n a small pilot study of patients displaying signs of cognitive decline, researchers at the McKnight Brain Institute Center for Smell and Taste and the University of Florida (UF) found that peanut butter can help identify those with Alzheimer’s disease (AD), a neurodegenerative disorder often accompanied by a loss of smell.
Working with 18 patients with probable AD, 24 with mild cognitive impairment, 26 with other causes of dementia, and 26 matched controls, graduate student Jennifer Stamps and her UF advisor Kenneth Heilman measured the distance from the nose at which a patient (whose eyes were closed) could smell a tablespoon of peanut butter. They ran the test one nostril at a time and found that early-stage AD patients had dramatically different smell sensitivity between the right and left nostrils, with the left regularly being more severely impaired. The other patients tested displayed no such difference in smell sensitivity.