How well you smell as you age may reveal important clues about your cognitive health. A study published in the Journal of Neurology led by Dr. D.P. Devanand showed that if your ability to identify various odours starts to decline, it is a good predictor of impending cognitive decline. A similar study at the University of Florida Health produced the same finding. Graduate student Jennifer Stamps explained that the first cranial nerve, which is frequently affected as cognitive ability declines, is also associated with the sense of smell.
Using roughly one tablespoon of peanut butter to test the sense of smell, Stamps measured how close the peanut butter had to be to the subject’s nose in order to be detected. Curiously, there was a demonstrated difference in the ability of the left nostril to smell the peanut butter compared to the ability of the right nostril in those diagnosed with the early stages of Alzheimer’s Disease while those whose diagnosis did not show Alzheimer’s Disease demonstrated no difference in their nostril’s detection abilities. In subjects diagnosed with the early stages of Alzheimer’s Disease the peanut butter needed to be an average of 10 cm closer to the left nostril than the right nostril.