The expression the nose knows appears to have more relevance as we age according to this study of German seniors.
In a large population-based study of randomly selected participants in Germany, researchers found that participants aged 65-74 years with olfactory dysfunction showed impaired cognitive performance. Interestingly, this strong association was not present in younger (55-64 years) or older (75-86 years) participants. Additionally, the effect was more present in women than men.
In neurodegenerative diseases like Parkinson’s and Alzheimer’s disease (AD), olfactory function is diminished. Further, olfactory dysfunction precedes the onset of cognitive impairment within AD, which highlights its potential as biomarker for early, preclinical diagnosis. Several studies suggest that olfactory dysfunction predicts progression from normal cognitive functioning to mild cognitive impairment and AD. There is little evidence for this association concerning different age stages and gender differences. Continue reading