The diagnosis of Alzheimer's disease is often a difficult process requiring thorough examination as well as the use of a number of expensive and complicated tests that may not always be available. However, recent research out of the University of Florida has determined that a simple and potentially powerful test may be available at your local grocery store.
Alzheimer's disease (AD) is a devastating neurodegenerative disease that accounts for 50-80% of dementia cases. Often, in the early stages of the disease the portions of the brain responsible for smell are affected, resulting in a decrease in odor detection sensitivity. The key to this test lies in the observation that this degradation is asymmetrical?that is, the left side deteriorates sooner than the right side. Using "14 g of peanut butter" (chosen because it's a pure odorant), researchers found that in cases of probable AD, the distance of detection varied significantly between the left and right nostrils. This difference was specific to AD not seen for other causes of dementia.
So can we expect hospitals and clinics to begin auctioning off costly imaging systems and stocking up on peanut butter instead (a question I never thought I?d ask!)? This seems unlikely. As one KOL noted, the olfactory test described above is not very helpful in gathering information about the cause of the disease because it doesn?t target any pathological hallmarks of Alzheimer's such as beta amyloid plaque buildup or tangles of the protein tau. It's also currently unknown how well the results of this test will correlate to established diagnostic tests that do target a particular neuropathology of AD, and longitudinal follow-up will be needed to determine how effective it is.
This research is in its early stages and requires confirmation and further study. Nonetheless, while peanut butter might not be the key to developing a disease-modifying therapy, this simple, specific, inexpensive test has significant potential in the early diagnosis of AD and could potentially impact the diagnostic process for this disease. At the very least, it seems clear that peanut butter should no longer be typecast as just one half of a sandwich.