On anosmia, the loss of your sense of smell and how to regain the sense of smell naturally

While I survived the corona period almost without any problems other than just feel sick for about 2-3 days , I was struck by a stubborn cold two weeks ago after which I used up a truckload of tissues, had to cough a lot and to make matters worse, could no longer smell anything.

Being able to smell well is something that seems obvious, until you suddenly can't anymore. And how boring your life becomes, especially when it coincides with what is at the same time one of the most festive and greyest periods of the year. On the one hand, we have barely seen the sun for weeks, even if we could have seen it during the shortest days of the year. And on the other hand, our senses (eyes and nose) are caressed by delicacies, which in many cases are only eaten around Christmas or New Year's Eve. What a shame it is when you can hardly taste anything of it. 
Or if you are a perfume lover like me and can't smell your own lovely perfume.

This had been going on for 12 days until the sense of smell finally came back, starting with... the smell of bacon my husband was preparing. A week further on and I can smell almost everything though still a bit too faint. 

As it turns out, I am far from the only one who has been struck by a bad cold. That's why I thought it would be a good idea to tell you a little more about the nose and the sense of smell and also what you could do to be able to smell again more quickly.

Human sense of smell is better than we thought

The human sense of smell is as good as that of other mammals, such as dogs and rodents. This shocking conclusion is entirely different from the usual assumption that humans have a weak sense of smell as a tradeoff for their great vision.

Neurobiologist John McGann has been working for years to prove wrong the long-believed myth that discredits human sense of smell, and apparently, he has done so. He says that humans have as many functional odor receptors as other mammals that are considered to have a keen sense of smell, but sometimes people diminish the importance of smell.

We’re like lots of mammals with a perfectly good sense of smell, and if we paid more attention to it, I think we’d realize how important it is to us,” said John McGann.

McGann explained in his paper where this misconception about a poor human sense of smell began. He said that today people believe they don’t have a good sense of smell because of a wrong hypothesis made in the 19th century when French Anatomist Paul Broca stated that the part of the brain that is responsible for processing smell, was quite small if compared to the size of the human body. He said that other mammals have a clearly better sense of smell because their olfactory bulb was bigger in relation to their bodies.

Even Aristotle made a reference to the human sense of smell saying that men generally “smell poorly.” 
“Through a chain of misunderstandings and exaggerations beginning with Broca himself, this conclusion warped into the modern misapprehension that humans have a poor sense of smell. Broca viewed smell as an animalistic sense that drove irrational behavior and thus must be diminished in importance in a rational being with free will.”

This misconception was passed from one generation to another, and now people still believe it. Other scientists have made other studies about the issue, following Broca’s idea. Even Charles Darwin said that the sense of smell was “extremely slight service” to civilized people, meaning that he believed that human’s sense of smell was atrophied as a mark of evolutionary advancement.

John McGann decided to prove wrong these theories beginning this research in the early 2000s. According to his work, humans have about 1,000 odor receptor genes, which is similar to the number of odor receptor genes of mice, which have 1,100. However, some scientists say that counting and making assumption only based on odor receptor genes is not a solid indicator of the capacity to smell something.
For instance, cows have nearly 2,000 odor receptor genes, and that would mean they smell better than dogs.

Another thing, which according to McGann is misconceived, is the fact that it is believed that two-thirds of human’s odor receptor genes are not functional and that they are now “evolutionary relics” that were needed and used by ancestors, but that now are useless for modern homo sapiens.

“Human smell is not the same and dogs or rodents, but it’s clearly not notably worse. If you restrict testing to traditional, volatile odors, then dogs and humans stack up pretty well against each other.”

Even modern human use more their sense of smell than it is thought. What we use it for varies in relation with other mammals. For example, a dog’s sense of smell is more sensitive to the scent of explosives; while humans’ sense of smell is more sensitive than dogs’ to the smell of amyl acetate, which is what gives bananas their distinctive odor. That may be because humans have a greater need to determine when a fruit is ripe.

All mammals, even if the olfactory bulb-body relation varies, have approximately the same number of neurons. Maybe dogs have some advantage because they devote more of their attention and behavior to investigating and analyzing smells. The ability to smell for a trained tracker dog might be hard for humans to match.

Nonetheless, Broca wasn’t entirely wrong because the repositioning of the olfactory lobe enables animals to integrate smell in mental processes, not just to sense it, but to think about it too.

Humans tend to neglect their sense of smell in many ways. McGann says that it helps people to make decisions, such as knowing if they should eat leftover food. As well, people tend to smell each other when they meet. Smell is an unexpected component of social interaction.

Partial anosmia

Unlike complete loss of smell, partial anosmia is very normal and happens to many of us from time to time. It means that some people can't smell the scent of some substances. Why and when does it happen?

All human senses operate within a certain working range, just like any other measuring tool. For example, the human eye will respond to wavelengths from about 380 to 720 nm. Out of a big variety of vibrations, from radio waves to gamma rays, humans can sense only 0.01% of them. The same situation is with audible frequencies, a standard range our ear could accept is within 20 to 20,000 Hz, the older you get, the lower the upper threshold would go, approximately it lowers to 12000 for people who reach 50 years of age.

The sense of smell in humans also has its limitations. It has been researched that newborn babies have the most sharp sense of smell and lose 50% of this ability in the first year. We gradually keep losing the sensitivity of any kind during our life.

We smell the scent of a fragrant material when its molecules physically get into our nose, which means that the fragrance substance has to be volatile enough. The receiving receptors are not big, and could accept only smaller molecules. Molecules weighing over 350 Dalton do not smell at all, at least for us.

Most often, partial anosmia is related to heavy compounds whose mass is close to the threshold of 350 Dalton (or unified atomic mass unit) Usually they possess a musky woody or ambery odor. In the case with lightweight substances, like, for example, Citral or Eugenol, they can be sensed by all healthy people. Partial anosmia is not a disease, but a phenomenon that could happen to perfumers, too. Sometimes, even if a pure substance, due to its mass, couldn't be detected by our sense of smell, we could be possibly able to smell it in a mixture with other ingredients.

The weight of a compound is one cause of partial anosmia, which is not the only one. Sometimes we do not smell fragrances because we adapt or get tired of them.

Anosmia due to adaptation

Adaptation is when people perceive odors as a background without paying attention to them. Often we are not aware of the smell of the room where we spend much time or the odor of our own body. The process of smell is a complex action: first, the substance hits the nasal epithelium, its interaction with our receptors causes an electrical signal which goes to our brain. The brain processes the received signal and compares it with familiar smells (we unconsciously collect our index of smells during the whole life). After that, our brain concludes whether the smell is of any interest or not.

On the biological level, "the most interesting" smell to us is the smell of food, or danger. If there is no danger or food in the smell, the brain loses its interest in it and switches to something more important. Recently, results of one research project have been published: two focus groups were offered to smell the same material with a neutral odor. The first group was told they were smelling a perfume, another – a toxic solvent. The process of adaptation to the odor in the second group was much slower.

Odor fatigue

Odor fatigue occurs on the receptor level. A molecule of the substance causes an electric signal only once, when it gets into the nose and transforms receptors' configuration. Therefore, over time, there comes a moment when all receptors are occupied, no signals are sent to the brain and we stop smelling the scent. You may compare it to frog's vision, it sees only moving objects. If we smell the same odor for a long time, we stop sensing it.
If you want to enjoy your favorite perfume, it is best to wear it only from time to time. Do not block your receptors with it, otherwise you will not smell it after few seconds after applying.

The same situation happens to many of us, when we step into a perfume store. Shop assistants spray perfumes into the air, in such a polluted atmosphere, the nose gets tired and we are not able to give a perfume justice. Perfume stores are not the best place to smell perfumes. It is much better to spray perfume on a blotter and go outside to smell it in the fresh air.
Or, better yet, try and smell blotters or samples in a relaxed atmosphere at home. It would be better and healthier to spray a perfume once and on the blotter from a close distance.

Sometimes our receptors, already tired of one substance, lose sensitivity to other, usually, similar scents. It is called cross-adaptation. For example, benzaldehyde lowers your sensitivity to acetophenone and nitrobenzene, they all have an expressed almond aspect.

This characteristic of our sense of smell, sometimes is used in a popular method of recognizing fragrant parts of the perfume composition. You can block the leading note by smelling it individually for a long time. Blocking it you get an ability to smell the rest of the fragrance much more clearly. This method was uses to analyze perfumes before chromatography and other technological tools were invented.

Another thing to be aware of while smelling a perfume, is ethanol, a solvent which is used in a majority of modern perfumes. It readily blocks your receptors for a couple of minutes. It would be wise to let it fly away before you start smelling a perfume.

Incidence of (permanent) anosmia

Studies done in the US and Europe have suggested that around 5% of the population have anosmia. Not one person's experience is exactly the same as another's—the sense of smell affects us in complex ways, as does its loss. It can be hugely damaging to some people, who feel an emotional loss that impacts on their enjoyment of life, their relationships, and the way in which they connect with the world.
Because loss of smell adversely affects the way food tastes, it can cause unwanted weight loss, vitamin deficiency, and malnutrition if left untreated.
Anosmia can also greatly decrease your quality of life, leading to depression.
Anosmia can be temporary or permanent. This condition has multiple causes, including COVID-19, allergies, and head trauma.

There are at-home treatments, such as smell training, which can help retrain your brain to recognize smells. Over -the-counter and medical treatments can also help.

Disturbances of the sense of smell often accompany its loss. Parosmia is used to describe a distorted sense of smell, when many things smell unpleasant. Imagine anything you smell being revolting to the point of making you feel sick, with the flavor of every meal being repulsive. I have spoken to people who have struggled to eat due to most foods making them nauseous. Phantosmia literally means "phantom smells"—people can smell real odors when they're not actually there, such as a strong smell of garlic.

To cure anosmia: smelling training

There are people who lost their sense of smell for a long time. It turns out that this happens quite often, and there are tools that allow you to systematically and successfully work on restoring your sense of smell.

Olfactory training is useful not only for those suffering from anosmia or hyposmia (incomplete loss of smell), but also for healthy people with a normal sense of smell, especially children, as it helps to develop and train the sense of smell.

Some quotes from Ron Winnegrad, the director of the perfume school IFF:

“Smell includes not only the perception of smells, but also the associated memories and emotions. You need to train your sense of smell all the time, focusing on the surrounding smells. To develop any skill – in sports, dancing, playing music, smelling – constant repetition is a necessity. This is a learning process, not a result. Try to be better today than last week.

"While eating: To improve your sense of smell, consciously smell whatever you eat; before you eat anything, first let your nose smell the food.

"When shopping: When you go shopping for groceries, clothes, or whatever, grab the item and consciously focus on its scent.

"When walking: Smell the air around you and everything that surrounds you, consciously focusing on smells. Every place and district has its own smell. Don't lose sight of the differences.

"It all comes down to practice. The point is that no matter how good you are at something, only practice will keep your skills perfect."

In smell training, the patient smells a series of four strong odors that can be found in one’s home, or in the form of essential oils. Each scent is gently sniffed for 20 seconds. This process is repeated three times daily for 6 weeks. Long-term commitment is typically required to see improvement.

Smell training may be most effective if you work on the same four odors each day, rather than alternating. It’s also recommended that you concentrate on the scent fully, giving it your full attention, for the entire 20 seconds.

To try smell training, try these scents:

• ground coffee
• rose
• citrus
• eucalyptus
• vanilla
• clove
• mint

During smell training, you may experience odd aromas that don’t jive with what you should be smelling. This includes foul odors such as burning rubber or bodily waste. This is known as parosmia. Parosmia can last for several weeks or longer but is usually temporary.

Ginger

Ginger has a distinctive, pungent scent that makes it beneficial for use in smell training. You can use powdered or raw ginger for this purpose.
Naturopathically, drinking ginger tea tames down inflammation of the nasal airways, while reducing excess mucus formations that block nasal passages, causing loss of smell.
To try ginger tea for anosmia, try using readymade ginger teabags. You can also make tea from raw ginger.

Saline irrigation

If you lost your sense of smell due to allergies or sinus congestion, a saltwater wash may help. This remedy flushes out allergens and mucus from the nasal cavity. The easiest way to do it, is to use a dedicated netipot to be filled with a saline water solution.
see for instructions: https://www.pasioonline.com/how-to-prevent-getting-sick-from-the-flu/

Zinc is essential for our sense of smell and taste.

Zinc is needed for the generation of neurotransmitters for the senses, including taste and smell, and also for hormones and digestion, and for healing and growth.
Zinc helps stem cells replicate used, aged or damaged receptor cells in the nose and mouth. Most likely, a virus infection can damage too many nasal and oral cells for for zinc and stem cells to keep up, causing the loss of taste and smell.
If zinc stores are consequently depleted by injury and illness, then the person may, following recovery, suffer an ongoing loss of taste and smell, loss of appetite, picky eating, and over-eating.
Anorexia and bulimia are closely associated with the hormone and growth surges of puberty and a history of a diet that is low in zinc.

It is worth noting that physical activity is an enormous drain on zinc stores, and athletes therefore have a greater need for zinc and other minerals than most people. This is why athletes may sometimes be more prone to the loss of taste and smell following corona virus infections such as COVID.
Is it the spike, or is it the virus, or is it both?
The main culprit for the loss of taste and smell is not the virus, although it is important, but the spike protein, which is like snake venom and extremely inflammatory. We, therefore are best to consider the mRNA vaccine, which instructs a person's cells to manufacture spike protein for may months, and the virus as being similarly damaging.
Because the viral infection may cause the manufacture of spike protein for only a matter of a week or two, the vaccine is far worse, especially when administered repeatedly as a "booster".

Zinc, the immune-booster

Zinc can help reduce the duration and severity of symptoms associated with the common cold, which often includes a loss of taste and smell. Zinc has been found to inhibit the replication of respiratory viruses, including corona-viruses, and may help to boost the immune response against these infections.

In addition to its antiviral properties, zinc is also involved in the production of mucus, which is essential for maintaining a healthy respiratory system. Adequate mucus production helps to trap and remove viruses and other foreign particles, preventing them from reaching the olfactory receptors and causing damage.

Do NOT take high doses of Zinc long-term. Why? Zinc, iron and copper form a triangle. Change one and you change the others. If you are a woman with heavy monthly cycles, you may already be borderline iron anemic. Zinc can bind iron. It’s OK to take high zinc at first sign you are ill. Don’t take iron during this time.

Men need more zinc than women in general as the prostate uses a lot of zinc. And men seldom have low iron as they don’t bleed.

Women can safely take 15 mg. Zinc daily long-term. If you are exposed or become ill, increase to 25 – 50 mg. daily with food.
After 2 weeks on the higher dose, if recovering well, go back to 15 – 20 mg. daily for a few months.
If not recovering well, stay at 40-50mg for another month and re-evaluate. Remember that zinc is essential for immune function too.
Children should take half the dose and young children even less.

Adult men can safely take 30 – 50 mg zinc regularly long-term. If ill or suspecting exposure, increase for 2 weeks to 75-100mg before dropping back.
Do NOT take 100 mg. Zinc long-term, especially if you are an athlete or heavy exerciser who tend to be low on iron.

Zinc is but one member of a powerful team of nutrients

While zinc supplementation may be beneficial, it should not be seen as a standalone treatment. Zinc should be taken as part of a nutrient-dense diet. Excessive zinc intake can have adverse effects on the body, and it is important to follow recommended dosage guidelines, and in conjunction with companion nutrients, of which there are many.

Zinc supports repairing damage to the smell and taste receptors, as might other nutrients such as copper, iron, manganese, selenium, acetyl-l-carnitine, and taurine.

Conclusion

Human sense of smell is as good as many mammals, debunking the myth of a poor human olfactory ability.
Partial anosmia is common, due to factors like molecular size, adaptation, and odor fatigue.
About 5% of people experience anosmia, impacting life quality significantly.
Treatments include:
Smell training: regular sniffing of distinct odors to retrain the sense of smell.
Natural methods: Using ginger for its anti-inflammatory effects, saline irrigation for clearing nasal passages.
Zinc: vital for regenerating smell receptors but should be managed to prevent nutrient imbalance.