Nutrition and Healthy Aging

Definition

Older Americans are living longer, healthier lives than their predecessors. Advances in medicine, medical technology and public health are largely responsible, but so are increases in public awareness of healthy eating and nutrition . Healthy aging is also associated with changes in eating patterns and dietary requirements due to age-related decreases in energy needed for daily activities and certain nutritional deficiencies common in older adults. Most age-related changes in food preferences and appetite are perfectly normal and are not considered nutritional disorders, but individual adjustments in dietary intake may be needed to ensure that health is maintained during senior years.

Description

Getting good nutrition is important throughout life, and especially for senior adults. Healthy eating helps them adapt to changes in lifestyle and nutritional requirements, and promotes healthy aging. Age-related changes in nutritional needs include a 25% reduction in calorie requirements because of reduced activity levels, a possible reduced amount of total body fluids, as well as changes in appetite and metabolism that can affect absorption of nutrients consumed in food. If an older individual does not receive proper nourishment to meet these changing needs, poor nutrition status (malnutrition ) can result, contributing to development of the degenerative diseases of aging.

Guidelines for a healthy diet have been developed for senior adults over age 55, including Dietary Guidelines for Americans and MyPyramid, which advise that the principle foods to eat are those rich in nutrients such as whole grains, beans, and fresh whole fruits and vegetables. These basic food groups provide adequate minerals, proteins, vitamins and energy to help ensure good nutrition and healthy aging. Protein sources include poultry, fish, eggs, soy, nuts, low-fat dairy and occasional lean meats. Whole grain sources of carbohydrates such as brown rice, whole grain pasta, millet, and barley, along with fresh vegetables provide a long lasting energy supply, increasing blood glucose slower than consuming refined foods (foods made with white flour and white sugar, high fructose corn syrup and packaged foods). For people with an unhealthy lifestyle (i.e., no exercise , poor diet), consuming too many refined foods can lead to insulin resistance, a pre-diabetic condition. Whole foods provide good sources of fiber in the diet to help maintain colon health. Complex carbohydrates obtained from whole fruits and vegetables simultaneously provide a better source of calories than is obtained from dietary fat.

Fats also provide energy. The healthiest sources of fats are polyunsaturated or monounsaturated fats found in soy, canola, and olive oils and nuts and avocados, as opposed to saturated fats found in meat and dairy products, which are known to raise cholesterol levels. Processed foods like margarine, baked goods, and certain frozen meals contain hydrogenated fats (trans fats) that have been shown to be harmful. As people age, hormone changes alter the way fats are metabolized in the body. It is important to choose fats that do not lead to accumulation of fatty deposits that damage veins and arteries (atherosclerosis ) and cause heart disease or stroke . Along with good nutrition and sufficient fiber, the body needs adequate hydration; it is important for older adults to drink eight glasses of water a day to help the kidneys and liver function properly to filter waste from the body and bloodstream.

Age-related nutritional deficiencies must be considered in addition to eating a healthy general diet. Senior adults are commonly deficient in calcium , vitamins D and B12, and folic acid (folate).

Calcium is critical for strong bones and teeth throughout life. It helps regulate heart rate, transmit nerve impulses, lower cholesterol and prevent muscle cramps. It is also an important component of normal blood clotting. Deficiency of calcium can result in osteoporosis , high blood pressure , and tooth decay. Calcium is found in milk and dairy products, sardines, seafood, green leafy vegetables, almonds, seaweeds, figs, soybeans, tofu, parsley, and alfalfa. It can also be taken as a supplement.

Vitamin D is required in order for calcium to be absorbed and utilized by the intestinal tract. It also helps prevent and treat osteoporosis, increases immune system functioning, and is required for thyroid function and normal immune function. Vitamin D can be obtained by getting sufficient sunlight or it can be taken as a supplement with calcium. It is found in relatively few foods such as oily fish and fortified margarines.

Vitamin B₁₂ (cyanocobalamin) is needed for development of healthy red blood cells and to prevent anemia . Digestion and absorption of nutrients from food requires the presence of vitamin B12, as does the synthesis of proteins by the body. Vitamin B12 also supports nerve function and prevents nerve damage. In seniors, B12 deficiency is often caused by poor absorption, resulting in pernicious anemia, fatigue, depression , and memory loss . Vitamin B12 is available as a supplement. Among food sources, it is found in most animal foods.

Folate is needed for generating energy and forming healthy red blood cells. It aids in protein metabolism and helps relieve depression and anxiety . Not having enough folate can result in anemia and general weakness. When taken as a supplement, folic acid is best taken with vitamin B12 and vitamin C . Folate can be found in brewer's yeast, green leafy vegetables, beef and lamb, lentils, split peas, wheat germ, and whole grains.

Demographics

Research has shown that 15–50% of all American adults over age 65 are not receiving adequate nutrition. Individuals at greatest risk of poor nutrition status include older adults living alone, and those with lower income, less education, and living in institutional settings such as nursing homes rather than in the community. Men living alone are at greater risk for low nutrition status than women, and rural individuals at greater risk than city dwellers. The Administration on Aging reports that three-fourths of African American seniors and two-thirds of white American seniors eat fewer than five servings of fruits and vegetables daily, an example of insufficient intake of nutrients. In developed western countries, up to 15% of community-living seniors and between 23% and 62% of hospitalized seniors were found to have protein-energy malnutrition. In a Swedish study, increased numbers of deaths were shown from heart disease, kidney disease and stroke in elderly individuals with malnutrition when compared to those of the same age group who had adequate nutrition and the same underlying diseases, showing a correlation between low nutritional status and incidence of disease.

Purpose

The purpose of re-evaluating nutritional needs of aging adults is to ensure healthy aging, which means maintaining appropriate food intake and weight, meeting daily energy requirements, and reducing degenerative processes that should not be considered inevitable. Certain normal age-related changes in eating habits, digestion and energy needs may lead to nutritional disorders. Specific nutritional disorders require evaluation of individual nutritional status and dietary intake to avoid adverse effects such as weight loss , malnutrition, and nutritional deficiencies that can lead to illness if not corrected. Making necessary dietary adjustments on an individual basis can mean the difference between healthy aging and increasing risk for age-related disease.

Challenges

The biggest challenge in advising seniors to follow a standard healthy diet is that somewhere between ages 50 and 60, important age-related changes influence the nutritional needs of each senior adult based on individual body weight, mass and general health status. While these changes may be part of normal aging, they must be addressed as part of any individual diet plan so that health is maintained in later years.

Age-related changes in appetite and food intake

As senior men and women move into their sixties, they tend to be less hungry, eat smaller meals, consume food more slowly, and snack less between meals. General age-related decline in physical activity means that less energy is spent than in earlier years. Because the intake of energy through food is typically greater than the decline in energy requirements, some individuals lose body weight and muscle, a condition called the anorexia of aging. Even though it commonly occurs, this condition is not good for all aging adults.

Age-related changes in body weight

Body weight and body mass increase gradually in all adults, only declining at around age 60. The number of overweight individuals decreases at this point because the death rate is higher in obese individuals, and the number of underweight individuals increases. Effects of body weight on health indicate that underweight individuals who continue losing weight are at increased risk for disease and death, while overweight individuals are advised to lose weight to avoid early death from obesity .

QUESTIONS TO ASK YOUR DOCTOR

• Is my weight and body mass satisfactory?
• How can I know if my nutrition is adequate?
• Is there a specific diet I can follow for good weight and good health?
• If my diet is not ideal, what is my risk for age-related diseases?

Age-related changes in body composition

Older adults have more body fat and less body mass (body mass index or BMI) than younger adults. The fat is found in different places such as more fat than muscle, and more in the abdomen than under skin tissue generally. This is directly related to decreased physical exercise and activity and changes in hormone activity and fat metabolism. These changes may result in increased insulin resistance, a characteristic of a pre-diabetic state.

Age-related malnutrition

Low body weight and low body mass are directly related to poor nutrition or malnutrition in older individuals. Protein-energy malnutrition is common in senior populations worldwide and is associated with reduced muscle function, lower bone mass, immune system disorders, reduced mental abilities, poor healing of wounds and poor recovery from surgery, and higher risk of disease and death.

Another challenge is that nutrition varies for each individual and one diet does not fit all. Each aging adult has a different genetic makeup and related body structure, and a unique history of dietary patterns, exercise habits, illnesses and injuries, stresses and trauma, emotional responses, and attitude toward life. Although certain age-related changes are known to occur in dietary needs and metabolism, individual histories have brought seniors to their current condition and level of functioning, which must be evaluated separately to determine individual needs for optimum health. Standard dietary guidelines for aging adults provides a nutritional foundation, but each individual may need evaluation for special dietary needs based on current health status, ideal weight, energy requirements to handle physical activity levels, and living conditions such as living at home alone or with family, living in a nursing center or other facility, and ability to shop and prepare foods. Evaluation of this kind can be done in a physician's office, a local medical center, or a community health services group.

Risks

Research has shown that risk for degenerative disease increases with decreases in nutritional status. Poor nutrition leads to higher risk of reduced muscle function, lower bone mass, immune system disorders, reduced mental abilities, poor healing of wounds, poor recovery from surgery, and higher risk of disease and death. Loss of muscle tissue (skeletal muscle) has been shown to be associated with three times greater incidence of physical disabilities in women over age 65 and nearly five times greater incidence in men over age 65. Unhealthy weight status of senior adults, including obesity and weight loss in already underweight individuals is linked to increased risk for disability and life-threatening disease states.

KEY TERMS

Folate —The salt form of folic acid.

Insulin resistance —Reduced ability of insulin to lower blood sugar levels.

Metabolism —The entire range of chemical and physical changes in body tissue that result from the consumption and utilization of biochemical nutrients, including conversion of molecules within tissue into useful metabolites or waste. For example, protein metabolism is the synthesis of proteins in body tissue.

Protein-energy malnutrition —Deficiencies in proteins or energy or both as a result of inefficient calorie consumption.

Results

Good nutrition and regular physical exercise have been shown to promote health and independence in senior adults, reduce the incidence and severity of degenerative disease, and increase longevity. Healthy eating increases independence of seniors by helping to maintain eyesight and hearing, cognition, physical endurance, and mobility while reducing the risk of heart disease, stroke, cancer , diabetes, osteoarthritis and osteoporosis.

Resources

BOOKS

Balch, P. A. “Vitamins, Minerals.” Prescription for Nutritional Healing. Garden City Park, NY: Avery, 1997.

Dietary Guidelines for Americans, 2005, 6th ed. U.S. Department of Health and Human Services, US Department of Agriculture. Washington, D.C.: U.S. Government Printing Office, January 2005.

PERIODICALS

Chapman, Ian. “The Anorexia of Aging.” Clinics in Geriatric Medicine 23, no. 4 (November 2007): 735–756.

Moritsugu, Kenneth P. “Healthy Aging Starts with Healthful Eating.” Journal of the American Dietetic Association 107, no. 5 (May 2007): 723.

OTHER

Erstad, Shannon. “Healthy Aging: Getting the Nutrition You Need.” Healthy Aging Health Center. June 22, 2006 [cited April 14, 2008]. WebMD. http://www.webmd.com/healthy-aging/tc/healthy-aging-getting-the-nutrition-you-need.

ORGANIZATIONS

American Dietetic Association, 120 South Riverside Plaza, Chicago, IL, 60606-6995, (800) 366-1655, http://www.eatright.org.

Center for Healthy Aging, National Council on Aging, 1901 L Street, Washington, DC, 20036, (202) 479-1200, (202) 479-0735, http://www.healthyagingprograms.org.

United States Department of Agriculture, Food and Nutrition Information Center, 10301 Baltimore Avenue, Beltsville, MD, 20705-2351, (301) 504-5719, http://www.nal.usda.gov/fnic.

L. Lee Culvert