Part I of a two-part series
The rapid "graying of America" has prompted increased interest in exploring the needs of older Americans. Research on the nutritional needs of older people is no longer on the "back burner" but has moved to the forefront of scientific interest and attention. The primary reason for the increased attention to the health needs of these Americans is that they make up a large proportion of the population—and it’s growing rapidly. Why the growth? One reason is that during the 20th century life expectancy roughly doubled from approximately 40 years to almost 80 years. This longer life span, combined with the wave of aging Americans contributed to an 11-fold growth in the over-65 segment of the population during the 1900s. (Census bureau statistical brief from USDA Nutrition Insights) In fact, the over-65 age group is the most rapidly growing segment of the American population, and within this group the number of those over age 85 years is increasing most rapidly. (Journal of The American Dietetic Association 10/96) Experts predict that more than 12 million Americans will be over age 85 by 2040.
Changing Nutritional Needs
Nutritional needs change with age. As people become older, a balanced and varied eating pattern remains important, but certain health conditions and lifestyle factors—as well as general physical needs—can alter nutritional requirements. Data from the third National Health and Nutrition Examination Study (NHANES III) suggest that older people are at particular risk of inadequate diets because of the presence of chronic disease, physical disability, poor teeth, multiple medications, limited income, and social isolation. In addition, a decreased sensitivity of taste and smell and a sedentary lifestyle can adversely affect nutritional status.
In general, older people need at least the same amounts of vitamins and minerals as they did when they were younger. Some major changes also affect nearly every person as he or she ages. These include:
- A decrease in caloric needs by 25 percent
- Increased susceptibility to dehydration due to a reduced sense of thirst and bodily changes
- Increased use of medications that can affect both appetite and vitamin and mineral needs
Leslie Bonci, a spokesperson for The American Dietetic Association, emphasized that, because of these factors, older people need to get more "bang for their buck" in nutritional terms. "Some people can optimally fulfill nutrient needs by eating more frequent minimeals with a glass of water each time," explained Bonci. "Also, quantity of food, not quality changes with age. Select foods with high nutrient density such as whole grains, legumes, low-fat dairy foods, fruits, and vegetables with color to the flesh like dark green and deep orange, red or yellow," she added.
Specific Nutrient Needs for Aging Americans
With lower levels of food consumption and decreased caloric needs, getting the proper amounts of nutrients becomes a greater challenge—and often at a time in life when interest in nutrition and cooking is waning. Although there is scientific discussion and even some controversy surrounding the appropriate nutrient recommendations for older people, strides have been made in determining more accurate estimations of nutrient needs for this age group. The following nutrients were chosen for close examination because the Recommended Dietary Allowances (RDAs) or Dietary Reference Intakes (DRIs) of these nutrients for older people differ substantially from those for younger adults.
Protein: Most people think of protein as necessary for a growing body, but even though adults and older people have stopped growing, protein-containing foods are still important for good health. Protein is essential for maintenance of body tissue and helps keep the immune system functioning properly. Insufficient intake of protein can result in an accelerated loss of muscle mass (which is already a problem for older people), an increased risk of infection, and low energy reserves during infection or illness.
According to The American Dietetic Association, women and men over the age of 50 should consume 60 to 75 grams of protein per day, depending on individual weight-this is a higher level than that for younger people. Some experts theorize that older people may have a decreased ability to utilize protein efficiently in the body and therefore require more of it to make up the difference. Also, older people who are home-bound or living in elder-care facilities are more likely to have protein-calorie malnutrition, so extra care should be given to overall food intake, protein intake, and general diet quality for these individuals.
Protein Tips:
- Stretch your budget by keeping meat, poultry, and fish portions small, while adding other less expensive protein sources such as eggs, peanut butter, legumes, and dairy products to the diet.
- Chop meat or poultry into small pieces if they are hard to chew. Have teeth and gums checked if chewing difficulties prevent you from achieving a good diet.
Calcium and Vitamin D: Calcium is the most abundant mineral in the body and one that’s important for both men and women. The body uses calcium to keep teeth and bones strong, but calcium is also vital for the contraction and relaxation of muscles (including the heart muscle), blood clotting, and making new cells and body tissues. In addition to its major role in the prevention of osteoporosis, calcium may also have important roles in decreasing the risk of kidney stones (when the calcium is from food sources), limiting the growth of cancer cells in the colon, and controlling blood pressure.
Most older people do not get enough calcium, and diets that are low in calcium are frequently low in vitamin D as well. In addition to inadequate intake, certain medications can interfere with calcium and vitamin D absorption and retention.
Vitamin D’s importance in helping calcium function optimally can not be overstated. While dairy products are often fortified with vitamin D, older people who do not tolerate dairy products well can be at significant risk for low vitamin D status. As people age their ability to absorb vitamin D (and therefore calcium) is diminished because of fewer intestinal vitamin D receptors. Most people know that our bodies can make vitamin D if our skin is exposed to sunlight; however, even that ability fades with age.
For all of these reasons, the DRIs for calcium and vitamin D are higher for older people than for others.
Calcium Tips
If dairy products are not well tolerated, try the following:
- Drink smaller amounts
- Drink reduced-lactose milk
- Take lactase enzyme tablets
- Choose yogurt with live, active cultures
Vitamin B6: The DRI for vitamin B6 (also called pyridoxine) for older people is substantially higher than that for adults of other ages. This is due to the well-documented age-related declines in levels of vitamin B6 in blood and the substantial body of evidence that shows that vitamin B6 levels of older populations is low. This is another case in which medications can have an adverse effect on the vitamin levels as well.
Low vitamin B6 (as well as low folate) levels are associated with increased homocysteine levels. Homocysteine is now recognized as an important marker of coronary artery disease and stroke. Even aside from this, however, low vitamin B6 levels are associated with insulin resistance, and there is some evidence of increased prevalence of carpal tunnel syndrome when levels of the vitamin are low. Adequate Vitamin B6 intake can aid the functioning of the immune system, can assist in the metabolism of food, and is necessary for red blood cell formation, among other things.
Vitamin B6 Tip
Sources of vitamin B6 include bananas, whole-wheat bread, chicken, eggs, oatmeal, peanut butter, pork, potatoes, brown rice, tuna, shellfish, and walnuts.
Looking to the Future
Additional research on the nutritional needs of older people is in full swing and shows no signs of letting up anytime soon. According to Bonci, a focus on disease prevention and the prevention of disease progression will continue, and additional research into antioxidants and phytochemicals will be of interest to people in this age group. As we look to the future, the availability of more fortified foods such as calcium-fortified milk and juices and cereal fortified with folic acid will provide older adults with new and varied ways to eat well and stay well.
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Dietary Reference Intakes for Older Individuals
|
|
Ages 51 to 70
|
Ages 70+
|
|
Nutrient or Mineral
|
Females
|
Males
|
Females
|
Males
|
| Calcium |
1,200 |
1,200 |
1,200 |
1,200 |
| Phosphorus |
700 |
700 |
700 |
700 |
| Magnesium |
320 |
420 |
320 |
420 |
| Vitamin D |
10 |
10 |
15 |
15 |
| Fluoride |
3 |
4 |
3 |
4 |
| Thiamin |
1.1 |
1.2 |
1.1 |
1.2 |
| Riboflavin |
1.1 |
1.3 |
1.1 |
1.3 |
| Niacin |
14 |
16 |
14 |
16 |
| Vitamin B6 |
1.5 |
1.7 |
1.5 |
1.7 |
| Folate |
400 |
400 |
400 |
400 |
| Vitamin B12 |
2.4 |
2.4 |
2.4 |
2.4 |
| Pantothenic Acid |
5 |
5 |
5 |
5 |
| Biotin |
30 |
30 |
30 |
30 |
| Choline |
425 |
550 |
425 |
550 |
Source: National Academy of Sciences, 1999.
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Recommended Dietary Allowances for Individuals Ages 51 and Older, Revised 1989 (Abridged)
|
|
Nutrient or Mineral
|
Females
|
Males
|
| Protein (g) |
50 |
63 |
| Vitamin A (RE) |
800 |
1000 |
| VitaminE ((TE) |
8 |
10 |
| Vitamin K (µg) |
65 |
80 |
| Vitamin C (mg) |
60 |
60 |
| Iron (mg) |
10 |
10 |
| Zinc (mg) |
12 |
15 |
| Iodine (µg) |
150 |
150 |
| Selenium (µg) |
55 |
7 |
