【Objective】
This study aims to clarify the trends in olfactory function associated with “green tea” in elderly individuals using day services, categorized by cognitive function.
【Methods】
115 participants were divided into three groups based on the Mini-Mental State Examination-Japanese: 46 normal, 33 mild cognitive impairment(MCI), and 36 cognitive decline groups. Olfactory identification(OE), self-awareness of 12 odorants related to OE from a daily life scent questionnaire, and depression(GDS) were compared using χ2 tests, logistic regression analysis, Spearman’s rank correlation coefficient, and Kruskal-Wallis tests.
【Results】
The cognitive decline group showed significantly lower scores in OE total points, correct rates, and self-awareness rates of 12 odorants compared to the normal and MCI groups. In particular, the cognitive decline group had a higher number of incorrect answers than correct ones, especially for orange(linalool) and rose (geraniol), with the odds ratio for orange being notably high. MMSE-J showed slight correlations with the olfactory components of perfume(linalool, geraniol) and orange.
【Conclusion】
The normal group showed olfactory decline related to “green tea” scent with aging. The MCI group had slightly reduced cognitive function but resembled the normal group. Further research is needed on the method and effects in the MCI group, as no confirmed link was found between “green tea” aroma and cognitive function. In contrast, the cognitive decline group showed significant olfactory decline linked to “green tea,” highlighting the need for further studies on olfactory stimulation effects.
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