Loss of sense of smell has become an important sign that can reveal a range of diseases, and may even be an early indicator of serious neurological and physical illnesses, according to international experts.

 

It is estimated that olfactory disorders affect about one-fifth of the population, with higher rates among adults over 60 and among men. However, experts emphasize that the medical community has neglected these disorders despite their association with more than 130 diseases and their greater prevalence than severe hearing loss and blindness.

Chronic sinusitis is the most common cause of loss of smell, and it may result from airway obstruction due to asthma, allergies, or cystic fibrosis.

Researchers have indicated that loss of smell may be an early sign of serious illnesses such as dementia, Parkinson's disease, and heart disease. The study confirmed that loss of smell may be one of the first signs of dementia, as it indicates the accumulation of harmful proteins in the part of the brain responsible for smell. Other studies have shown that a diminished sense of smell may appear up to five years before the onset of motor difficulties associated with Parkinson's disease in up to 90% of patients.

The experts added that loss of smell is linked to an increased risk of stroke and heart failure in healthy adults, and may also contribute to household accidents and foodborne illnesses due to the inability to detect gas, fire, smoke, or spoiled food.

The review showed that people with loss of smell often suffer from eating disorders, social isolation, relationship difficulties, anxiety and depression, and tend to follow a less varied diet that is high in fat and sugar.

In light of this evidence, experts called for the inclusion of smell testing in medical practices, training of specialists in it, and the development and implementation of health and educational policies about the sense of smell in society.

The review was conducted by experts from the University of East Anglia, the Technical University of Dresden in Germany, the Monell Chemical Senses Center in the United States, the Smell Test charity, and the Department of Computer Science at University College London.

The scientific review was published in the journal Clinical Otolaryngology.