Undernutrition in the elderly

Undernutrition is one of the most common and devastating conditions in the older population. Thirty to forty percent of men and women over the age of 75 are at least ten percent underweight. Full-blown undernutrition occurs in 5% to 12% of community-dwelling older persons, in 11% of medical outpatients, and in 20% of higher risk community-dwelling populations. In hospitalized older adults, protein-calorie undernutrition reaches epidemic proportions, with a reported frequency between 32% to 50%. In institutionalized, long-term cave settings an even higher prevalence of undernutrition (23%–85%) has been reported. The devastating consequences of undernutrition include a higher mortality, greater functional decline, more frequent infections, and higher rates of adverse complications in all settings.

Nutritional status often worsens during hospitalization or institutionalization, despite efforts to provide adequate calories and protein. The impact of psychological and social contributions to the regulation of food intake have often been poorly appreciated. Frequently, efforts to increase voluntary consumption of food have not been successful, leading to attempts to involuntarily increase consumption through enteral or parenteral feeding. Despite a great deal of research, these nutritional strategies have not always produced clear-cut clinical benefits.

This issue of Clinics in Geriatric Medicine is devoted to an exploration of the state-of-the-art knowledge and of the frustrating dilemmas of nutritional therapy. An outstanding cadre of world experts in nutrition have graciously contributed to this volume.

John Morley begins with an explanation of the changes in appetite regulation accompanying aging. Wija A. van Staveren explores the regulation of appetite in older persons who are classified as frail by their medical conditions. John deCastro reports fascinating research about the psychological factors affecting food intake and potential interventions. The European perspective of undernutrition in older persons is reported by L.C. de Groot. The interaction of gustatory senses and dental conditions upon food intake is discussed by Christine Ritchie.

The diagnosis of undernutrition lacks a single gold standard. The complexity of identifying undernutrition is addressed in three articles. Louay Omran discusses the general approach to the diagnosis of undernutrition and Bruno Vellas reports on the development of a validated instrument for the diagnosis of undernutrition. Identifying undernutrition in office practice settings is addressed by Margaret Wilson.

The role of vitamin and mineral nutrition in older adults is complex. The intricacies of recommended therapy for micronutrients are discussed by Marie Bernard and Craig McClain. Forming a dietary prescription for chronic disease states remains controversial. Current standards (and controversies) for atherosclerosis, diabetes, and chronic obstructive pulmonary disease are reviewed. Unfortunately, a common response to confusion in the nutritional ranks has attracted older adults to fad diets and quick fixes, as discussed by Connie Bales.

Nutritional interventions have in general been disappointing. Efforts to stimulate appetite and thus increase food intake have shown some promising results. The pharmacological role of orexigenic agents in stimulating appetite is discussed by John Morley. Rami Haddad reviews the outcome and methodology of enteral feeding in older persons. A hypothetical reason to explain the disappointing results of hypercaloric feeding may result from a failure to distinguish starvation (which should be readily reversible) from cachexia (which is resistant to hypercaloric feeding).

I would like to thank the authors for their insightful discussions of a complex clinical issue. This issue should stimulate discussion of an epidemic and sometimes frustrating aspect of geriatric medical care.