Taste in mild cognitive impairment and Alzheimer’s disease

Abstract

In this prospective study we investigated the quantitative and qualitative taste function of patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). 29 healthy, elderly subjects, 29 MCI and 30 AD patients were tested using a validated taste test, the "taste strips". Additionally, odor identification, odor discrimination, odor threshold, the mini-mental state examination (MMSE) and Apo E epsilon 4 status were examined. Regarding taste, there was a significant reduction of total taste scores and also the score for individual tastes on either side of the tongue between controls and MCI/AD patients. There was no significant difference in the taste scores between MCI and AD patients. A taste test may be a useful procedure for differentiating between healthy subjects and patients with MCI/AD in a clinical context. For diagnosing MCI versus AD, further tests such as smell test, MMSE, Apo E epsilon 4 status, FDG-PET and MRI appear to be useful.

Assessment of Preference for Edible and Leisure Items in Individuals With Dementia

“…A more likely possibility is that the general lack of preference for food shown by our participants was related to their clinical condition. Specific food preferences are dependent on sensory capacity (Booth, 1985), which commonly decays in advanced age and is much worsened in individuals with cognitive impairment and dementia (Steinbach et al, 2010). Thus, decreased ability to discriminate taste differences may weaken food preferences, although whether food per se is a less effective reinforcer for patients with dementia cannot be determined from the present data.…”

Smell identification function and Alzheimerʼs disease

“…Almost uniformly, participants did not report decline in either olfactory detection or identification, prediction of olfactory identification scores from subjective reports of olfactory function was poor, and awareness of olfactory decline bore no relationship to the likelihood of amnestic MCI patients progressing to Alzheimer's disease by the 12-month review [48]. Another study that looked at both olfactory and gustatory functions found poorer subjective olfactory/gustatory scores in Alzheimer's disease compared to MCI, implicating pathological pattern of hippocampal-parietal memory impairment [50].…”

Systems-Level G Protein-Coupled Receptor Therapy Across a Neurodegenerative Continuum by the GLP-1 Receptor System

“…Olfactory impairment has been shown to be predictive of conversion from mild cognitive impairment to AD with a higher than 80% sensitivity (66). With respect to it has also been demonstrated that both cognitively impaired and AD patients present a significant reduction of total taste scores and also individual taste scores on either side of the tongue (67). As sensory modalities are currently further investigated in AD, it appears that these systems may eventually serve as potential “therapeutic gateways” into the psychosocial and physiological alterations in AD (66).…”