Olfactory acuity and cognitive function converge in older adulthood: support for the common cause hypothesis

Area of Science:

• Neuroscience
• Gerontology
• Sensory Science

Background:

• Cognitive decline and sensory impairments (vision, hearing) are common in aging.
• Existing cognitive tests often rely on visual and auditory input, potentially confounding results.

Purpose of the Study:

• To investigate the common cause hypothesis linking olfactory acuity and cognitive function in aging.
• To explore if olfactory function serves as a biomarker for brain aging.

Main Methods:

• Structural equation modeling was used to analyze data from 98 non-demented older adults and 103 younger adults.
• Olfactory acuity and cognitive function data were assessed in both age groups.

Main Results:

• The common cause model showed a better fit for older adults' data, supporting the hypothesis.
• Age-related changes uniquely influenced cognitive and sensory variables beyond shared factors.
• Olfactory function demonstrated a correlation with cognitive function in older adults.

Conclusions:

• Olfactory function may be a valid indicator of the aging brain's integrity in older adults.
• Sensory and cognitive declines in aging may share underlying common causes.
• Further research into olfactory biomarkers for cognitive aging is warranted.