Aging continues throughout the life span
The changes associated \vith aging generally begin as soon as the gro\vth and development of a particular body subsystem are completed. In other words, there is no plateau of optimal functioning during the middle years. People do not stay "in their prime" for 20 or 30 years and then suddenly age. Instead, loss of function is uniform into the eighth and ninth decades. Elderly people are losing function at the same rate as younger people-an 80 year old person is aging at the same rate as a 30 year old; he has simply aged longer. 10
20 Nutrition for older persons
People tend to differ more as they grow older. Babies resemble each other more in behavior and physical growth than do adolescents. The elderly show still more individual variations, as Dr. Swansonll has pointed out:
A person at 70 is an historical record of all that has happened to him-his injuries, infections, nutritional imbalances, fatigues, and emotional upsets. Old people, therefore, differ from each other much more than do younger folk. All this needs to be considered in food planning for any older person. Each one is an individual, quite unlike anyone else.
Individuals age at different rates
Chronological age is a poor predictor of functional ability. Some 80 year olds function as well as the average 40 year old, and some 40 year olds perform like the average 80 year old.IO
Age-related changes occur in practically every part of the body 6.to.12-14
The bones decrease in density. Lean body mass tends to be lost, whereas adipose tissue and connective tissue generally increase. The heart may pump blood less efficiently. Blood flow may be reduced because of atherosclerotic deposits in the blood vessels and less elastic walls. The rate of renal blood flow is often reduced, and the kidneys are less efficient in removing waste products from the blood. Nerve signals are transmitted at slower speed. The lenses ofthe eyes lose the ability to focus a t near distances, and elderly people usually need brigh ter light to see without glasses than do young adults. Hearing loss is common, especially for high tones. Smell and taste may become less acute,15-li and loss of teeth may make che\ving difficult. Digestion may become slightly impaired as a resul t of decreased hydrochloric acid secretion by the parietal cells and decreased bile secretion. Loss of tone in the gastrointestinal tract may result in constipation. Some systems, however, show little change \vith age. For example, liver function tests do not change with age, and there is no decline in hematocrit \vith advancing age up until the ninth or tenth decade.
Various parts of the body age at different rates
Recent studies suggest that learning, memory, reaction time, and problem-solving ability decline very late in life. The rate of change in function varies not only from one person to another, but \vithin a person, from one individual organ to another. For this reason, knowing the condition ofa person's kidneys tells little about the state of his heart.
The changes associated \vith aging generally begin as soon as the gro\vth and development of a particular body subsystem are completed. In other words, there is no plateau of optimal functioning during the middle years. People do not stay "in their prime" for 20 or 30 years and then suddenly age. Instead, loss of function is uniform into the eighth and ninth decades. Elderly people are losing function at the same rate as younger people-an 80 year old person is aging at the same rate as a 30 year old; he has simply aged longer. 10
20 Nutrition for older persons
People tend to differ more as they grow older. Babies resemble each other more in behavior and physical growth than do adolescents. The elderly show still more individual variations, as Dr. Swansonll has pointed out:
A person at 70 is an historical record of all that has happened to him-his injuries, infections, nutritional imbalances, fatigues, and emotional upsets. Old people, therefore, differ from each other much more than do younger folk. All this needs to be considered in food planning for any older person. Each one is an individual, quite unlike anyone else.
Individuals age at different rates
Chronological age is a poor predictor of functional ability. Some 80 year olds function as well as the average 40 year old, and some 40 year olds perform like the average 80 year old.IO
Age-related changes occur in practically every part of the body 6.to.12-14
The bones decrease in density. Lean body mass tends to be lost, whereas adipose tissue and connective tissue generally increase. The heart may pump blood less efficiently. Blood flow may be reduced because of atherosclerotic deposits in the blood vessels and less elastic walls. The rate of renal blood flow is often reduced, and the kidneys are less efficient in removing waste products from the blood. Nerve signals are transmitted at slower speed. The lenses ofthe eyes lose the ability to focus a t near distances, and elderly people usually need brigh ter light to see without glasses than do young adults. Hearing loss is common, especially for high tones. Smell and taste may become less acute,15-li and loss of teeth may make che\ving difficult. Digestion may become slightly impaired as a resul t of decreased hydrochloric acid secretion by the parietal cells and decreased bile secretion. Loss of tone in the gastrointestinal tract may result in constipation. Some systems, however, show little change \vith age. For example, liver function tests do not change with age, and there is no decline in hematocrit \vith advancing age up until the ninth or tenth decade.
Various parts of the body age at different rates
Recent studies suggest that learning, memory, reaction time, and problem-solving ability decline very late in life. The rate of change in function varies not only from one person to another, but \vithin a person, from one individual organ to another. For this reason, knowing the condition ofa person's kidneys tells little about the state of his heart.
