There’s something comforting about the smell of a fresh peanut butter sandwich — more comforting than you might realize.

A small study at the University of Florida indicates that people in early stages of Alzheimer’s disease were better able to smell peanut butter in the right nostril than in the left.

Conversely, people who do not experience that difference do not have Alzheimer’s. That’s comforting news (although they could have other kinds of dementia).

Scientists at the University of Florida’s McKnight Brain Institute Center for Smell and Taste came to these early conclusions using only some peanut butter, a ruler and 24 patients.

Testing one nostril at a time, they measured how close the peanut butter needed to be for subjects to smell it. Blindfolded patients diagnosed in early stages of Alzheimer’s needed the peanut butter to be 10 centimeters closer to their left nostril than their right in order to smell it. The ability to smell is associated with the first cranial nerve and can be one of the first things affected in dementia.

The test, published in the Journal of the Neurological Sciences, needs further study to determine if it can be used to predict which patients will get Alzheimer’s.

But scientists at the University of Florida say it can be used to confirm diagnoses.

Meanwhile, don’t let the science make you forget that childhood pleasure of soft sliced bread slathered with creamy (or crunchy) peanut butter.