How Our Sense of Smell Protects Us from Everyday Hazards

When you think about it, so much of the way we experience the world is through the nose. The aroma of a favourite food, a whiff of a popular perfume or after shave, and the smell of crackling wood in the firepit all enhance our lives in a way we may take for granted. Sensory cells within the nose transmit olfactory, or smell, messages to the brain. Over time, these smell receptors, like those for taste, stop regenerating as rapidly, according to VeryWell Health.

Diseases like stroke, epilepsy and various medications can also affect how smell is perceived by the brain. How well we smell also plays a large role in what we taste. A dwindling sense of smell, referred to by medical practitioners as anosmia, likely also accounts for most changes in taste with age. A University of Ottawa and Sodexo study found sense of smell can diminish with age and impact the ability to taste.

The risks:

People who have total or partial loss of the sense of smell are almost twice as likely to have some kinds of accidents or incidents than people who have normal smell (or olfactory) function, the National Institutes of Health reports. Researchers from Virginia Commonwealth University Medical Center reviewed medical records for the past twenty years and discovered several important danger areas:

  • cooking-related accidents
  • exposure to an undetected fire or gas leak
  • eating or drinking spoiled foods or toxic substances by individuals with this sensory impairment

Some studies have suggested that loss of smell could be an early sign of a neurodegenerative disease, such as Alzheimer’s or Parkinson’s disease. However, a recent study of 1,430 people (average age about 80) showed that 76 percent of people with anosmia had normal cognitive function at the study’s end, according to Harvard Medical School.

Practical tips:

“To improve smell, maintain regular exercise, avoid excess drinking, stay away from strong fumes, challenge the nose by familiar smells, and make sure smoke and CO2 detectors are working,” said Lakelyn Hogan, Home Instead Senior Care® Gerontologist and Caregiver Advocate.

According to the New York Otolaryngology Group, half of all anosmia cases can be treated and reversed with nonsurgical therapies. Symptoms and the effects of loss of sense of smell can be reduced in most other instances with coping strategies.

Hope on the horizon:

Researchers at Massachusetts Eye and Ear have induced a sense of smell in humans by using electrodes in the nose to stimulate nerves in the olfactory bulb, a structure in the brain where smell information from the nose is processed and sent to deeper regions of brain. Reporting online today in International Forum of Allergy & Rhinology, the research team describes their results, which provide a proof of concept for efforts to develop implant technology to return the sense of smell to those who have lost it.

Who can help:

An ENT doctor or neurologist could help. To test smell, doctors may hold common fragrant substances (such as soap, a vanilla bean, coffee, and cloves) under the person’s nose, one nostril at a time, according to Merck. The person is then asked to identify the smell. If there is no clear cause of anosmia, computed tomography (CT) or magnetic resonance imaging (MRI) of the head (including the sinuses) is done to look for structural abnormalities (such as a tumor, an abscess or a fracture).

Help at home also could keep someone with a compromised sense of smell safe from the hazards that could go undetected.

Discover the risks associated with another sensory loss – touch – in the elderly.

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