Nutrition and Aging

Eat a variety of foods to stay healthy.
As we age, it becomes more important that we eat more calcium, fiber, iron, protein and vitamins A, C and folacin.
To reduce calories select nutrient-dense foods. Enjoy smaller portions of foods high in fat, sugar and sodium.
The Aging Body
Physiological changes occur slowly over time in all body systems. These changes are influenced by life events, illnesses, genetic traits and socioeconomic factors.

Sensory Changes
Sensory changes include a decline in sight and peripheral vision, hearing, smell and taste. The losses are neither total nor rapid, but they do affect nutritional intake and health status.

Loss of visual acuteness may lead to less activity or a fear of cooking, especially using a stove. Inability to read food prices, nutrition labels or recipes may affect grocery shopping, food preparation and eating. This could have an adverse effect on nutritional status.
Loss of hearing may lead to less eating out or not asking questions of the waiter or store clerk.
Changes in smell and taste are more obvious. If food doesn't taste appetizing or smell appealing, we don't want to eat it. If we must cut back on salt, sugar or fat, we may tend not to eat.
Structural Changes
As we age, we lose lean body mass. Reduced muscle mass includes skeletal muscle, smooth muscle and muscle that affects vital organ function, with loss of cardiac muscle perhaps the most important. Cardiac capacity can be reduced and cardiac function impaired by chronic diseases such as athero-sclerosis, hypertension or diabetes. Changes also occur in the kidneys, lungs and liver, and in our ability to generate new protein tissue. In addition, aging can slow the immune system's response in making antibodies.

The most significant result of the loss of lean body mass may be the decrease in basal energy metabolism. Metabolic rate declines proportionately with the decline in total protein tissue. To avoid gaining weight, we must reduce calorie intake or increase activity. The goal is energy balance.

Loss of lean body mass also means reduced body water -- 72 percent of total body water is in lean muscle tissue.

Total body fat typically increases with age. This often can be explained by too many calories. As we age, fat tends to concentrate in the trunk and as fat deposits around the vital organs. However, in more advanced years, weight often declines.

Finally, we lose bone density. After menopause, women tend to lose bone mass at an accelerated rate. Recent attention has focused on the high incidence of osteoporosis. Severe osteoporosis is debilitating and serious.

Fractures and their associated illness and mortality are certainly a concern. Also, vertebral compression fractures can change chest configuration. This, in turn, can affect breathing, intestinal distension and internal organ displacement.

Nutrition can be a factor in all of the changes noted above. However, the slowing of the normal action of the digestive tract plus general changes have the most direct effect on nutrition. Digestive secretions diminish markedly, although enzymes remain adequate. Adequate dietary fiber, as opposed to increased use of laxatives, will maintain regular bowel function and not interfere with the digestion and absorption of nutrients, as occurs with laxative use or abuse.

Suggestions for Coping with Change
Sensory changes
Loss of smell and taste affect the nutritional intake and status of many seniors. If food does not smell or taste appetizing, it will not be eaten.

Suggestions:

Try a variety of new food flavors. Experiment with low sodium seasonings such as lemon juice, dill, curry and herbs of all types (see fact sheet 9.354, Sodium in the Diet).
Sometimes the problem is not dulled senses, but rather a drab, soft diet. Don't cook vegetables until they are mushy. Instead, reawaken the senses to fresh, flavorful foods and new textures
Loss of teeth
Improperly fitting dentures may unconsciously change eating patterns because of difficulty with chewing. A soft, low-fiber diet without important fresh fruits and vegetables may result.

Suggestions:

Have poorly fitting dentures adjusted.
Chop, steam, stew, grind or grate hard or tough foods to make them easier to chew without sacrificing their nutritional value. Try a grated carrot and raisin salad.
Osteoporosis
Weight-bearing exercise and a diet high in calcium help protect against osteoporosis. Current treatments include estrogen replacement, exercise and calcium supplements. (See 9.359, Osteoporosis.)

Suggestions:

Walk, lift weights, swim or enroll in a group fitness or water aerobics class. Exercise at least three times a week and have fun!
Include two to four daily servings of dairy products such as milk, yogurt or cheese.
If digesting milk is a problem, cultured dairy products, like buttermilk and yogurt, often are tolerated well. Use lactaid, available in most stores, to make reduced lactose milk.
Post-menopausal women may need a calcium supplement if they can't get enough through diet alone. Talk to a physician or registered dietitian.
Specific Nutrient Needs
Calorie needs change due to more body fat and less lean muscle. Less activity can further decrease calorie needs. The challenge for the elderly is to meet the same nutrient needs as when they were younger, yet consume fewer calories.

The answer to this problem is to choose foods high in nutrients in relation to their calories. Such foods are considered "nutrient-dense." For example, low-fat milk is more nutrient dense than regular milk. Its nutrient content is the same, but it has fewer calories because it has less fat.

Protein needs usually do not change for the elderly, although research studies are not definitive. Protein requirements can vary because of chronic disease. Balancing needs and restrictions is a challenge, particularly in health care facilities. Protein absorption may decrease as we age, and our bodies may make less protein. However, this does not mean protein intake should be routinely increased, because of the general decline in kidney function. Excess protein could unnecessarily stress kidneys.

Reducing the overall fat content in the diet is reasonable. It is the easiest way to cut calories. This is appropriate to reduce weight. Lower fat intake is often necessary because of chronic disease.

About 60 percent of calories should come from carbohydrates, with emphasis on complex carbohydrates. Glucose tolerance may decrease with advancing years. Complex carbohydrates put less stress on the circulating blood glucose than do refined carbohydrates.

Such a regime also enhances dietary fiber intake. Adequate fiber, together with adequate fluid, helps maintain normal bowel function. Fiber also is thought to decrease risk of intestinal inflammation. Vegetables, fruits, grain products, cereals, seeds, legumes and nuts are all sources of dietary fiber (See fact sheet 9.333, Dietary Fiber

Source:
http://www.ext.colostate.edu/pubs/foodnut/09322.html