A Simple Smell Test Could Offer Early Warning for Alzheimer’s
Difficulty recognizing familiar smells,like the scent of soap during a shower,may be an early indicator of cognitive decline,potentially years before noticeable symptoms appear. This is according to research led by Dr. Davangere Devanand, chair of psychiatry and neurology at Columbia University in New york. The issue isn’t simply a loss of smell,but a deficit in the brain areas responsible for memory and associating sensations with memories – a precursor to the cognitive problems associated with Alzheimer’s disease and other forms of dementia,often initially mistaken for fatigue or stress.
Dr. Devanand’s study, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, utilized a brief olfactory test to assess 647 volunteers without diagnosed dementia, participants in the ongoing Mayo Clinic Study of aging. Participants were followed for an average of 8.1 years.
The Brief Smell Identification Test (BSIT) presents twelve common scents – including soap, leather, lilac, smoke, gas, rose, cherry, cloves, strawberry, menthol, pineapple, and lemon – and asks participants to identify each from a multiple-choice selection of four options.
The resulting score, ranging from 0 to 12 (adjusted downwards for incorrect answers), indicates the health of olfactory function. A score of 9 or higher suggests an intact sense of smell.Scores between 8 and 3 indicate impairment, while a score below 3 signifies anosmia (loss of smell).
Researchers then correlated BSIT results with cognitive assessments, such as the Blessed Data Memory Concentration Test, and data from advanced imaging techniques like PET amyloid scans and magnetic resonance imaging. This cross-referencing validated the accuracy of the BSIT.
The test proved remarkably predictive, successfully identifying 102 cases of future cognitive decline and 34 cases of dementia. “Using a simple smell test can predict cognitive decline,” explains Dr.Devanand, highlighting the potential for this accessible and affordable method to provide early detection of cognitive impairment. The BSIT offers a less invasive and more economical alternative to more complex and costly diagnostic procedures, like blood tests, cerebrospinal fluid analysis, and brain imaging, for initial screening and risk assessment.
