Inability to Smell Peppermint Is Related to Cognitive Decline: A Prospective Community-Based Study

Neuroepidemiology. 2020;54(3):258-264. doi: 10.1159/000505485. Epub 2020 Jan 14.

Abstract

Background: A few studies have demonstrated the association of poorer olfactory identification (OI) with poorer cognition in population-based cohorts. None of them considered the outcome associated with the inability to smell a certain odor.

Objective: To verify the hypothesis that at least one specific odor is associated with incident cognitive decline among older adults.

Methods: In the Shanghai Aging Study, a sub-cohort of 948 dementia-free participants who had baseline OI measurements were prospectively followed for 5 years.

Results: An inability to smell peppermint (β = -0.44, p < 0.001), rose (β = -0.14, p = 0.040), or coffee (β = -0.37, p = 0.002) was inversely related to the annual rate of change in the Mini Mental State Examination score, and an inability to smell peppermint was associated with a higher risk for incident dementia (hazard ratio 2.67, 95% CI 1.44-4.96) after adjustment for confounders.

Conclusion: Our study suggests that some odors, especially peppermint, might be considered as a potential predictor for dementia in older populations.

Keywords: Cognitive function; Community-based study; Dementia; Elderly; Odor; Olfactory identification; Prospective study.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • China
  • Coffee
  • Cognitive Dysfunction / complications
  • Cognitive Dysfunction / diagnosis*
  • Dementia / complications
  • Dementia / diagnosis*
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Mental Status and Dementia Tests* / statistics & numerical data
  • Mentha piperita*
  • Middle Aged
  • Olfaction Disorders / diagnosis*
  • Olfaction Disorders / etiology
  • Risk
  • Rosa

Substances

  • Coffee