Dysgeusia or taste impairment is a taste disorder and can occur due to an underlying disease such as sinus infection, common cold, diabetes, etc. Altered taste perception has an adverse effect on the quality of life.

Impaired taste means that your sense of taste is malfunctioning. It can also mean the absence of taste or can refer to an altered sense of taste such as a person feeling a metallic taste in his mouth.

Majority people experience impaired taste temporarily due to loss of a part of their sense of taste. Although, it is very rare to lose the sense of taste entirely.

About 75% of old people, above the age of 80, are likely to have taste impairment. Let us understand what taste impairment is and know the causes, symptoms, and treatment of this disorder.

What is the link between taste and smell?

The flavor in food that you can taste is due to a combination of your ability to smell and taste. In some cases, there may be an issue with your sense of smell while your taste buds function perfectly.

In such cases, an otolaryngologist (ear, nose and throat specialist) determines if you have a smell disorder.

Causes of impaired taste (Dysgeusia)

Common cold or some other respiratory illness can impair taste due to temporary interruption of smell. Other conditions that affect the sense of taste are –

  • Common cold
  • Flu
  • Sinus infection
  • Salivary gland infections
  • Throat infections (such as pharyngitis)
  • Smoking
  • Inflammation of the gums (such as gingivitis or periodontal disease)
  • Thyroid medications or cancer treatment (chemotherapy) (1)
  • Sjogren’s syndrome (autoimmune disease)
  • Vitamin B12 and zinc deficiency (3)

Disorders of the nervous system cause an altered sense of taste. Nervous system disorder affects how nerves send messages to the rest of the body, and the organ controlling sense of taste may be affected by nervous system disorders causing dysgeusia.

Bell’s palsy and multiple sclerosis patients also experience dysgeusia. Let us know about the common causes in detail –

1. Medicines

Metallic taste sensation is the most common symptom of taste impairment, and this is majorly due to certain medications. There are more than 250 medicines which cause taste disorders.

2. Cancer treatment

Dysgeusia is a side effect of chemotherapy and radiation therapy. More common in the case of head and neck cancers, though can occur in any cancer treatment.

Doctors need to address this side effect since patients lose appetite and may eat less. Not eating properly while sick can cause malnutrition and weight loss. The loss of taste due to chemotherapy can be temporary or permanent.

3. Diabetes

People with undiagnosed Type 2 diabetes mellitus experience taste impairment. Rather dysgeusia can be one of the early symptoms of diabetes since the altered taste varies with fluctuations in blood sugar levels and hence is an early clinical sign for diabetes. (4) (5)

Symptoms of dysgeusia

Dysgeusia manifests as an unpleasant, lingering sensation in the mouth. People who experience taste impairment complain of foul, rancid, metallic or salty feeling.

Dysgeusia is attributed to changes in the body (aging), certain diseases, vitamin deficiency, prescription medicines, and cancer treatment. (2)

Treatment for dysgeusia

Treatment with pilocarpine and artificial saliva

Oral pilocarpine and artificial saliva can increase the flow of saliva from salivary glands. Artificial saliva mimics natural saliva and helps lubricate your mouth. Pilocarpine stimulates the salivary gland and activates production of saliva.

Zinc supplements

Most distortion in the sense of taste is caused due to deficiency of zinc. If dysgeusia is caused due to zinc deficiency, then you can take 25 to 100mg of zinc supplements to help treat your symptoms.

You will need to consult a doctor for the diagnosis of the same.

Infusion of zinc in chemotherapy

Zinc supplement infusion in chemotherapy can help regain the sense of taste in cancer patients who experience loss of taste sensation.

Zinc overdosage can cause serious adverse effects on the patient’s immune system, therefore, cancer patients who have very low immunity are not given zinc infusion along with chemotherapy.

Changing medication

Certain medications cause dysgeusia, in such cases the condition can be reversed by changing the medicine and giving a suitable alternative.

For example, Eprosartan can cause loss of taste and tongue numbness. All symptoms cease if a doctor prescribes Valsartan instead of Eprosartan.

Alpha lipoic acid

Alpha lipoic acid is a natural antioxidant produced by human cells. You can also consume it in the form of capsules or food rich in alpha lipoic acid (red meat, yeast, etc.).

Alpha lipoic acid is known to improve nerve conduction velocity. A person differentiates flavors with the help of nerves in the tongue, alpha lipoic acid causes an alteration in neuropathy and also treats burning sensation in the mouth. (6)

Lifestyle changes

In a majority of cases, lifestyle changes can help improve taste impairment.

  • Quitting smoking can allow people to taste food fully. Ex-smokers regain their sense of taste as early as two days after they quit smoking.
  • Proper oral hygiene can reverse gingivitis which in turn can improve the sense of taste.
  • Brushing and flossing help eliminate plaque from the mouth and protect teeth from decay and help a person regain the sense of taste.

Ongoing research on taste disorders

Basic and clinical investigations of smell and taste disorders are undergoing in chemosensory research centers. The scientist are exploring how to

  • Develop new diagnostic tests.
  • Prevent effects of aging on taste and smell.
  • Improve treatment method and rehabilitation strategies.
  • Understand the link between taste disorders and change is diet and food preferences among the elderly and people suffering from chronic illness.

Over to you

Do not delay your visit to the doctor if you experience a change in taste perception. It could be a sign of an underlying disease such as diabetes. Also, you can ask your doctor to change medicine if it is the main cause of change in taste.

Bring in some positive lifestyle changes in your life such as take good care of your oral health, quit bad habits such as smoking, etc. All these positives might keep you safe from dysgeusia.

Dysgeusia or taste impairment is a taste disorder and can occur due to an underlying disease such as sinus infection, common cold, diabetes