Nutrition for the Elderly

Introduction

elderly is legally defined as > 65; 13% of current population; 20% of population in 2030

elderly are not simply older adults just as infants are not simply little adults

aging is not synonymous with disease

aging is a heterogeneous process - everyone is affected differently

Physiologic Changes in Aging

chronological age and physiological age do not coincide Þ there is no age-defined ‘normal’

different organ systems age at different rates - even in the same individual

homeostasis is easily displaced and there is less capacity to return to homeostasis after injury

little room for error in treatment and in administration of drugs

compression of morbidity: less time between onset of disease and death

Body Composition: has the most important impact on health and nutrition

decrease in lean body mass (LBM) is approx. 2-3% per decade age 30 - 70

even elite athletes cannot prevent loss of LBM

decrease in bone mass for women is 1.3% per year 35 - 60; less than 0.002% after 70

associated with decreased vit D, decreased Ca absorption, decreased exercise

decrease in total body water

from decreased LBM and increased adipose
mostly affects intracellular water (major concern with regard to V_D of drugs)
also contributing: decreased urine concentration, decreased response to thirst

decreased body weight: if maintained, is due to increased adipose

impact of body composition changes

decreased LPM Þ decreased strength (first manifests in hand strength) Þ limited independent activity (ADL - activities of daily living)

raises chicken or egg issue: dis-use or aging?

decreased metabolic rate secondary to decreased LBM Þ ß caloric intake Þ undernutrition risk

preserving LBM

best way preserve LBM is to maintain energy expenditure and functional independence

generalized activity and aerobic activity – NO

does not translate to increased expenditure (i.e. run a few miles, then sleep more)

progressive resistance muscle strength training – YES

can increase muscle size and strength Þ increased expenditure and increased caloric intake

GI changes don’t lead to an inability to digest or absorb nurtients
decreased salivary secretions, esophageal motility, dysphagia
decreased gastric secretions, motility, surface area
decreased villi
constipation, increased diverticula, poor anal sphincter tone
liver function appears to be unaffected by aging

Sensory Loss

cephalic phase of eating is decreased Þ loss of motivation to eat

decreased sense of smell and taste lead to a high reliance on visual cues as motivation to eat

Anorexia Tardive: anorexia of later life

NOT a normal function of aging

common contributing factors are depression, pathologic grief, dementia, dysphagia, etc

Screening for Nutritional Risk

Nutritional Screening Initiative (NSI) identifies risk factors for malnutrition

inappropriate food intake, poverty, social isolation (eating in groups increases intake), decreased functional status, disease state, weight changes
a good, quick screening test

more comprehensive screening

assess nutrient supply and intake: includes dietary history, functional capacity, socio-economic environment
anthropometric measurements: height, weight, BMI, skin-fold, hip/waist

serial measurements over a period of time are important

biochemical data: must take into consideration normal values for elderly and effects of drug therapy

Nutritional Recommendations

maintenance of weight is the best marker of adequate nutrition

fluids: very important due to dilute urine and decreased thirst response

caloric requirements: difficult to determine, currently under investigation

protein: slightly higher than adults: 0.9 - 1.0 g/kg/day

vitamins/minerals: still under investigation

quality of life issues: will dietary restrictions cause more stress, anxiety, etc than necessary? - important consideration