Nutrition in Older Adults
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GERIATRIC GASTROENTEROLOGY, SERIES #12 Series Editors: T.S. Dharmarajan, M.D., and C.S. Pitchumoni, M.D. Nutrition in Older Adults by Ajit J. Kokkat, T.S. Dharmarajan and C.S. Pitchumoni Older adults and health care providers are confronted with an array of developments in the area of geriatric nutrition. The nutraceutical industry is expanding and new cat- egories like functional foods, prebiotics and probiotics have emerged. The role of diets in prevention of cancer, cardiovascular disease and cognitive disorders is being recog- nized. Severe calorie restriction to enhance longevity may be difficult in humans since associated protein, vitamin and trace element deficiencies may occur. Homocysteine has assumed significance in the area of vascular disease and dementia. The health care provider must be aware of nutritional advances and spend sufficient time on dietary counseling during the patient encounter. INTRODUCTION lenge is with early diagnosis. Malnutrition encompasses s health care costs in the US rise with aging and a variety of conditions including over and under nutri- obesity trends, the focus will be on dietary habits tion of protein, energy and nutrients (1). If defined as A contributing to morbidity and mortality. Life “decreased nutrient reserves,” malnutrition exists in up expectancy has increased worldwide with an increase to 15% of ambulatory outpatients, 35% to 65% of hos- in the number of older adults. Another noticeable trend pitalized elderly and 25% to 60% of long term care res- is an epidemic of obesity. The well publicized food idents (1). Global malnutrition, defined as reduced pyramid recommended for the general US population intake or increased requirements for proteins and calo- has been modified for older adults whose nutritional ries is common in the geriatric age group and associated requirements are quite different. The nutrition industry with comorbidities such as anemia, pressure ulcers, has evolved after landmark legislation over the years infection, sarcopenia, cognitve impairment and overall (Table 1). Adequate nutritional counseling will help functional decline, with an increase in mortality (2). older adults lead healthy lives. Optimal nutritional status is an important compo- ANOREXIA AND AGING nent of health and even more so in the elderly. Although malnutrition is easily diagnosed in late stages, the chal- The consumption of food is modulated by sociologic (e.g. quantity of meals eaten in a group is larger than Ajit J. Kokkat M.D., Fellow, Gastroenterology, Our when alone), psychologic (e.g. favorite desserts), Lady of Mercy Medical Center, University Hospital of physiologic (e.g. more food is consumed in the New York Medical College, Bronx, New York. T.S. evening in preparation for the overnight fast) and Dharmarajan, M.D., FACP, AGSF, Associate Profes- genetic factors (3). Taste, vision, hearing and olfaction sor of Medicine, New York Medical College, Chief, play large roles in food enjoyment. Olfaction is con- Division of Geriatrics and Director, Geriatric Medicine sidered the most important factor in food enjoyment; Fellowship Program Our Lady of Mercy Medical Cen- the threshold of detecting smells consistently increases ter, University Hospital of New York Medical College, with aging and the capacity for odor identification Bronx, New York. C.S. Pitchumoni, M.D., MPH, decreases (4). Taste is often altered by many medica- FACP, MACG, Chief, Division of Gastroenterology, tions, with bitter and sweet taste affected more com- Hepatology and Nutrition, St. Peters University Hospi- tal, New Brunswick, New Jersey. (continued on page 24) 22 PRACTICAL GASTROENTEROLOGY • JUNE 2004 Nutrition in Older Adults GERIATRIC GASTROENTEROLOGY, SERIES #12 (continued from page 22) Table 1 role of leptin, which increases with aging in women Landmark nutritional legislation (31) but declines in men, is not clear (3). Anorexia of aging (physiologic and/or pathologic) 1990 Nutrition Labeling and Education Act increases the risk of protein-energy malnutrition. • FDA mandate uniform labeling of foods Common disorders associated with a decline in • Establish claims about content and disease prevention appetite include diabetes, hypothyroidism, zinc defi- 1994 Dietary Supplement Health and Education Act ciency, renal failure, depression and cancer (6). In sev- • Defined dietary supplements, established procedures eral of these disorders, cytokines such as tumor necro- to ensure safety, regulating health claims, label sis factor, interleukin-1 and interleukin-6 are elevated supplements and encourage research and cause anorexia, loss of muscle mass and cachexia 1997 FDA Modernization Act (6). Other factors that influence food intake include • Allowed health claims not authorized by FDA if ethnicity, financial status, living alone, reduced mobil- supported by the National Academy of Sciences or ity, accessibility to food sources, cognitive status and National Institutes of Health other less recognized factors (4). Meals eaten with one or more persons tend to be larger, but in reality older monly (5). Both ageusia (loss of taste) and dysgeusia people are more likely to eat alone (7). The ambience (altered taste) may result from use of medications. Fla- of the setting also makes a difference, with better vor enhancement (e.g. using monosodium glutamate) intakes noticeable in restaurants than at home (8). may increase food palatability and acceptability (5). Meal composition also influences intake. Older adults Older adults eat smaller meals and tend to experi- tend to eat less carbohydrates and fats and consume ence satiety easily; this is attributed to a combination fewer calories than younger persons (3). of decreased fundal accommodation and more rapid antral distension (6). Although not definitely proven, the secretion of a number of gut hormones is altered as DRUGS AND APPETITE age advances. There is some evidence that the levels of Several medications have adverse effects on appetite cholecystokinin, a satiety hormone, increase with and consequently on nutritional status; examples aging; it slows gastric emptying and sensitizes the include anticholinergics, antihistamines, antibiotics, antrum to distension (4). Amylin, an anorexia agent, digoxin, theophylline, NSAIDs, iron supplements and also increases with aging (3). Ghrelin, a stomach hor- psychotropic drugs (Table 2) (5). Reduction of func- mone, stimulates food intake and reduces fat metabo- tional capacity and failure to thrive has been reported lism; ghrelin levels may decline with aging (5). The to result from the use of metoclopramide for gastro- paresis and nausea in older Table 2 adults (9). The presence of glu- Drugs and effect on nutrition (6,9,45) cose in the duodenum increases hunger in older persons unlike Effect Examples young adults (5). Therefore, liq- Drugs reducing appetite anticholinergics, antihisamines, antibiotics, digoxin, uid glucose supplements given Drugs increasing appetite benzodiazepines, glucocorticoids, amitriptyline an hour prior to a meal could Drugs altering taste captopril, metronidazole, lithium Drugs causing dry mouth diuretics, clonidine, tricyclic antidepressants not only provide calories but Drug absorption reduced by food levodopa, phenytoin, theophylline also stimulate appetite. Thera- Drug absorption increased by food carbamazepine, metoprolol, diazepam peutic diets with various restric- Foods reducing drug metabolism grapefruit juice tions may be unnecessary, espe- Foods increasing drug metabolism broccoli, cauliflower, citrus cially in the nursing home set- Drugs causing folate deficiency phenytoin, antacids, aspirin Drugs causing calcium deficiency tetracyclines, phenytoin ting. Appetite-stimulating or Failure to thrive metoclopramide orexigenic drugs are available. (continued on page 29) 24 PRACTICAL GASTROENTEROLOGY • JUNE 2004 Nutrition in Older Adults GERIATRIC GASTROENTEROLOGY, SERIES #12 (continued from page 24) Table 3 Cyproheptadine is not very effective and may cause Nutritional recommendations for the elderly (11,46,47) delirium (10). Anabolic agents e.g. testosterone, oxan- drolone and nandrolone increase muscle mass but tend Variable Comment to cause liver dysfunction (10). Megesterol acetate Calories Average daily caloric needs 30Kcal/day increases appetite in older adults especially patients Carbohydrates 55 to 60% of total calories with cancer or AIDS, but therapy should be discontin- Protein 0.8g/Kg body weight/day ued after 12 weeks due to adrenal suppression (10). Fats Reduce dietary cholesterol and saturated fats Dronabinol, obtained from cannabis, may be useful in Less than 30% of total calories demented or hospice patients (10). Terminal anorexia Water 30 mL/Kg body weight/day (loss of appetite at end-of-life) should be differentiated Minimum 1500 mL/day unless contraindicated from reversible anorexia and managed with attention e.g. CHF to symptom relief rather than caloric intake. Fiber 25–30 g/day with adequate water Vitamin A 600–700 µg retinol equivalents/day Toxicity more common due to increased gut NUTRITIONAL ASSESSMENT absorption and decreased liver metabolism Deficiency uncommon in older adults Accurate nutritional assessment may be difficult in older adults due to presence of cognitive impairment, anerg y Vitamin B6 1.3 mg/day Deficiency causes hyperhomocysteinemia to intradermal antigens, physical disability and lack of Vitamin B12 2.4 µg/day age-based normograms (11). Modified food guide pyra- Food-cobalamin malabsorption most common mids reflect the different nutritional