Cognitive Function and Olfactory Ability in the Elderly: An Association Analysis

Background: Olfactory impairment has been associated with cognitive decline in older adults. However, investigations into the association between cognitive function and olfactory performance remain scarce, particularly within Southeast Asian populations. This study aims to investigate the association between cognitive function and olfactory ability in the elderly population, as well as its impact on olfactory-specific quality of life using culturally adapted smell test. Methods: A cross-sectional study was conducted among 99 community-dwelling older adults aged ≥60 years. Cognitive function was evaluated using the Montreal Cognitive Assessment (MoCA), and olfactory ability was assessed using the Malaysian-adapted Sniffin’ Sticks test. The total threshold–discrimination–identification (TDI) score was used to categorize olfactory function. Olfactory-specific quality of life was measured using the validated Malay version of the short Questionnaire of Olfactory Disorders–Negative Statements (sQOD-NS). Results: Among the participants, 74 demonstrated cognitive impairment and 63 were classified as hyposmic. A significant positive correlation was observed between cognitive scores and overall olfactory performances, particularly in the discrimination subtest. Cognitive impairment was also associated with poor olfactory related quality of life. Conclusion: This cross-sectional study highlights a significant association between cognitive performance and specific domains of olfactory function, particularly odor discrimination. These findings support the potential utility of olfactory testing in cognitive screening strategies, although causal relationships cannot be inferred from this cross-sectional design.