Age-related deficiency in the perceived strength of six odorants

Abstract

A group of 20 elderly persons (70–89 yr) and a control group of 20 young persons (18–25 yr) made magnitude estimations of five concentration levels of six odorants and of five concentration levels of a tastant, NaCl. Relative to the estimations of the salt solutions, the elderly's estimations of all six odorants were lower than those of the young. This outcome substantiates an earlier finding that, at least for one odorant (iso-amyl butyrate), old age blunts perceived odor strength more frequently and seriously than gustatory strength. The present experiment broadens the picture and leads to the conclusion that age-related hyposmia is likely to affect the perception of many, if not all, odors. The six odorants were selected on the basis of structural diversity, hedonic tone, and earlier psychophysical study of them. They include three pleasant odors (iso-amyl butyrate, benzaldehyde, and d-limonene), one foul smelling (pyridine), and two relatively neutral ones (ethyl and iso-amyl alcohol). To a first approximation age-related weaknesses to these compounds can be characterized as a constant per cent reduction of olfactory strength across concentration level. tion level.