The Psychological Moderating Effect of Olfactory Function on Cognitive Function Changes According to Age in Older People

Abstract

We conducted this study to verify the regulatory role of olfactory function in age-related cognitive function changes in older people. This study included 140 subjects aged 65 years or older living in region C, South Korea. We conducted an olfactory test and a questionnaire survey. Age significantly affected cognitive function (F=99.115, p<.001), and the explanatory power was 41.4%. The explanatory power with the addition of the olfactory function was significantly increased to 60.8% (F=108.604, p<.001). There was a moderating effect of olfactory function (F=85.135, p<.001), indicating 64.5% explanatory power. Analysis of the conditional effect of olfactory function on cognitive function according to age showed that age had a negative effect on cognitive function when olfactory function is impaired (-1 SD; B=-0.24, se=0.05, t=-4.64, p<.001 and average; B=-0.12, se=0.04, t=-2.69, p=.008). However, age did not appear to have a significant effect on the cognitive function when olfactory function is not impaired (+1 SD; B=0.01, se=0.06, t =0.18, p=.860). We found that olfactory function regulates cognitive function in older people. Therefore, we suggest an intervention program to improve olfactory functions in older people.