Researchers at the University of Florida have discovered that sniffing peanut butter can often be a good indicator of the onset of Alzheimer's Disease.
"Knowing that patients in cognitive decline often lose their sense of smell first, the researchers had patients sniff a dollop of peanut butter with each nostril separately. They used a ruler to measure the point at which people detected the odor (and to keep the other nostril closed).
The weird result: People with a confirmed diagnosis of early-stage Alzheimer's could smell it fine with their right nostril, but not their left, say the UF scientists. Generally speaking, the right nostril picked up on it 10cm before the left one. Also of note: The left-right difference is specific to Alzheimer's, and doesn't apply to other forms of dementia."
After reading this, tell me you're not heading for the cupboard to find a jar of peanut butter and try this yourself.