Why you need to feel an unpleasant taste. Why is there a scent that doesn't exist? How does the taste analyzer work?

How does it work

For research in the field of smell, the Nobel Prize was awarded six years ago. It was shared by the Americans Richard Axel and Linda Buck, who figured out exactly how the human brain recognizes odors. Previously, it was only known that they are caught by some olfactory cells, which send a signal to a special part of the brain called the olfactory bulb. It turned out that special genes are responsible for the formation of olfactory receptors - we have about a thousand of them, which is about 3% of the total. The olfactory receptors associated with them are located in the upper part of the nasal cavity and occupy an area approximately the size of a ruble coin. It is they who detect the odorous molecules of odorants - substances that emit odors. Each receptor is designed to perceive and then transmit a signal to the olfactory center of the brain of only a few specific odors. As a result of the union of genes and olfactory receptors, about ten thousand combinations are formed - that is how many odors the human brain can recognize. But do we need the ability to distinguish so many smells, given that not all of them are pleasant? It turns out that it is necessary, and how!

Why do you need

During a cold, it seems: all food is equally tasteless. This is because the sense of taste is closely related to the olfactory ducts. With a strong runny nose, taste sensations are smeared. The sense of smell gives us the opportunity to feel the taste of food, and the better it is developed, the tastier the food. And we still wonder how cats and dogs can eat the same food every day and not complain. Perhaps they, with their much more developed sense of smell than ours, and the simple “Whiskas” open every day with new taste nuances? Another important function of the sense of smell is signaling. If the smell contains information about a potential danger, the brain immediately gives a command to the respiratory center, and it freezes for a moment. People, unfortunately, do not always have time to feel this signal of the brain and, holding their breath, take their legs away from the dangerous place. There is a known case of mass poisoning in the subway, when the poisonous gas was given the smell of freshly cut grass. Only especially vigilant passengers managed to figure out that there is nowhere to take such a scent in the subway, and they protected their respiratory organs. The rest paid with severe poisoning. The natural gas used in gas stoves does not smell of anything at all, and an unpleasant smell is given to it on purpose - otherwise there would be immeasurably more victims of household poisoning around the world. Aromas are also widely used in trade - identical to natural coffee and lemon are sprayed in front of advertising stands, the smell of freshly baked bread is used to increase consumer activity. And even, they say, the popularity of McDonald's does not fade precisely thanks to the special aroma derived by chemical means, well known to hamburger lovers all over the world. But in addition to the undeniable economic and other benefits, one should not ignore such an insignificant function of smell as... giving pleasure. After all, it is often very pleasant to sniff something.

What flavors do we like?

Almost everyone loves the smells of cut grass, fresh newspapers, ozonized air after a thunderstorm, coniferous forest or coffee with cinnamon. But there are also more exotic preferences. Some, for example, like the smell of the subway, shoe stores, damp basements. There are connoisseurs of the aromas of gasoline, asphalt, burnt matches, acetone, small puppies and kittens, new tights, ice cream sticks, Vishnevsky's ointment... The list is endless. But, if you think about it, such a variety of preferences is a good field for social interactions. And if we return to the list of more familiar fragrances, then, along with the smell of kittens and new tights, women, of course, most of all like the way it smells ... right, beloved man. And here, perhaps, the most important function of smell is turned on: the ability to help in finding a partner.

As intended by nature

Let's leave aside social, cultural and other human factors and consider the process of finding a partner from a biological point of view. People are attracted to the smells of those whose gene set is different from their own. Women subconsciously perceive a man with a similar set of genes as a relative and do not see him as the father of their future children - nature has taken care of excluding possible gene complications in offspring. The brain then continues to process the signals picked up by the olfactory system. A complex mechanism of biochemical processes in the body is launched - in a man, the amount of testosterone increases, and in a woman - estrogen. The response signals provoke an increase in attractive smells - and people like each other more and more. In women, the sense of smell is sharper (and even stronger during the period of ovulation!), Therefore, it is considered: they choose a man. This is justified - after all, they are responsible for the continuation of the family.

The future is in the sense of smell

Researchers from Tel Aviv found that depressed women do not smell. Therefore, if the nose did not warn about the arrival of spring, perhaps the psychological state of a person needs to be corrected. Researchers from South Korea have found that the invigorating and stress-reducing effect of coffee is caused not by the drink, but by its smell. To feel better after a sleepless night, (it is not necessary to drink coffee, just smell the coffee beans). German researchers sprayed various fragrances near sleeping people. It turned out that the smell directly affects the images seen in a dream. If the bedroom smells of roses, dreams will be pleasant. And scientists from Yale University discovered that such a serious problem as obesity is associated with the sensitivity of the olfactory system. People abuse products that are harmful to the figure because certain parts of the brain are too receptive to their smell. It seems that in the future, it is with the help of smell that humanity will begin to cope with depression, fight excess weight, see dreams on demand and find ideal life partners. They say that the time is not far off when a film screening in cinemas will be accompanied not only by the sound sequence (even at the beginning of the 20th century it seemed fantastic), but also by the corresponding smells. It is curious to know how the air smells in the homeland of the blue giants - Pandora.

The same taste can be perceived differently by each of us. Someone loves lemon - it seems sweet, but someone just can't stand the sour taste of citrus fruits.

AiF.ru explains what determines different taste preferences and why people have certain eating habits.

How many taste sensations are there really?

Even in ancient times, scientists singled out only four basic tastes - bitter, sour, sweet and salty. But in the early 1900s, a Japanese scientist identified another taste. Kikunae Ikeda identified glutamic acid as the fifth taste. He called it umami, which means "pleasant spicy taste." A person feels this taste if salts of some organic acids are present in food. These are usually monosodium glutamate, sodium inosinate, and sodium guanylate. These substances are found in foods such as parmesan cheese, beef, chicken, pork, mushrooms, seafood, and seaweed. Some vegetables also taste umami: tomatoes, asparagus, cabbage, and carrots.

To recognize taste sensations, a person is helped by certain receptors located on the tongue. The tongue as a whole can be roughly divided into several regions - the back of the tongue is responsible for the perception of bitter taste, the side of the tongue is responsible for the sour taste, the front of the tongue is for the salty taste, and the tip is for the sweet taste. Scientists say that the back part should be responsible for the fifth taste of umami.

Taste receptors. Photo: commons.wikimedia.org

Why do we prefer certain flavors?

Sweet

Many prefer sweet foods during periods of depression and intense mental work. Nervous and mental overstrain lead to a faster consumption of sugar, which is why you want to refresh yourself with sweets in order to replenish your glucose reserves. Also, thanks to the sweet, the hormones of happiness are formed in the body - serotonin and endorphin.

bitter

The attitude to bitter taste can be different. One and the same taste may seem unbearably bitter to some, but to others it does not play any role. But if you always want bitter, then you have recently suffered or not cured the disease, and craving for bitter food is a sign of residual intoxication of the body.

Salty

Scientists have found that those who crave salty foods lack certain minerals in their bodies. Such a desire may indicate a strong stress that you are experiencing: due to stressful everyday life and fatigue, the body is especially in dire need of natural minerals and salts. Also, this taste attracts people with dehydration.

Sour

One of the reasons for the addiction to sour is a lack of vitamin C. Therefore, a sudden desire to eat something sour can serve as a signal of an upcoming cold. The desire to taste sour can also speak of low stomach acid.

Umami

Umami-flavored food is appealing to the palate and some people may even develop addiction. This property of the fifth taste is used by fast food manufacturers. There is also an opinion that umami is perhaps the first taste that a person recognizes. Sufficient amounts of salts of organic acids are present in breast milk.

Why do different people perceive the same taste differently?

Different people may perceive the same taste differently. It depends on several factors.

different number of receptors

People have different numbers of taste buds. Those who have more of them feel the taste of food more intensely. Professional wine or tea tasters, for example, have twice as many of these receptors as the average person.

Aversion to a certain taste at the subconscious level

The perception of a certain taste depends on personal experience. If once a person was poisoned by fish, there is a chance that even its sight and smell will be unpleasant for him. The body will be reminded that everything associated with this taste is potentially inedible.

Individual characteristics

Many people cannot eat certain foods. For some, for example, milk is a tasty and healthy product, and for some it is a taboo. The body of such people does not produce lactase, which is necessary for the breakdown of milk sugar. Also, the taste sensations of a person largely depend on the feeling of hunger - tasteless food always seems to be tastier to the hungry.

Olfactory disturbance

In addition to taste, our sense of smell is also affected. With a severe runny nose, any, even the most favorite dish, seems tasteless. How important the sense of smell is in the perception of taste can be understood by pinching your nose. The coffee will just become bitter.

Diseases of the internal organs

Some diseases can affect taste sensations. For example, a feeling of bitterness in the mouth can be caused by cholelithiasis, diseases of the liver and biliary system, the use of certain drugs: antihistamines, antibiotics, St. John's wort, sea buckthorn oil.

Pregnancy

A sudden change in tastes can be the cause of pregnancy. In such a state, it is not surprising that a passionate fan of pickles can turn into a notorious sweet tooth, and a lover of chocolates, ice cream and jams suddenly wants to eat everything salty and spicy.

Genes

Sometimes it seems to us that we eat what our parents taught us to eat. But scientists are increasingly inclined to believe that the choice is made for us by genes. For the first time, the gene responsible for the bitter taste was discovered only in 2003. It turned out that it encodes the receptor protein of taste cells. Therefore, different people distinguish bitterness in varying degrees.

cultural traditions

Taste habits are formed in different countries in different ways. For example, some insects and grasshoppers in Africa and Asia are tasty and nutritious food, but they are disgusting to a European person.

Urgent problems of the body

Sudden taste cravings speak of the vital needs of the body. Salty cravings are often due to a lack of sodium, usually after visiting the gym. If suddenly a person begins to lean on black bread, this may mean that he lacks B vitamins, and iron for meat. If a person eats a lot of butter - vitamin A, if he reaches for seaweed - iodine. If you dream about bananas, then the body needed magnesium.

Compared to other senses (such as the sense of smell), the organ of taste is not very sensitive. It has been proven that a person needs 25,000 times more substance to taste than to smell it.

Despite this, the combination of four types of taste buds that perceive salty, sour, bitter or sweet form a wide range of sensations, which, after analysis in the brain, allow you to feel even the different flavors of food. Some strong taste sensations, such as hot or spicy food, are perceived by pain receptors on the tongue.

Possible taste disorders

Loss of taste is often associated with damage to the facial nerve. This nerve is associated with facial muscles, but one of its branches contains taste fibers coming from the anterior two-thirds of the tongue. In case of violation of taste, damage to the nerve occurs before the zone of separation of this branch from it - next to the tympanic membrane.

Frequent infections of the ear can lead to the development of mastoiditis and, as a result, damage to the facial nerve.

Even when a nerve is damaged on one side, information is sent to the brain via the facial nerve of the other side. If the nerve associated with the posterior third of the tongue is also damaged, there may be a significant loss of taste.

Taste can be disturbed in facial nerve paresis, when it suddenly becomes inactive for various reasons. Complete loss of taste is very rare, since it is unlikely that all taste nerves will be affected at the same time.

More often there is a complete loss of smell (for example, after a traumatic brain injury), which leads to a violation of taste sensations.

Why does bad taste occur?

People with depression often develop a bad taste in their mouths. The reason has not been studied, but it is possible that this is due to the close interaction of taste and smell. The centers of the brain that analyze odors are connected to the emotion centers of the limbic system. It is hypothesized that mood changes can distort taste and smell. Another type of unpleasant taste sensation occurs in some people as a precursor to an epileptic seizure. This indicates that the focus of abnormal electrical activity that caused the seizure is located in the parietal or temporal lobes of the brain.

Answers from a neurologist to some questions from readers

I recently had a severe traumatic brain injury with a skull fracture. Now I seem to have recovered, but my taste is almost completely absent. Does this mean that the nerves leaving the tongue were damaged?

Probably not. It looks more like both of your olfactory nerves are damaged. Loss of smell may not be as obvious and may be manifested by loss of taste. You can test this by placing a small piece of salt directly on your tongue. If your sense of smell is affected, you will feel the salt normally.

I noticed that after I quit smoking, I taste food better than before. Does this mean that smoking damages the taste buds?

Smoking probably desensitizes your taste buds, but your improved sense of taste may be due to the recovery of your olfactory receptors after smoking.

The sense of smell is one of the senses that a person needs for a fulfilling life. And its violations impose tangible restrictions on the emotional state and become a real problem. Among the disorders of smell, there are also those when the patient is haunted by a smell that is not really there. Everyone is interested in the question of the origin of unpleasant symptoms, but only a doctor will help determine the source of disorders in the body.

The smell is sensed through the reaction of olfactory receptors located in the mucous membrane of the nasal cavity to certain aromatic molecules. But this is only the initial section of the corresponding analyzer. Further, the nerve impulse is transmitted to the areas of the brain responsible for the analysis of sensations (temporal lobes). And when a person smells that are not there, this clearly indicates some kind of pathology.

First of all, all the reasons should be divided into two groups. The smell may be quite real, but not felt by others until the patient speaks to them at close range. This is likely in the following situations, covering the practice of ENT doctors and dentists:

• Fetid coryza (ozena).
• Sinusitis (sinusitis, frontal sinusitis).
• Chronic tonsillitis.
• Caries, pulpitis, periodontitis.

These diseases are accompanied by the formation of pus, which gives an unpleasant odor. A similar situation may appear in those who suffer from diseases of the gastrointestinal tract (gastritis, peptic ulcer, cholecystitis and pancreatitis). Food that has entered the digestive tract is processed worse, and during belching or reflux, unpleasant odor molecules come out. A similar problem may not be noticeable to others if they do not come close.

Some people have a lower threshold for olfactory perception. They smell better than others, so sometimes they encounter misunderstandings from others. Some fragrance may be too faint to be smelled by anyone else. And this feature should also be taken into account by the doctor.

A separate group of reasons are those that are associated with the defeat of any of the departments of the olfactory analyzer. The odors that have appeared are not conveyed to others, since their formation, transmission and analysis in a particular person are disturbed. And although some other (quite real) one can serve as the basis for an unpleasant aroma, the end result is present only in the mind of the patient and is a problem for him.

There are quite a lot of conditions that manifest as a violation of the sense of smell (dysosmia or parosmia). They include both respiratory pathology with inflammation of the nasal mucosa, for example, rhinitis or SARS, and other disorders in the body:

• Hormonal changes (during pregnancy, during menstruation or menopause).
• Bad habits (smoking, alcohol abuse, drugs).
• Taking certain medications and poisoning with chemicals.
• Endocrine disorders (hypothyroidism, diabetes mellitus).
• Systemic diseases (scleroderma).
• Traumatic brain injury.
• Tumors of the brain.
• Neurosis or depression.
• Psychoses (schizophrenia).
• Epilepsy.

It is necessary to remember about the so-called phantom smells associated with some kind of stress in the past and left a strong impression. In similar situations, they can come to the surface. As you can see, the source of an unpleasant odor can be hidden among a large number of diseases. And some can be quite serious. But do not immediately get scared and look for a dangerous pathology in yourself - the causes of the violations will become clear only after a thorough examination.

Why people perceive certain smells is a rather serious question and requires further research.

Symptoms

Any pathology has certain signs. To identify them, the doctor evaluates the patient's complaints, analyzes the factors that precede the appearance of an unpleasant odor, and conducts a physical examination. It should be understood when an extraneous odor is felt, is constantly present or occurs periodically, how intense it is, what contributes to its disappearance, and what additional symptoms are in the clinical picture. Sometimes only this allows you to establish the cause of dysosmia, but not always.

The aroma that haunts the patient may have a different color. Those who drink citrus tea often smell a burning smell, and hot spices can cause a feeling of the presence of sulfur in them. Along with the distortion of smell, taste also changes, since they are closely related. A severe runny nose, for example, can cause the illusion that the onion has become sweet and smells like an apple.

ENT pathology

The first thing to think about when complaining of an unpleasant smell is diseases of the upper respiratory tract. When the nasal mucosa is damaged, the sense of smell is invariably disturbed, but the patient may not always feel how it stinks of pus or rot. Most often, a similar symptom occurs with sinusitis, chronic tonsillitis or ozen. In the latter case, the smell is so pronounced that others notice it. But besides this, you need to pay attention to other symptoms:

• Violation of nasal breathing.
• Discharge from the nose (mucopurulent or purulent).
• Heaviness in the projection of the paranasal sinuses.
• Dryness of the mucosa and the formation of crusts.
• Pain in the throat when swallowing.
• Plugs on the tonsils.

If we are talking about acute sinusitis, then the purulent process in the sinuses invariably entails fever and intoxication with headaches, but the chronic one gives less pronounced symptoms. With tonsillitis, disorders of the kidneys, heart, and joints are often detected (the result of sensitization to streptococcus antigens). If the sense of smell is impaired due to ARVI, then in the clinical picture, in addition to a runny nose, there will be other catarrhal symptoms against the background of intoxication, for example, redness of the throat and lacrimation.

The pathology of the nose, paranasal sinuses and pharynx is the main cause of the appearance of an extraneous odor, which can only be imagined by others through close contact with the patient.

Diseases of the digestive tract

An unpleasant odor can also haunt those who suffer from diseases of the gastrointestinal tract. Violation of food digestion is the main mechanism of such a symptom. The smell of rotten eggs worries with hypoacid gastritis (with reduced acidity) or duodenal ulcer, it does not appear constantly, but after eating. In the clinical picture, there are other signs of dyspeptic syndrome:

• Belching.
• Nausea.
• Bloating.
• Chair change.

Many feel discomfort in the stomach or pain in the epigastrium. And the concomitant gastroesophageal reflux causes heartburn and further esophagitis. If the gallbladder is affected, then an additional symptom will be a feeling of bitterness in the mouth.

Psychoneurological problems

Many patients with psychoneurological status disorders perceive a smell that is not actually there. It can have both a real prototype (illusion) and be based on non-existent connections (hallucination). The first situation can also occur in a healthy person who has undergone severe emotional stress, but often becomes a constant companion of those who suffer from neurosis or depression. Additional symptoms of pathology are:

• Decreased mood.
• emotional lability.
• Irritability and anxiety.
• Sensation of a "coma" in the throat.
• Sleep disorders.

Characteristic signs will also be somatic functional disorders arising from an imbalance of nervous regulation (increased heart rate, increased sweating, nausea, shortness of breath, etc.). Unlike neurotic reactions, psychoses are accompanied by profound changes in the personal sphere. Then there are various hallucinations (auditory, visual, olfactory), overvalued and delusional ideas, when the perception of the surrounding world and behavior are disturbed, there is no critical understanding of what is happening.

The feeling that it suddenly began to smell like rotten meat can occur with epilepsy. Olfactory and gustatory hallucinations are a kind of "aura" that precedes a convulsive attack. This indicates the location of the focus of pathological activity in the cortex of the temporal lobe. After a few seconds or minutes, the patient develops a typical seizure with tonic-clonic convulsions, short-term loss of consciousness, biting of the tongue. A similar picture also occurs with a brain tumor of the corresponding localization or trauma of the skull.

Neuropsychiatric disorders, as the cause of a foreign smell, are perhaps the most serious situation that cannot be missed.

Additional diagnostics

Smells that others do not feel are an occasion for a detailed examination. It is possible to find out the cause of what is happening only on the basis of a comprehensive diagnosis using a laboratory-instrumental complex. Based on the doctor's assumption based on the clinical picture, the patient is recommended to undergo additional procedures:

• General analysis of blood and urine.
• Blood biochemistry (inflammatory markers, liver tests, electrolytes, glucose, hormonal spectrum).
• Nose and throat swab (cytology, culture, PCR).
• Rhinoscopy.
• X-ray of the paranasal sinuses.
• Computed tomography of the head.
• echoencephalography.
• Fibrogastroscopy.
• Ultrasound of the abdominal organs.

To get the maximum diagnostic value, the examination program is formed on an individual basis. If necessary, the patient is consulted not only by an ENT doctor, but also by other specialists: a gastroenterologist, a neurologist, an endocrinologist, a psychotherapist. And the results obtained make it possible to establish the final cause of the violations and remove the unpleasant odor that seemed to the patients.

In modern medical practice, there is often a complete or partial loss of taste. All these cases are associated with various failures that occurred in the human body. But most often they are found in otolaryngology. It is at the reception of this specialist that patients often ask: “What should I do if I no longer feel the taste of food?” After reading today's article, you will understand why such a pathology occurs.

Causes of the problem

Oddly enough, but most often this pathology develops as a result of neurosis. This is a kind of reaction of the human body to the transferred stress and nervous overload. In these cases, you can hear from the patient not only the phrase “I don’t feel the taste of food”, but also complaints about malfunctions in the gastrointestinal tract, jumps in blood pressure, and heart palpitations.

An equally common cause of such a problem is considered to be infectious diseases of the oral cavity or the presence of a collapsing dental nerve. In this case, an inflammatory process begins in the human body, which affects

Also, such a pathology may be the result of malfunctions in the thyroid gland. Even minimal deviations can lead to serious changes in many systems of the human body.

Doctors often hear the phrase “I don’t feel the taste of food” from those who have been diagnosed with a brain tumor. In this case, this symptom may alternate with a sensation of an unpleasant odor. So, a well-prepared dish of quality products suddenly begins to seem stale.

Which specialists should be contacted with a similar problem?

Before you come to the doctor’s office and voice your complaint “I don’t feel the taste of food” (the reasons why such a pathology occurs were discussed above), you need to understand which particular doctor you need to contact. In this situation, much depends on what accompanying symptoms this pathology accompanies.

If, in addition to loss of taste, the patient complains of loss of appetite, palpitations and jumps in blood pressure, then he should definitely consult a neurologist.

In cases where the pathology is accompanied by dizziness, weakness, vomiting, impaired hearing and coordination of movements, you should first make an appointment with an oncologist.

If a person pronouncing the phrase “I don’t feel the taste of food” complains of nausea, vomiting, heartburn and acute pain in the epigastric region, then it is likely that he needs to examine the gastrointestinal tract.

If the usual foods seem bitter, and each meal is accompanied by the appearance of pain in the right hypochondrium, then you need to visit a hepatologist. It is possible that the loss of sensitivity of taste buds, accompanied by flatulence, defecation disorders, insomnia and irritability, is a consequence of cholecystitis.

Diagnostic methods

A person who seeks medical help and voices the phrase “I don’t feel the taste of food” will need to undergo several additional studies. They will allow you to establish the exact cause that provoked the development of pathology, and prescribe adequate treatment.

First of all, the specialist must determine the threshold for the manifestation of sensitivity. To do this, the patient is alternately offered to determine the taste of quinine hypochloride, sugar, salt and citric acid. The results of the study allow you to create an accurate clinical picture and the extent of the problem. To determine the qualitative threshold of sensations, a few drops of a special solution are applied to certain parts of the oral cavity.

In addition, modern physicians have the opportunity to conduct an electrometric study. Also, the patient is prescribed a number of laboratory tests. They are needed to exclude endocrine diseases. In most cases, the patient is sent for a CT scan.

Why is such a pathology dangerous?

It should be noted that it can cause the development of serious health problems. A person who has begun to wonder: “Why don’t I feel the taste of food?” If not properly treated, they can later be diagnosed with diabetes, cardiovascular and other diseases.

Violation of the receptors can result in a person consuming too much salt or sugar. These attempts to improve the taste of food can lead to serious problems. Often they lead to depression, hypertension and diabetes.

What do you do if you can't taste food?

First of all, you need to make an appointment with a doctor and go through all the studies recommended by him. This will determine the root cause of the problem and prescribe the correct treatment.

So, if the problem was provoked by neurosis, the patient will be recommended to take an individual course, consisting of auto-training, water and magnetotherapy. He will also be prescribed sedative herbal preparations, and in more serious cases, tranquilizers or bromides. If the cause lies in the disruption of the thyroid gland, then usually endocrinologists prescribe drugs to make up for iodine deficiency.

To improve taste sensitivity, you need to quit smoking. Often it is this bad habit that causes such problems. Also, taste sensations can be dulled while taking certain medications, including strong antibiotics. In this case, you need to consult a doctor to recommend other medicines that do not have such side effects.

In addition, you should make sure that your body receives a sufficient amount of vitamins and minerals. To do this, you need to include more fresh vegetables and fruits in your diet. With a loss of taste, spices should not be abused. Otherwise, you risk earning a burn of the oral mucosa.