Fuel Shortage: Can It Change Our Taste Buds?

Our sense of taste is largely controlled by our taste buds, which are tiny organs located on the tongue, roof of the mouth, in the oesophagus, and back of the throat. Each taste bud contains receptor cells that are responsible for reporting the sense of taste to the brain. Taste buds receive signals from tiny molecules that are released when we chew, drink, or digest. This is how we experience the five types of taste: bitter, salty, sour, sweet, and umami (savoury).

There are many reasons why our sense of taste may change. Taste buds regenerate quickly when we are younger, but over time, they don't reproduce as quickly, or at all. Remaining taste buds shrink as we get older, resulting in a diminished sense of taste. Typically, older people notice this loss of taste with salty or sweet foods first.

Other factors that can affect our sense of taste include viral infections, certain medications, dental problems, smoking, head or facial injuries, cancer treatment, vitamin deficiencies, and poor oral hygiene.

Taste buds and aging

As we age, our senses of smell and taste can change, and we may find certain foods less flavorful than before. This is due to a combination of factors, including the loss of taste buds, shrinking of remaining taste buds, and a decrease in smell sensitivity.

Loss of Taste Buds

People are born with approximately 9,000 taste buds, but this number starts to decrease between the ages of 40 and 50. This loss of taste buds can lead to a reduced ability to distinguish basic tastes: sweet, salty, sour, and bitter.

Shrinking of Taste Buds

Even the remaining taste buds may shrink and become less sensitive with age. This shrinkage can cause a decrease in taste sensitivity, particularly for salty and sweet flavors, which tend to weaken first.

Decrease in Smell Sensitivity

In addition to the changes in taste buds, the sense of smell also starts to fade, typically after the age of 70. This decline in smell sensitivity exacerbates the loss of taste because smell is crucial for our perception of flavor.

Impact on Nutrition and Appetite

The loss of taste and smell can have significant impacts on nutrition and appetite. The aroma of food stimulates appetite, so a diminished sense of smell may lead to reduced interest in eating, especially in fruits, vegetables, and other nutritious dishes. This can result in unintentional weight loss or malnutrition due to insufficient intake of essential nutrients.

Additionally, saliva production decreases with age, leading to dry mouth and swallowing difficulties. This further contributes to the changes in taste perception.

While the exact cause of these age-related changes is still debated, it's important to be aware of their potential effects. Accepting and adapting to these changes is crucial for maintaining a healthy and enjoyable relationship with food as we age.

Loss of smell

Our sense of taste is closely linked to our sense of smell. Taste buds pick up on flavours, including sweet, salty, sour, bitter, and umami (savoury). At the same time, our sense of smell lets us enjoy the aromas of food. When something goes wrong with either of these senses, our sense of taste can change.

• Viral infections: The common cold, flu, and COVID-19 can cause a temporary diminished sense of smell.
• Medications: Certain medications, both prescription and over-the-counter, can alter the senses, especially antibiotics and blood pressure medications.
• Dental problems: Gum disease, a tooth abscess, thrush, or dry mouth can affect the sense of taste.
• Smoking: The toxic chemicals in cigarettes interact with the tongue, causing taste buds to lose their shape and become flatter.
• Head or facial injuries: Trauma to the head, neck, or brain can damage the olfactory nerves that signal scents to the brain.
• Nasal polyps: These soft, noncancerous growths on the lining of the nasal passages or sinuses can impact the senses of smell and taste.
• Cancer treatment: Some types of cancer and cancer treatments can alter the signals between the nose, mouth, and brain.
• Vitamin deficiencies: Loss of taste and smell could be a sign that the body is low on certain vitamins, particularly zinc.
• Genetic factors: Genetic disorders such as familial dysautonomia may cause a complete or severe depletion of taste papillae, resulting in a reduced ability to perceive tastes.
• Environmental factors: Exposure to toxic chemicals and industrial agents, as well as internal sources such as liver and kidney failure, can adversely affect the sense of smell by interfering with the chemical composition or quantity of saliva, changing the oral mucus membranes, and reducing the number or function of taste receptor cells.

Medication

Drug Types That Affect Both Taste and Smell

• Antibiotics: Amoxicillin, azithromycin, and ciprofloxacin
• Blood pressure medication: Amlodipine and enalapril
• Statin drugs (lower cholesterol): Atorvastatin, lovastatin, and pravastatin
• Thyroid medication: Levothyroxine

Drug Types That Affect Taste Only

• Pain relievers: Aspirin, ibuprofen, and acetaminophen
• Blood pressure medications: Furosemide, lisinopril, propranolol, hydrochlorothiazide, and triamterene
• Central nervous system stimulants (ADHD/narcolepsy/weight loss): Amphetamines
• Diabetes drugs: Metformin and insulin
• Asthma drug: Albuterol
• Antacids: Ranitidine and omeprazole
• Mental health drugs: Amitriptyline, bupropion, trazodone, and diazepam
• Vitamins: Potassium and vitamin D2

The changes in taste caused by medications can manifest in several ways, including a loss of taste (ageusia), decreased taste (hypogeusia), heightened taste sensitivity (hypergeusia), or an unpleasant/altered taste (dysgeusia). Dysgeusia is often described as a bitter, metallic, or sour taste.

It is worth noting that the effects of medication on taste may not be immediate, and it could take months or years for a taste disorder to develop. Additionally, older individuals who take multiple medications are at a higher risk of experiencing taste alterations. If you are experiencing changes in your sense of taste, it is important to consult a healthcare professional before discontinuing or altering your medication.

Dental problems

Taste disorders, such as dysgeusia, can be caused by dental problems. Dysgeusia is characterised by a particularly foul, metallic or rancid sensation in the mouth. It can be caused by a number of issues, including:

• Poor oral hygiene
• Gum disease, such as gingivitis or periodontitis
• Thrush, a yeast infection of the mouth
• A tooth abscess, or infection of the root of the tooth
• Dry mouth, due to lack of saliva flow/production
• Dentures that are not properly cleaned or cover part of the mouth's upper palate

In addition, nerve damage due to dental procedures can also cause taste disorders. This may be due to factors such as the proximity of the chorda tympani nerve to the surgical site, retraction of the lingual flap, or extraction of unerupted teeth.

It is important to note that determining the underlying cause of taste loss can be tricky, as taste is closely associated with smell, and there may be many potential medical or dental reasons for the problem. If you are experiencing taste disorders, it is recommended to seek prompt attention from a doctor or dentist.

Smoking

The impact of smoking on taste is dependent on the level of smoking exposure. The more cigarettes smoked, the greater the damage to the taste buds. This is reflected in the higher number of taste buds and better taste sensitivity found in non-smokers compared to smokers. The effect of smoking on taste buds is reversible, with studies showing that quitting smoking leads to a rapid recovery of taste sensitivity. However, this recovery can take time, with some studies reporting a return to normal taste sensitivity after two weeks, while others reporting a longer recovery period of up to eight months.

The sense of smell is also affected by smoking, with smokers being six times more likely to have a poor sense of smell than non-smokers. This is significant as the senses of smell and taste are interconnected, and a reduction in the sense of smell can further impair one's ability to taste.

In addition to the direct impact on taste buds and smell, smoking can also lead to other health issues that may contribute to changes in taste. These include respiratory infections, xerostomia (dry mouth), and changes in salivary flow rates, all of which can affect the perception of taste.

Quitting smoking is the best way to restore taste and smell function and reduce the risk of developing serious health conditions associated with smoking.

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