As a group, individuals over 60 years of age are one of the fastest growing segments of the population. For example, in 1995 there were 14.1% male and 17.7% female Canadians 60 years or older. In the year 2020, it is projected that 24.7% of the male and 28.5% of the female population in Canada will be over 60 years of age. In the United States, 25 million Americans or 11% of the population are 65 years or older. This age group is expected to reach 57 million in the year 2030, an increase of 32 million. Australia also has a considerable aging population segment. By the year 2020, it is estimated that 21.4% of male and 24.7% of female Australians will be over 60 years of age.
Our understanding of the aging process remains poor. Nevertheless studies on aging have shown that it is associated with the progressive loss of physiologic capacity or function in all organs of the body. There is a progressive loss of cells in all tissues resulting in diminished functioning units. However, nutrition research suggests that optimal nutrition and physical fitness can slow the aging process and promote optimal health.
Nutrient Requirements
The current recommended daily nutrient intakes for older adults are similar to those for younger adults. The exception is energy; the need decreases with age. The nutrients that are commonly observed to be inadequate in diets of elderly individuals include: protein, calcium and iron.
Energy
Energy requirements decrease as one ages for three main reasons. With aging, the body tissues tend to change in composition to relatively more fat and less muscular tissue. The reduction in active tissue alone will lead to a reduction in energy expenditure and energy requirement. There is also a decrease in the basal metabolic rate which relates to the decrease in active cell mass. The basal metabolic rate decreases about 20% between the ages of 25 and 65. As well, decline in physical activity is common. The process of replacement of lean mass with fat can be delayed if the person remains physically active.
As people grow older, they tend to eat less and this compensates, to some extent, for the reduced energy needs. However, this can be accompanied by inadequate consumption of the essential nutrients if nutrient dense foods are not selected. This is especially true for women who have an even lower energy requirement than men.
Protein
The protein needs of older persons are not different from those of younger, healthy adults. The recommended level of protein intake is 0.8 g/kg body weight. The mean protein intake of individuals beyond 65 years of age, particularly women, tends to fall below the recommended level. Foods of high protein density, such as eggs or meat, should be included in the diet.
Calcium
Inadequate calcium intake is a concern as it may contribute to bone diseases such as osteoporosis and osteomalacia often seen in elderly people. Osteoporosis is characterized by a reduction of bone mass, bone fragility and pain. Approximately 25% of postmenopausal women are afflicted with this problem. Although evidence to demonstrate a direct relationship between decreased calcium intake and osteoporosis is not available, a habitually low calcium intake is generally considered a major contributory factor in this disease.
The recommended dietary calcium intake for elderly individuals is 50% higher than that of younger adults. However, the level of calcium in the diets of elderly people is commonly low. Furthermore, their reduced ability to absorb dietary calcium due to decreased gastric acidity compounds the problem.
Iron
The recommended iron intake for older men is similar to that for younger adult men. The recommendation for postmenopausal women is lower than for menstruating women and is similar to the recommended iron intake for men. Iron deficiency is a common problem among the elderly. It results from decreased absorption and/or inadequate iron intake. Iron deficiency in the elderly can cause fatigue, disorientation, confusion and loss of memory.
Folate
Folate supplementation in amounts 1-2 times the RDA is regarded as helpful in lowering elevated plasma homocystine levels and thus may lower the risk for vascular diseases and neural tube defects (NTD). As of January 1996, the FDA mandated fortification of wheat flour and grain products with folate. However, due to malabsorption of vitamin B12, prevalence of vitamin B12 deficiency in older adults is twice as common as in younger adults.
High folate intake may mask vitamin B12 deficiency and may thus delay its diagnosis and treatment. The Food and Nutrition Board has therefore advised that elderly people should also receive vitamin B12 through fortified food and/or vitamin B12 supplementation.
Use of Supplements
Many older adults are motivated to use dietary supplements to slow the aging process, improve health, increase energy level or prevent chronic diseases. Studies have shown that 35 to 70% of older Americans regularly use one or more nutritional supplements in the form of pills, capsules or drinks. Women tend to use nutritional supplements more than men. These supplements include antioxidants, vitamins, minerals and also homeopathic formulations. Evidence of benefits is scant, however.
Factors Influencing Food Intake
Many of the nutrition-related problems observed among the elderly are related to poor life-long eating habits. However, there are other factors (both social and health) that lead to nutritionally inadequate diets. Some of the social problems include:
- limited income and, therefore, purchasing power;
- loneliness, unhappiness and bereavement;
- social isolation;
- decreased mobility and activity;
- lack of support from family, friends and community; and
- food fads.
Some of the health-related factors include:
- chronic health problems;
- gastrointestinal disturbances and discomfort, hypochlorhydria;
- mental disturbances such as depression, confusion, dementia;
- physical incoordination and immobility;
- drug use;
- restricted diets;
- alcohol abuse;
- taste and smell aversion and sensory loss; and
- poor dental health and ill-fitting dentures.
Principles for Feeding the Elderly
In general, for “healthy” elderly individuals, diets should follow available food guides. Special consideration is given to:
- adequate energy intake;
- nutrient dense foods, especially for protein, iron and calcium;
- adequate fluid intake; and
- good sources of dietary fiber.
Attention should be given to the following in planning successful diets for the elderly:
- Individual preferences. Foods that do not conform to established habits may be physically and emotionally disturbing;
- Social, religious, racial and psychological factors, in addition to lifestyle;
- Preparation and presentation of meals. They must be attractive, appetizing and provide a consistency and texture acceptable to the consumer;
- Variety of foods. A wide choice of food would tend to provide balanced nutrition and a greater chance of acceptance. This would also avoid monotony in eating; and
- Flexibility in the number and time of meals. For some individuals small feedings of four or five times a day may be desirable.
Of considerable importance for the well-being of the elderly is regular physical activity. Keeping fit maintains cardiovascular fitness, muscle tone and normal bone density. Active individuals are less likely to suffer from osteoporosis.
