How to get taste back after COVID?

How to get taste back after COVID?

Taste and smell training can help you regain your taste after COVID.

Losing senses of smell and taste is common in viral infections, including COVID-19. These effects last for a variable amount of time in different people. The virus penetrates the cells of the taste buds and also influences the local nervous system. A study involving 2 million participants in 2021 noted that 65% of people who tested positive for COVID-19 also lost their taste and smell.

This loss is, however, reversible, and most people regain these senses within a few weeks. But, some techniques can help you to restore it. First, you should know why you must restore the lost taste.

How is the sense of taste produced?

The taste buds control the sense of taste. These are the clusters of nerve endings in the lining of the mouth and on the tongue surface. These taste buds have very small hair-like structures called microvilli which produce nerve impulses whenever food touches these sites and sends it to the brain. The brain interprets these impulses as tastes.

An adult can have thousands (2000-4000) of taste buds of various types, most of which are on the tongue. These sensory organs are renewed weekly, so that sense of taste is maintained. 

If you are more interested in an overview of COVID-19, then read our comprehensive guide written by Dr Williams, which includes symptoms, causes and testing for COVID-19. 

Why is taste so vital?

As the eyes provide a visual picture of the surroundings, taste and smell tell you about your environment's chemical composition. Losing these senses causes inconveniences and increases the risk of other health issues. It also means you can no longer enjoy delicious food tastes and, more dangerously, you may not be able to detect the presence of dangerous chemicals in your surroundings, e.g., gas, smoke, toxic gases etc.

Additionally, it influences your digestive functions as you can no longer feel the fragrances of food etc. Fragrances in foods are not only pleasant to feel but they are also involved in the digestion process because they influence the release of digestive enzymes. Additionally, the sense of taste is vital for human survival because it influences food choices that are directly related to health and disease.

How does coronavirus infection cause a loss of taste and smell?

The coronavirus pandemic (COVID-19) started in China and spread throughout the globe, causing millions of deaths worldwide. Although the primary site of infection is the lungs, the loss of taste and smell was also reported to be very common in coronavirus infections. According to a study published in the Current Allergy and Asthma Reports in 2020, more than 60% of people experience a loss of taste and smell.

However, the loss is variable with the different variants of Covid and a study noted that it varies between 5-98% of the patients. The latter variant Omicron is the least dangerous for taste as just 17% of the patients have noted the loss. Often, it is the very first and, many times, the most long-lasting complication of COVID-19 infection.

How does COVID-19 influence a person's sense of taste? The exact mechanism is still under investigation, but some well-known interpretations are;

• The virus is believed to damage the taste and smell receptors in the tongue and nose. The taste buds have more receptors for the viruses than the surrounding tissues, and the virus uses these receptors to enter and destroy the cells.

• The choice of virus for various types of taste buds is also different, and a recent study published in Medicine in 2022 noted that the buds of umami, sour, sweet and bitter taste are more influenced than the buds of salty taste.

• It also interferes with the transmission of nerve impulses that transmit messages between the brain and the sensory organs. The loss of smell is the first issue, and it also leads to a loss of taste as the body also uses smell to establish the taste of foods.

Coronavirus variants differ in causing the loss of taste. However, it also depends upon personal food preferences and eating habits.

Is COVID-19 the sole cause of loss of taste?

This virus is not the alone cause of loss of smell. Many other factors are responsible, including;

• Infections (common flu, polio, herpes, sinusitis, pharyngitis, infections of the salivary glands, gum infections etc.)

• Nasal polyps

• Ageing

• Head injuries

• Anticancer chemotherapy

• Nervous diseases, e.g., Parkinson's disease, Alzheimer's disease,

• Hypertensive drugs and other prescription and over-the-counter drugs.

Look for these factors if you think coronavirus is not responsible.

How can you get back the smell?

Regardless of the cause, it is essential to restore the taste. The taste is regained automatically in the majority of cases. According to a recent study published in the Journal of Clinical Medicine in 2021, 88% of the patients recovered the smell and taste within 2 months after recovery. It was found that milder hyposmia (loss of sense of smell) resolves more quickly than severe ones.

What if you are among the few that can't regain taste automatically? There is no specific treatment for taste and smell loss, but some tips can be helpful. For example;

Drugs and medications

If you fail to regain taste, other factors can be responsible, as mentioned above. The doctor can help to find more factors and causes that may contribute to it. Surgery may be needed for some causes, e.g., nasal polyps. Also, some people have reported benefits from the drugs, e.g., vitamin and mineral supplements, sodium citrate, corticosteroids etc., but limited verification data is available.

However, research backing is there for some options. For example;

• A recent study published by European archives of oto-rhino-laryngology in 2021 found that the combined use of olfactory training and oral corticosteroids was effective in regaining the sense of smell.

• A randomised controlled trial study published in the Clinical otolaryngology in 2017 found that intranasal use of sodium citrate helped regain olfactory functions, which have been lost due to infections.

Smell therapy

As smell and taste are interlinked, restoring the smell through the smell training technique (olfactory training) will also help restore taste. This practice involves using different scents to prime the receptors and restores their functionality.

The olfactory system used for smelling has a slight ability to regenerate and restore its functions, and regular exposure to various scents can facilitate this process.

A typical procedure of smell training is;

• Collect the samples of different scents from variable sources, e.g., flowers (e.g., rose), fruits (e.g., lemon), spices (e.g., cloves) and resins (e.g., eucalyptus etc.).

• Sniff each scent regularly and separately for 20-30 seconds. There is no need to take deep long breaths.

• Follow the routine daily, once in the morning and once in the evening.

Carry on the training for 6 months or more if needed. You can also use the commonly available scents around you instead of these. Changing the smells after some time will also help. AbScent, a charity in the United Kingdom, also offers many such smell-restoring techniques. These techniques can help you with many smell and taste disorders.

The efficacy of olfactory training to treat nasal symptoms was evaluated by a review published by the International Forum of Allergy and Rhinology in 2016. The patients receiving the olfactory training experienced a significant improvement in the discrimination and identification scores.

Proper hydration

The sense of taste is closely linked to the production of saliva. If you are not producing enough saliva, it can prolong the recovery of your taste due to a dry mouth. So, staying hydrated is an excellent way to regain your appetite and taste after COVID or other issues.

Drink plenty of fluids and include various fruit juices in your daily routine.

Zinc supplementation

Zinc is vital in physiology as it is essential for the function of around 300 different enzymes. Zinc is required for the normal functioning of the taste buds as it has a role in the maintenance and repair of taste buds. It is also involved in creating nerve impulses in the taste buds.

Although zinc deficiency is rare, some studies have found that zinc supplementation can help people having taste issues due to any reason. The use of zinc supplementation in taste disorders was reviewed by a paper published in the Journal of the American Society of Consultant Pharmacists in 2016.

Some medications can also cause zinc deficiency (e.g., sodium valproate, some antibiotics, some diuretics etc.). Identify if you are taking such drugs and talk to your doctor for proper replacements.

Useful tips

Besides these techniques, some valuable tips can also help. These include;

• Cut out your alcohol intake and aim ultimately to eliminate it as it also depresses the taste and smell.

• Quit smoking as tobacco also interferes with smell and taste

• Practice good oral hygiene through brushing and flossing regularly, as it will prevent gum and oral diseases which can influence taste.

• Change your diet to add more flavours to your food. Eat food containing all essential nutrients, including essential oils.

• Add spices, e.g., ginger, lemon, peppers, lime, fresh herbs etc. It will add more flavours and help to restore the taste.

How long will the recovery take?

The recovery, in most cases, is spontaneous, but the time varies for each person. Some people may start recovering within days; others may not fully recover for months. However, if you are worried that your taste has not been restored despite all these techniques, you should consult the doctor.

Mouth health is essential for the proper functioning of taste buds. Our Healthy Mouth Care page has various products and information about mouth care. Click here to visit the page.

When should you see a doctor?

You should seek an appointment with an ENT specialist if your sense of taste or smell doesn't recover after a few weeks of recovery from COVID-19. You should consult the ENT specialist if answers to these questions are affirmative.

• The loss of taste and smell is severe.

• The loss is prolonged, and there are no signs of recovery.

• The loss has arrived suddenly.

• The loss of taste and smell is not explainable.

An ENT specialist will determine the underlying health issue and may use diagnostic tests, e.g., nasal endoscopy, MRI, CT scan, X-rays etc., for definitive diagnosis and will intimate treatment after diagnosis, which can be as simple as over-the-counter decongestants or may require a surgical procedure.

Nasal congestion and the blockage of the nasal passages can also cause loss of smell (and a subsequent loss of taste). We have various products to resolve this situation. Click here to view our products. You may need online consultation to order some of these products.

Bottom-line

Loss of functioning of the olfactory nerves and loss of taste are among the long-term COVID symptoms. But, these are reversible in the majority of cases. If the loss is not reversed within 2 weeks after recovery, it could mean some underlying condition. You should take the help of a doctor to sort out this issue. However, in uncomplicated issues, a smelling therapy for olfactory dysfunction, proper hydration and vitamin and mineral supplementation is enough to help in recovery.

Before worrying about taste loss, you need to establish whether the cause is COVID. Our COVID-19 Antibody Blood Taste does this as it detects the antibody levels after COVID infections and uses just the blood from a single prick. Click here to get your kit.

If you are experiencing taste loss lasting several months and need to consult the doctor, Welzo health professionals can guide you. Click here for online consultation.