Diseases and aging: patterns of morbidity with age; relationship between aging and age-associated diseases.

Patterns of morbidity with age can be schematically represented in three situations: 1) as a progressive illness, such as Alzheimer's disease, leading to a relatively rapid functional decline. 2) as a catastrophic event, such as a stroke or hip fracture, leading to a decline in function with improvement after rehabilitation. 3) as normal aging with gradual progressive functional decline. Results from the New Mexico Aging Process Study provide some unique insights about the consequences of the effects of aging on the nutritional status of healthy elderly people. Between 1979 and 1989, anthropometric and biochemical markers as well as dietary intakes remained relatively constant in this healthy elderly population. Thus, the aging process alone may have little or no important consequences on the nutritional status of healthy elderly individuals. However, the adaptation of pancreatic and intestinal function to undernutrition and refeeding can be perturbed in these individuals.