (tenth cranial nerve) which are distributed based on the location of taste buds and helps to perceive the taste.
But with aging, the ability to sense the taste reduces due to:
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The regeneration potential of the taste receptors loses with aging.
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Reduction in the number of taste receptors with age.
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Altered opening or closing of ion channels for different types of tastes.
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Reduction in salivary flow with age.
What Are the Conditions That Cause Loss of Taste and Smell?
The diagnosis of the medical condition remains unnoticed many times due to difficulty in differentiating between the loss of smell and taste due to aging and underlying medical conditions. Different conditions responsible for loss of taste and smell are:
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Nerve Disorders: Like Alzheimer's disease, epilepsy, and facial nerve paralysis.
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Nutritional Deficiencies: A deficiency of vitamin A, zinc, and B12 results in swollen tongue and loss of taste.
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Chemotherapy: Patients on chemotherapeutic drugs for cancer treatment lose taste sensation gradually.
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Radiotherapy: Patients on radiotherapy lose the smell and taste sensation.
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Infections: Bacterial, viral, and fungal infections cause loss of smell and taste.
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Smoking: Loss of taste and smell sensation occurs in chronic smokers.
How To Diagnose Loss of Smell and Taste?
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History and Clinical Examination: Keeping aside the age factor, the complete history of the patient for the presenting symptoms of loss of taste or smell sensation and previous radiotherapy sessions with drug history should be noted. A thorough clinical examination is done by an ENT (ear, nose, and throat) specialist to determine any nasal abnormalities, underlying bacterial or viral infections, and nerve disorders are done regardless of age factor.
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Blood Investigations: Blood investigations to rule out any nutritional deficiencies.
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Computed Tomography (CT) Scans: CT scan is done to rule out any nerve disorders present.
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Biochemical Tests: It is done to check for the presence of underlying endocrine (gland) disorders.
How To Manage the Loss of Smell and Taste With Age?
Loss of taste and smell with age can be managed by :
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Keeping the body hydrated by drinking plenty of fluids.
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Managing underlying nutritional deficiencies by taking vitamin supplements as prescribed by the doctor.
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Adding flavors and aromas to the food enhances the taste.
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Cleaning the mouth by using mouth rinses after each meal.
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Trying to eat bright-colored foods like carrots, broccoli, and tomatoes helps to cope with the loss of smell and taste problems.
Conclusion:
Loss of smell and taste sensation with age affects the quality of life of the elderly, as they end up losing weight due to altered eating habits and weakness because of nutritional deficiencies due to reduced appetite. Adding more flavors and aroma to the food with different varieties of food on the plate can help to cope with the nutritional deficiencies and health issues associated with loss of taste and smell with aging. So by doing some experiments with the food, one can still enjoy eating with age.
