Here’s how they conducted the test. The researchers asked each person to close their eyes, their mouth and one nostril. They opened a small container of peanut butter and moved progressively closer until the person could smell it. After measuring that distance, they waited 90 seconds and repeated the process with the other nostril.
In those with probable Alzheimer’s disease, the researchers had to move the peanut butter container an average of 10 centimeters closer to the left nostril than to the right nostril.
“This is a significant part of this study,” notes Dylan Wint, MD, a specialist in degenerative brain diseases who commented on the research. “There is a lot of research showing Alzheimer-related brain shrinkage starting on the left side of the brain, which is where the temporal lobe degenerates first.”