Medical experts are issuing a stark warning that a poor sense of smell could be a crucial early indicator for a host of serious diseases, and they are urging the health service to adopt it as a routine screening factor.
The Overlooked Warning Sign
In a major international review published in the journal Clinical Otolaryngology, researchers from the UK, US, and Germany argue that olfactory disorders have been largely ignored by doctors. This is despite the condition affecting an estimated 20% of the general population, with rates rising in adults over 60 and among men.
The team highlighted that smell loss is more common than profound hearing loss or blindness. They point to growing evidence linking it to over 130 neurological, physical, and genetic disorders. The leading cause is chronic rhinosinusitis (CRS), an inflammation of the sinuses often associated with asthma, allergies, or cystic fibrosis.
While a temporary loss of smell is familiar with colds and flu, studies show it is eight to ten times more prevalent in Covid-19 patients. However, the researchers stress that persistent smell loss can be a red flag for far more serious, long-term conditions.
A Harbinger of Neurological and Heart Disease
Emerging research suggests a declining sense of smell can serve as an early warning for several debilitating illnesses. A recent study in Nature Communications indicated it could be one of the earliest signs of dementia, potentially because harmful proteins first accumulate in the brain's smell-processing region.
The review also notes that in 90% of Parkinson's disease cases, smell loss appears before traditional motor symptoms—sometimes as early as five years prior. Perhaps most worryingly, new evidence links a poor sense of smell to an increased risk of stroke and heart failure in otherwise healthy adults.
Broader Impacts on Safety and Wellbeing
Beyond disease prediction, a reduced sense of smell poses direct risks to daily safety and mental health. Research shows many affected individuals worry about their inability to detect gas leaks, fire, or spoiled food, raising the risk of accidents and food poisoning.
Furthermore, the condition is associated with higher rates of depression, anxiety, social isolation, and eating disorders. There is also growing evidence that people with smell loss tend to have poorer diets, opting for less varied, more calorific foods high in fat and sugar.
A Call for Action and Awareness
In light of this compelling evidence, the expert coalition—including academics from the University of East Anglia, Technical University Dresden, and University College London—is calling for systemic change. They recommend the development of public health campaigns, professional training for GPs, and the introduction of routine smell screening to tackle healthcare inequalities.
'We recommend developing smell health education programmes and awareness campaigns, introducing smell screening and developing and implementing smell health policies across sectors of society,' the authors concluded in their paper.
