In this article from the Frontiers in Psyhcology from 2014 The sense of smell plays a crucial role in our daily lives. It allows us to perceive thousands of odors, from the aroma of freshly baked bread to the scent of blooming flowers. However, as we age, our olfactory function can decline significantly. In this review, we delve into the factors that contribute to age-related olfactory loss and explore its impact on physical well-being, quality of life, and safety.
The Prevalence of Smell Loss
Cross-sectional studies reveal that smell loss is prevalent among older adults. Approximately half of the United States population between the ages of 65 and 80 experiences demonstrable smell loss, and this percentage increases to approximately three-quarters in those over the age of 80. Such dysfunction affects various aspects of life, including:
- Physical Well-Being: Smell loss influences nutrition and appetite, as it impacts the enjoyment of food.
- Safety: A disproportionate number of elderly individuals die in accidents related to gas poisonings each year due to impaired smell function.
- Quality of Life: The ability to fully appreciate flavors, fragrances, and the environment is diminished.
Multiple factors contribute to the decline in olfactory function with age
- Nasal Changes: Altered nasal engorgement and an increased propensity for nasal disease affect olfactory function.
- Environmental Damage: Cumulative damage to the olfactory epithelium from viral infections and other environmental insults.
- Enzyme Decrements: Reduced mucosal metabolizing enzymes impact odor perception.
- Structural Changes: Ossification of the cribriform plate foramina and loss of receptor cell selectivity.
- Neurological Factors: Changes in neurotransmitter and neuromodulator systems, as well as the expression of aberrant proteins associated with neurodegenerative diseases.
Early Signs of Neurodegenerative Diseases
Interestingly, decreased smell function can serve as an early sign of neurodegenerative diseases such as Alzheimer’s disease and sporadic Parkinson’s disease. Researchers have established a link between olfactory dysfunction and these conditions, emphasizing the importance of assessing smell loss in clinical practice. In summary, age-related olfactory loss is a common phenomenon with significant implications for health and well-being.
