A quantitative study of histological changes in the human parotid gland occurring with adult age.

Parotid samples from 63 'sudden death' necropsies of both sexes, aged 17-90 years, were collected after exclusions for chronic illness or medications. Advancing age was accompanied by acinar atrophy and ductal irregularities. The adipose content varied widely at all ages but, together with fibrovascular tissue, tended to increase with age. Stereological analysis demonstrated a linear reduction of acinar proportional volume amounting to 30% over the age range. Females tended to have more adipose tissue and less fibrous tissue than males. These structural age changes resemble those of other salivary glands, but unlike the latter are not accompanied by age-dependent functional impairments. This suggests a greater acinar secretory efficiency or larger secretory reserve volume in the parotid than in other glands. The frequent high levels of parotid adiposity encountered suggest this feature is not pathological nor necessarily a reliable indicator of nutritional or hormonal diseases, excluded from the present study.