The effects of ageing on smell The sense of smell is often taken for granted, that is until it deteriorates. As we get older, our olfactory function declines. Not only do we lose our sense of smell, we lose our ability to discriminate between smells.
Luckily all aromas get less over time thanks to a weakening concentration of scent molecules. Smells 'disappear' when the aroma molecules disperse in the air to a concentration below your detection threshold.
Some loss of taste and smell is natural with aging, especially after age 60.
Causes of lost or changed sense of smell
Changes in sense of smell are most often caused by: a cold or flu. sinusitis (sinus infection) an allergy, like hay fever.
According to Tajudeen, smell loss is most commonly caused by nasal and sinus inflammation. This inflammation can occur due to sinusitis, polyps in the nose and even allergies. It can act as a barrier for smell molecules to enter your nose, meaning you can't physically pick up the smell.
Olfactory retraining is the process of retraining your nose to smell. It involves smelling strong scents (citrus, cloves, eucalyptus) every day while thinking about what they smell like to try to help reform normal responses to your nose and brain. Research has shown it can improve parosmia in long COVID patients.
Smell strong-smelling odours (like the ones you briefly eliminated), such as ground coffee, spices, mint, and eucalyptus. The molecules in essential oils taken from plants can also be used for olfactory training.
Therefore, perhaps a lack of vitamin D leads to neurological decline of the central and peripheral nervous system, including the cranial nerves, leading to reduced olfaction. The issue of reduced olfaction with vitamin D deficiency is not just an issue of mechanistic interest.
Another tactic is to choose four or five scents you are fond of and really take a good sniff of each one. Doing this will stimulate olfactory (smell) receptors in your nose. It can also be helpful to associate certain pleasant aromas with equally pleasing feelings so you'll be more likely to recall different scents.
In fact, according to research published in Nature, your nose can detect about one trillion smells! But your own underarms could reek and you might not be able to tell: Humans are prone to what scientists call olfactory fatigue; our sense of smell just gets plain tired out by familiar odors and stops detecting them.
Not only do we lose our sense of smell, we lose our ability to discriminate between smells. It has been reported that more than 75% of people over the age of 80 years have evidence of major olfactory impairment, and that olfaction declines considerably after the seventh decade.
Our sense of smell in responsible for about 80% of what we taste. Without our sense of smell, our sense of taste is limited to only five distinct sensations: sweet, salty, sour, bitter and the newly discovered “umami” or savory sensation.
Inflammation—Swelling of the tongue can cause the taste pores on it to close. This can sometimes indicate vitamin deficiencies, such as lack of B12. Vitamin or mineral deficiencies—Deficiencies in the B vitamins, especially B12, as well as certain minerals like zinc have been associated with loss of taste.
Your sense of smell can also diminish, especially after age 70. This may be related to a loss of nerve endings and less mucus production in the nose. Mucus helps odors stay in the nose long enough to be detected by the nerve endings. It also helps clear odors from the nerve endings.
To put it simply, fragrance fatigue is your body's natural desensitization to the same smells over time. Your body generally desensitizes itself to all stimulation over time to prevent overloading your nervous system so you can respond to new stimulation more easily.
Smell adaptation
This is called 'adaptation'. Loss in smell sensitivity is only temporary and is particular to that 'over-smelled' odour. Recovering from adaptation depends on the individual but can range from a few seconds to a couple of minutes.
When you're congested, it can interfere with the ability to detect scents properly. This can result in a reduced sense of smell, which in turn, affects our sense of taste. Loss of taste is a common symptom experienced by people who are suffering from nasal congestion.
Loss of smell can be caused by: Medicines that change or decrease the ability to detect odors, such as amphetamines, estrogen, naphazoline, trifluoperazine, long-term use of nasal decongestants, reserpine, and possibly zinc-based products.
Vitamin B12 deficiency can also cause symptoms that affect your brain and nervous system (neurological symptoms), including: numbness. muscle weakness. psychological problems, which can range from mild depression or anxiety, to confusion and dementia.
Those who do not get a sufficient amount of vitamin D or are vitamin D deficient lose their sense of smell and taste with age. They might not recognise the sign early as they progress slowly and is impaired with age.
A traditional olfactory training protocol uses four specific scents: rose, lemon, eucalyptus, and clove.
Conclusion: The use of fluticasone nasal spray and triamcinolone paste had immensely influenced the basic senses such as smell and taste. Our study showed that olfactory and taste function significantly improved in patients with COVID-19.
“We found that probably 80% of those patients who have a loss or distortion of their sense of smell will recover that sense about one to three months after the COVID-19 infection has resolved. But that still leaves up to 20% of people who have an ongoing disturbance in their sense of smell.”