Malnutrition in the elderly is an underrecognized condition that is increasing in prevalence as the population ages. The term malnutrition is often used to describe a deficiency in nutrition that causes adverse effects on the body and its normal functions.1,2 Although malnutrition can occur at any age, it is especially prevalent in people >60 years of age.1-4 Poor nutritional status is well established as a negative prognostic indicator in the elderly population, and weight loss in individuals >60 years of age approximately doubles the risk of dying.5
Despite the availability of several validated nutritional screening tests, many cases of malnutrition go undiagnosed, leading to increased morbidity and mortality, prolonged hospital stays, and frequent hospital readmissions.5,6 It is therefore important that healthcare providers be able to identify the causes and signs and symptoms of malnutrition. If identified early, malnutrition can be treated with proper adherence to a nutritional intervention plan.2 Early recognition and treatment of malnutrition are not only beneficial for the patient’s health but can reduce overall cost to the healthcare system.7
As people get older they tend to become more sedentary and their body composition changes, resulting in an increase in body fat and a decrease in lean muscle mass and extracellular fluid. The body responds to the need for less energy by decreasing appetite, a process known as “anorexia of aging.”2
The etiology of weight loss and malnutrition in the elderly has been attributed to psychologic, physiologic, and environmental factors.1,2 These components are frequently referred to as the “9 Ds” of weight loss in the elderly (Figure).1,2
Dementia is a cognitive impairment that results in deterioration in memory or executive function and mostly affects the elderly population.8 Individuals with dementia can have impairment in activities of daily living, including the ability to shop, prepare food, manage money, and remember to eat.8,9 Sleep disturbances can affect cognitive and physical function.10-12 Impairments such as decreased arousal, disorientation, and reduced ability to maintain upright posture may make feeding oneself difficult.
Patients with dementia are often dependent on another individual to help them meet their nutritional needs. However, many patients do not have the financial resources needed to hire caregivers or have family members who are willing and/or able to undertake these tasks.4,8,9
The loss of taste is an impairment in the ability to detect sweet, sour, salty, and bitter tastes.13 Impaired taste buds decrease the ability of the elderly to differentiate between basic tastes and may lead to a decrease in the pleasure of eating and quality of life.1,13 The cumulative effect of this often results in decreased appetite, leading to poor food intake and weight loss, which contribute to malnutrition. Some common causes of dysgeusia are poor dentition, poor oral hygiene, oral dryness, oral bacterial growth, smoking, and changes in the tongue.13
Chronic diarrhea is defined as diarrhea that is present for longer than 4 weeks.14 Weight loss is commonly seen with many causes of chronic diarrhea and can lead to malnutrition.1,2,14 The most common causes of chronic diarrhea are medication use, osmotic disorders, secretory conditions, inflammatory conditions, malabsorptive conditions, motility disorders, chronic infections, and systemic diseases.14
Depression in the elderly is often underrecognized. There are many variables that affect the incidence of depression, such as sex, marital status, cognitive status, ability to perform activities of daily living, and social interaction.15 Research has found an association between depression and decreased nutritional status.15 Although more studies are needed to confirm this relationship, depression has been shown to be an independent predictor of poor nutritional health and a major cause of weight loss leading to malnutrition.2,15
Dysphagia — the inability to eat, drink, or swallow — is often present in the elderly and can be caused by a mechanical obstruction or a neurologic condition affecting the esophagus.16 Normal swallowing involves oral, pharyngeal, and esophageal phases, all of which are performed without conscious effort hundreds of times a day. Dysphagia occurs when normal swallowing is disrupted.16 A study published in 2002 revealed that 50% of participants admitted to eating less because of dysphagia, and 44% had weight loss.17 Dysphagia makes eating an unpleasant experience that contributes to poor eating habits, resulting in malnutrition.16
Any disease can have a negative effect on nutritional status and contribute to malnutrition. Individuals with cardiac disease and chronic obstructive pulmonary disease, as well as those who have experienced a stroke, have been found to have an increased nutritional need but often fail to meet the nutrient and protein goals set for them.18The American Diabetes Association has specific dietary recommendations that are often difficult for geriatric patients to follow. This results in nutritional imbalance, leading to microvascular disease, which is often manifested in the heart, eyes, and kidneys.2,18 Diabetes has been associated with a faster loss of muscle strength and an increased rate of disability in the elderly population.
Poor dental health and the loss of teeth can affect the ability to chew and limit choice of foods, which can have an adverse effect on maintaining proper nutrition.2,19 A study conducted in Spain revealed that persons with dental defects experienced a higher rate of malnutrition.19 Although these problems can be corrected with dental care and the use of proper-fitting dentures, geriatric patients living on a fixed income often cannot afford proper dental care and/or dentures.19
As people age, their level of polypharmacy generally increases.20 The 6 most frequently prescribed classes of medications in the elderly are gastrointestinal agents, antihypertensives, diuretics, analgesics, beta-blockers, and antihyperlipidemic agents.20 Medications may be prescribed by different providers who unknowingly set patients up for unwanted adverse effects and drug interactions that may cause decreased food consumption and nutrient intake and absorption, resulting in poor nutritional status.2,20
Dysfunction of the immune system can lead to increased infection and delayed wound healing, which can directly contribute to malnutrition.1 Altered gut integrity leads to increased intestinal infections that can affect the absorption of nutrients.1 Physical dysfunction that impairs engagement in activities of daily living can hinder a patient’s ability to obtain and prepare food, worsening nutritional status.1,6
Other aspects of malnutrition that are not directly covered in the “9 Ds” are sex, resources to purchase food, accessibility to food, living conditions, and existence/strength of family and social networks.2,19