New Peanut Butter Test May Help Diagnose Alzheimer's

Could peanut butter help diagnose Alzheimer's? According to researchers, it can. Scientists have developed a test involving a dollop of peanut butter and a ruler that could help confirm a diagnosis of early stage Alzheimer's.

The idea for this test actually came from observations in Heilman's clinic. That's when Jennifer Stamps, one of the researchers, noticed that patients were not tested for their sense of smell during diagnosis. The ability to smell is associated with the first cranial nerve and is often one of the first things to be affected by cognitive decline, which means that a smell test could help with detecting conditions such as Alzheimer's.

That's where the peanut butter comes in. A pure odorant, peanut butter is only detected by the olfactory nerve and is easy to access. In order to test whether it could be used to confirm diagnoses, though, the researchers conducted a study.

Patients were tested for their sense of smell using about one tablespoon of peanut butter and a ruler. After the patient closed their eyes, they breathed normally. The researchers then slowly inched a spoon filled with peanut butter closer and closer toward the patient's nose--one centimeter at a time. The distance was then recorded when the patient could detect the odor.

So what did they find? It turns out that the patients in the early stages of Alzheimer's disease had a dramatic difference in detecting odor between the right and left nostril. The left nostril was impaired and did not detect the smell until it was an average of 10 centimeters closer to the nose than when the right nostril had made the detection. That's not all, though; this wasn't the case in patients with other kinds of dementia. In those cases, patients had either no difference in odor detection between nostrils or the right was worse at detecting odor than the left.

"At the moment, we can use this test to confirm diagnosis," said Stamps in a news release. "But we plan to study patients with mild cognitive impairment to see if this test might be used to predict which patients are going to get Alzheimer's disease."

The new test could actually be used by clinics that don't have access to equipment or personnel for more elaborate tests. In addition, it provides researchers with a cheap, new tool to add to the arsenal of tests for detecting Alzheimer's.

The findings are published in the Journal of the Neurological Sciences.