Smell May Outlast Other Senses

About 1000 Australian males and females of all ages were tested for their ability to detect or identify a range of different odours at different concentrations, and then given an overall score for their sense of smell, or olfactory function.

The results showed that olfactory function deteriorates relatively slowly with age in those who do not smoke, take medications or have a history of nasal problems such as sinusitis.

However the ability to smell drops off much quicker in older people who were taking medications -- also an indicator of underlying health problems.

Researcher Dr Amy Johnston, from Griffith University's School of Nursing and Midwifery and the Eskitis Institute of Cell and Molecular Biology, said the study suggested that aging alone had a small detrimental effect on smell.

"However our sense of smell is vulnerable to both the direct effects of some medications and changes associated with a number of neurodegenerative illnesses. Exposure to these factors typically increases with age."

Anticholesterol and blood pressure lowering medications were amongst the common drugs known to interfere with smell. Conditions such as Parkinson's disease and Alzheimer's disease were also associated with impairment in the sense of smell, she said.

Dr Johnston said the ability to smell was an important factor in the enjoyment of food flavours.

"People who lose their sense of smell, particularly the elderly, are at risk of poor appetite and subsequent poor nutrition. Smell is also an important warning sense -- telling people when food is not fit for consumption."

Healthy women were shown to have a more sensitive sense of smell than healthy men but the gender effect was not apparent in smokers, people on medications or with a history of nasal problems.

The study was published in the journal Chemical Senses. Dr Johnston and other members of the Clinical Neurology group continue their research focusing on the impact of common medications on the sense of smell.