Nutrition and the Elderly

By: Omar Shamieh, M.D.

Excerpt from original article

While adequate nutrition is important for all age groups, for older adults it is of particular importance in order to ensure physical, emotional, and psychological well being. Aging is associated with many changes that make elderly individuals vulnerable to illnesses.  Inadequate nutrition and weight loss in the elderly can manifest in many forms, and result from various factors.

There are several adverse outcomes of inadequate nutrition and weight loss in the elderly (such as deterioration in health, body composition, and physical function).  These result in cognitive decline, increased health recourse utilization, frequent hospitalizations, and early institutionalization.

A prevailing myth among many individuals, and even health practitioners, that nutritional inadequacy and weight loss is a consequence of aging and disease, and intervention is less valuable. Growing evidence shows that this is not the case, and early recognition of this problem and intervention has a positive impact on the health of the particular individual.

Growing baby boomers

In the United States in 2000, 35 million people (12.4%), or about 1 of every 8 Americans, were 65 years old or older. Women made up almost 60% of the elderly population (20.6 million) (2). By 2030, the 65+ population is expected to more than double to about 70 million people, representing 20% of the entire U.S. population (3). Currently in the developed world, the elderly make up 15% of the population.  In 2030, they will be around 25%. (5)

Impact of the problem

Only 1% of elderly who are independent and healthy are malnourished.

The Health and Nutrition Examination Survey (HANES) data indicated that 16% of community-dwelling Americans older than 65 years consumed fewer than 1000 calories per day. These statistics would place these people at high risk for under-nutrition (1).

The incidence of malnutrition ranges from 12% to 50% among the hospitalized elderly population and from 23% to 60% among institutionalized older persons (1).

In 2001, the U.S. elderly poverty rate increased to 3.4 million (10.1%) after it reached a historically low rate of 3.2 million in 1999 (4).  In 2001, 2.2% of the elderly population lived in severe poverty (below 50% of the poverty threshold, or below $4,247 for one senior) and 6.5% were classified as near-poor (incomes between 100% and 125% of poverty) (4).

Leading factors

Usually multifactorial, the leading factors can be divided into multiple domains: physiological, pathological, psychological, environmental, and socioeconomic.

Physiological changes with aging:

Normal aging involves steady decline in certain organ reserves.  Lean body mass decreases and body fat increases, as a result the energy requirement also decreases and protein reserves during a period of stress will be unavailable.  Decreased basal metabolic rate will decrease the food desire or hunger drive, which subsequently will lead to decreased food intake and weight loss.

Increase incidence of insulin resistance (hyperglycemia) in part due to increase body fat, will lead to reduced sensitivity to thirst, dehydration, and electrolyte imbalances. A decrease in the stomach acid secreting capacity can lead to defective absorption of certain food elements and vitamins.

Other changes include an altered sense of taste, decreased sense of smell, impaired hearing and vision, delayed gastric emptying, and decreased coordination.  All these factors will lead to a decrease in oral intake, ineffective absorption, and subsequently weight loss.

Pathological factors include poor oral health and dentition, dysphagia, gastric reflux, diarrhea, constipation, mal-absorption state, diseases states, and medication and substance abuse (such as alcohol, tobacco, drugs, and caffeine).

Acute conditions like respiratory, urinary infections and chronic illness (e.g., diabetes, renal disease, and cancer) all can lead to an increased metabolic demand and  decreased food intake.