Alterations of sensory perceptions in healthy elderly subjects during fasting and refeeding. A pilot study

Sensory perception losses may contribute to age-related malnutrition by affecting food selection and consumption.

To determine the effects of a 36-hour fast followed by a 6-hour refeeding period on sensory perceptions in 7 healthy elderly subjects (65-80 years of age) and 6 healthy young subjects (18-35 years of age).

Self-perceived hunger and olfactory ratings were recorded on visual analogue scales in response to three different classes of odorant stimuli (salt, sweet and sour). Odorant stimuli were administered three times during the study, twice during the fasting period (12 and 24 h fasted) and once at the end of the re-nutrition period.

A significant difference was found between the two groups for the self-perceived hunger ratings in response to the sour stimuli. A significant difference was observed between the two groups for olfactory ratings as regards the salt and sour odorant stimuli. Among the metabolic changes associated with fasting and refeeding, blood glucose was significantly related (r(2) = 0.97, p = 0.001) to the perception of hunger in the control group subjects, but no such relationship was found for the elderly subjects (r(2) = 0.16, p = NS).

(1) Self-perceived hunger and olfactory ratings are specifically affected in healthy elderly. (2) Nutritional status can modulate sensory perceptions in elderly and young during the transition from fasting to refeeding.