Why Our Sense of Taste Changes as We Grow Older
Our bodies change in many ways as we grow older—many of these alterations we see with our eyes. There are also changes that we don’t necessarily notice but experience nonetheless. One area in which we experience changes as we age is our sense of taste. This article examines how our sense of taste changes as we grow older.
Evolutionary Purpose of Sense of Taste
Our sense of taste fundamentally exists to permit human beings the ability to tell if something we intend to eat is healthy or harmful. In prehistoric times, humans lacked any other natural way to ascertain whether or not a potential food item was healthy than to smell or taste it.
Overview of Potential Harm Caused by Loss of Sense of Taste
At first, when many people consider a loss of sense of taste, they think the issue is not being able to enjoy eating as much. While this certainly is true, more serious consequences are associated with losing a sense of taste. These include:
- Reduction in appetite
- Weight loss
- Poor nutrition
- Weakened immunity
The stark reality is that a loss of taste can even have the ultimate consequence of contributing to a person’s death.
How Humans Perceive Taste
We do not intend for this article to be a text on the science of taste. However, we also understand that many of us do not have a complete understanding of this sense and how human beings perceive taste.
A properly functioning sense of taste occurs when molecules released by chewing stimulate special sensory cells in a person’s mouth and throat. Nearly everyone recognizes our mouths play a role in our sense of taste but do now know the throat was involved as well.
These taste cells, technically known as gustatory cells, send messages through specialized nerves to the brain. It is in the brain that specific taste profiles are identified.
Gustatory cells are clustered within what we know as the taste buds of the tongue, the roof of the mouth, as well as lining of the throat. Many of the small bumps that can be seen on the tip and surface of the tongue, biologically known as papillae, contain taste buds. At birth, most people have between 2,000 and 10,000 taste buds. (That certainly is quite a potential difference from one person to another.)
Humans have the ability to experience five basic taste sensations:
- Sweet
- Sour
- Bitter
- Salty
- Umami
If you are like most of us, you are aware of sweet, sour, bitter, and salty. However, you may not be familiar with Umami. Umami is a savory sensation discovered by a Japanese scientist early in the twentieth century. Specifically, Umami is the taste of glutamate. Glutamate is a building block of protein found in foods like:
- Chicken broth
- Cooked meats
- Some cheeses
Umami is also the taste associated with MSG (monosodium glutamate), an additive often used in foods as a flavor enhancer. You likely have been told that MSG should be avoided because it is not healthy for humans.
The five taste qualities above combine with other oral sensations to produce what is commonly known as flavor. These other oral sensations that work with the five taste qualities mentioned a moment ago to create flavor include:
- Texture
- Spiciness
- Temperature
- Aroma
Relationship Between Sense of Smell and Sense of Taste
There is a tight correlation between our sense of smell and our sense of taste. In fact, as humans, we recognize flavors significantly through our sense of smell.
If you hold your nose while eating a piece of chocolate, you will be able to detect its sweetness and bitterness. Still, you actually will be unable to identify the chocolate flavor. That’s because our sense of smell largely identifies the distinguishing characteristic of chocolate through aromas released during the chewing process.
This interconnection between the senses explains why our ability to identify or enjoy food flavors diminishes when we experience a head cold or nasal congestion. With a stuffy nose, food aromas are unable to reach the sensory cells that detect odors that aid in gustatory sensation. It is important to note that in many cases, a loss of or change in taste is actually due to changes in a person’s sense of smell.
How Aging Impacts a Person’s Senses
In normal bodily functioning, taste bud cells are usually replaced every week or two. After we reach the age of 50, taste bud cells begin to lose their sensitivity as well as their ability to regenerate.
In addition, what is known as olfactory nerve endings and mucus production in the nose may also begin to decline. The combination of these processes weakens a person’s sense of smell. When taste and smell are diminished or impaired, a person may change his or her eating habits. This can occur consciously or unconsciously.
Ultimately, some people may eat too little and lose weight. Others may eat too much and gain weight. This may seem like a mere inconvenience. However, the dietary changes that result from a distorted sense of taste (and smell) can be a serious risk factor for diseases and health conditions that include:
- Heart disease
- Diabetes
- Stroke
A distorted sense of taste and smell can contribute to other illnesses that require a person to adhere to a specific diet.
Many older individuals understandably believe that there is nothing they can do about their weakened sense of taste. However, depending on the underlying cause, a doctor may be able to suggest treatments for a weakened or distorted sense of smell. Alternatively, a doctor might be able to recommend ways to cope with this type of issue. It is important to consult a doctor if you find yourself (or someone you love) complaining of taste issues or developing new or seemingly unusual eating habits.
Other Underlying Causes of Taste Issues or Loss
Issues with a person’s sense of taste can be caused by disruptions in the detection of taste or smell. This can occur because of issues with transmitting gustatory and olfactory messages to the brain or how the brain interprets these messages. The following most common causes of this type of issue include:
- Side effects of certain medications
- Infections
- Head injuries
- Dental problems, such as gum disease, ill-fitting dentures, or inflammation
- Radiation therapy for head and neck cancers
- Chemotherapy
- Dry mouth
- Heavy smoking
- Vitamin deficiencies
- Bell’s palsy
- Sjogren’s syndrome
- Neurological conditions like Alzheimer’s disease and Parkinson’s disease
One type of taste disorder is characterized by a persistent metallic, bitter, or salty taste in the mouth. This is called dysgeusia, and it occurs in older people, usually due to medications or oral health problems.
While numerous medications can cause dysgeusia, those most frequently associated with this side effect include:
- Statins for lowering cholesterol
- Antibiotics
- Medications for lowering blood pressure
- Anxiety medications
- Antidepressants
Discuss gustatory side effects with the prescribing doctor. There may be some type of alternative medication available.
Certain lifestyle choices and environmental factors can also impact a person’s sense of taste. For example, people who smoke often report improved senses of taste and smell after they stop using tobacco products. In some instances, exposure to certain chemicals, including insecticides, solvents, and even allergens, can impair taste. Respiratory infections also impact a person’s sense of taste and smell in some instances. (This is yet another reason why regular hand washing and getting necessary vaccinations are important preventive measures, including for women and men in their Golden Years – or perhaps particularly so.)
Sometimes changes in taste can even indicate the presence of an underlying medical condition. By way of example, during the early stages of type 2 diabetes, an altered taste may occur. This results from fluctuations in a person’s blood sugar or glucose levels. Neurological conditions such as Alzheimer’s disease, Lewy Body dementia, and Parkinson’s disease can also significantly affect a person’s sense of smell and taste.
Diagnosis of Taste and Smell Issues and Disorders
In conclusion, true taste disorders are rare. Indeed, most changes in the perceptions of flood flavors result from a loss of smell. As a consequence, an individual who experiences taste or smell issues is well-served getting a referral to an otolaryngologist. This is a physician who specializes in diseases and conditions of the ear, nose, and throat.
There is no specific treatment available to address the gradual loss of taste and smell that occurs due to the aging process, relief from taste disorders is possible for many older adults. Working with a physician and experimenting with different flavors and foods are the best steps toward safeguarding one’s health and continuing to enjoy nutritious meals as a person ages.