[Perception of taste and smell in normal and pathological aging: an update]

The physiological and pathological aging on sense organs is widely studied in the visual and hearing modalities. By contrast, taste and smell changes are widely overlooked. These symptoms are rarely evoked in the elderly and often neglected in clinical practice. Studies in this population are rare and show contradictory results. In this update, we describe the perception of taste and smell in aging. In a first part, we present studies about the aging of smell and taste senses. While taste is remarkably spared during aging, olfaction decreases dramatically since 5th decade of life, frequently resulting in anosmia after 90 years. Numerous causes are evoked: acute conditions (mouth health, medications…) and chronic diseases frequently observed during aging (Alzheimer or Parkinson's diseases) may be responsible of such decline. In the last part, we approach the consequences on geriatric practice, as regards the nutrition of old subjects, including a cognitive approach regarding to perceptual functions and environmental determinants of nutrition. Taste and olfaction disorders should be considered as a geriatric syndrome that geriatricians have to be aware in clinical practice.