Caballero B. (ed.) Encyclopaedia of Food Science, Food Technology and Nutrition. Ten-Volume Set

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The Concept of Frailty

0006 Frailty has been defined as the loss of a person’s

capacity to withstand minor environmental stresses.

Although ‘frailty’ is sometimes used to avoid a precise

definition of disability, in a more scientific way, it

may be useful to help health workers understand

what appears to be ‘a syndrome of multi-system re-

duction in physiological capacity compromising an

old person’s function . . . and leading to unstable

disability.’ In frail elderly people, just treating the

acute illness is often insufficient: in the clinical

context, reduced musculoskeletal function, aerobic

capacity, cognitive and neurological function, and

nutritional reserve are the features measured to define

frailty, because these deficits reduce the capacity for

interaction with the environment. In an old patient

presenting with an acute illness, all these different

aspects of reserve and function need to be optimized

if the patient is to have a chance of recovery. The

frailty syndrome is sometimes seen as a downward

spiral (or the ‘dwindles’ in the USA), and research

confirms the frequently very major role of nutrition

in the clinical context.

0007 It is clinically useful to diagnose frailty by measur-

ing the four key capacities, thereby identifying elderly

people at risk of unstable disability with a view to

reversing these problems if realistic. The suggested

methods for measuring the components of frailty for

muscle function include grip strength, ability to stand

from sitting, aerobic capacity by measuring a 6-min

walk in outpatients or a treadmill test, various cogni-

tive tests, and practical functioning tests to assess the

mind; and for nutritional state, body mass index (in

people unable to stand or markedly kyphosed, demi-

span or other measures can be used to estimate skel-

etal size). (See Nutritional Assessment: Functional

Tests.)

Nutrition, Diabetes, and Vascular Risk in

Migrant Populations

0008 It has been documented repeatedly that populations

of apparently all genetic descents other than from

temperate climates appeared to change from virtually

zero rates of vascular disease associated with obesity,

diabetes, hypertension, and hyperlipidemia (and a

combination of these – syndrome X) to very high

rates and severity of these if they moved from a

rural, underdeveloped life to a ‘western’-type urban

lifestyle. All these conditions are age-associated ill-

nesses and occur at younger ages, even sometimes

at reproductive ages in women, and more severely

than in European-descent populations. The changes

can occur within one generation and are generally

believed to be due at least in part to dietary changes

in combination with reduced energy expenditure

sometimes. This susceptibility to the Western lifestyle

is found in genetically extremely diverse populations

from Melanesia, the Indian Subcontinent, and Africa,

and indigenous Indian people in the Americas, etc.

Hunter–gatherers, who were the evolutionary ances-

tors of Europeans in a temperate climate, may have

evolved in response to increased meat-eating and

reduced vegetable intake in such a way that does

not affect fertility. Increased fat intake has been sug-

gested in the etiology of diabetes, e.g., in the Pima

Indians. Several intervention studies support this hy-

pothesis, e.g., if Australian Aboriginal people eat

their traditional diet for 5 weeks, it very quickly

reverses the diabetes and obesity that they present

with. Baschetti has emphasized the role of high-

density energy foods in causing these pathologies in

susceptible populations and stated that the concen-

tration of sucrose should not exceed 4.18 MJ l

1

Dietary potassium (in vegetables and fruit) is reduced

by Westernization, and, since it is protective in this

context, it has been suggested that potassium be

added to drinks. Tropical and subtropical diets have

a much larger ratio of vegetables to animal intake

compared with those from temperature climates and

it is interesting that the traditional Caribbean diet

is closest to the present UK government recom-

mended diet.

0009The high rate of vascular diseases in populations

of tropical or subtropical descent is not purely due

to these factors. Social factors are very significant,

too, poverty being responsible for about 38% of the

excess stroke morbidity in Afro-Americans compared

with Euro-Americans. The potential health gains

from lifestyle modification, however, clearly merit

investment in appropriate education and facilities.

Usual Weight Changes During Aging

0010Both undernutrition and obesity jeopardize the health

of old populations all over the world, particularly in

urbanized societies. Most data derive from developed

countries. Figure 1 shows the usual changes observed

cross-sectionally in a representative UK sample.

0011The average trend of a slight slow weight loss after

the age of 60 has been found in numerous surveys (see

Table 1): one exception to this was a study in New

Mexico on volunteers with no health problems and

whom the authors described as socially privileged and

unusually health-conscious. (Exclusion of any health

problems in a UK community survey in Nottingham,

which excluded old people living in institutions,

would have meant that 95% of the elderly volun-

teers would have been excluded.)

ELDERLY/Nutritional Status 2017

0012 Explanations for the slight but distinct tendency for

weight loss in old age are awaited. Metabolic changes

so far studied during aging would be compatible with

a tendency to gain weight. It has been suggested that

appetite is reduced during aging by neuroendocrine

changes. This ‘anorexia of aging’ should not be con-

fused with the distinct epidemiology of old patients

who notice anorexia and mention it to the health

team, and in whom a search for a specific cause has

a high yield. Low income, poor dentition, and solitary

eating may be important, as may be rising taste or

smell thresholds for which there is ample evidence.

Since about 95% of the elderly population living in

the community in the UK have some illness or limita-

tion, these conditions, the drugs prescribed for them,

or the social consequences of them also play a role.

Resting metabolic rate is lower in older subjects, even

after correcting for the changes in body composition,

so this alone would cause weight gain if the diet were

to remain constant or adjusting to energy expend-

iture. One hypothesis that might explain the observed

changes and for which there is some limited support

in research might be that, as we age, the energy costs

of daily activities increase. Several authors have dem-

onstrated that weight stability is associated with the

best health in old age. The converse has also been

shown: that weight loss is the most ominous predictor

rather than thinness itself. People who are observed to

be thin in old age include three groups: those who are

lean and fit throughout life, smokers who are lean

and not so fit, and those most at risk who have lost

weight recently. This last group may be perceived as

frail.

Body Composition Changes

0013During aging, there is a tendency for centripetal re-

distribution of fat, which is variable and includes

internal fat deposition. The consequent practical

problems for practitioners is the reduced use of limb

subcutaneous fat measurements to reflect total body

fat. Likewise, in old women especially, this trend plus

height loss associated with osteoporosis may produce

apparent abdominal protrusion and a very common

false label of obesity by doctors assessing on the basis

of abdominal examination. Muscle mass decreases

during aging, although physical training can to some

extent modify this trend. In illness or trauma, dehy-

dration is very common in old people as kidney water

conservation ability falls with age, and the threshold

to thirst commonly rises with old age.

Gut Changes During Aging

0014For most purposes, these are negligible in terms of the

old person’s nutritional status. Probably, the most

significant change is oral health, in particular the

dental health, which, time and again every year,

tbl0001 Table 1 Longitudinal studies reporting weight change in old age arranged in descending order of magnitude of weight change found

(combined group of men and women)

Reference Age (years) of subjects Duration of study (years) Number of subjects Weight change (kgper year)

Men Women

Steen (1988) 70–81 11 23 0.64 0.55

Stevens et al. (1991) >65 at entry 25 370 0.56*

Rissanen et al. (1988) 60–69 4–7 294 0.06 0.4

>70 4–7 0.36 0.7

Lehmann et al. (1996) 65–100 4 629 0.21 0.34

Williamson et al. (1990) 65–74 10 1856 0.11 0.17

Garry et al. (1992) 60–84 9 157 ns 0.14

Friedlander et al. (1977) 65–69 5 1813 ns

>70 5 ns

ns, not significant.

16−24

25−34 35−44 45−54

Age (years)

Body mass index (kg/m

)

55−64

Women

Men

65−74

75+

fig0001 Figure 1 Mean body mass index by age and sex: health survey

for England.

2018 ELDERLY/Nutritional Status

is shown in many studies to be a relevant factor in

explaining undernutrition in the elderly. Esophageal

motility may become disordered occasionally during

aging, but a much more common finding is in the

stomach, where gastric acid production may be re-

duced. The importance of this in terms of health is

particularly the increased risk of gastroenteritis be-

cause the acid barrier is reduced. The small bowel and

large bowel have a considerable reserve function,

and aging per se is unlikely to affect this unless of

course diseases develop.

What is Optimal BMI in Old Age?

0015 With this question comes that of ‘who defines the

norm’? Tables most widely available for adults are

based on young white volunteers. There are only a

few longitudinal data available at present upon which

to base BMI advice for elders in any population, and

tables are mostly norms using percentiles based on

cross-sectional studies, point surveys, and ‘healthy’

elderly volunteers rather than on health outcomes,

unfortunately. As with all BMI descriptive data, the

BMI norms have increased, particularly in Western-

ized societies, first in the USA and now in Europe.

The norms established in the 80s were apparently no

longer valid in the 1990s. The definition of ‘norms’ is

particularly problematic in old age: in a typical UK

community free-living volunteer elder population,

only 5% of the over-65s have no medical problem.

If all illnesses were excluded in establishing norms,

these tables would be based on 5% of the elderly

population – who could thus be described as super-

fit elders. Compared with our knowledge about

younger people, this state of ignorance regarding old

people and BMI needs explaining, and may reflect the

lack of research investment by public bodies and

private companies.

Population Studies

0016 A 1996 review on BMI in old age relied on data from

a 1979 survey (Build Study) and had no people aged

over 69 (see Table 2). What can be seen from this

table, however, is that the optimum BMI in terms of

mortality apparently rises very significantly with age.

In Finland, a whole population local survey in Tam-

pere of people aged 85 years and older showed a

correlation between longer survival and higher BMI

(see Figure 2).

0017 A very large US survey of 22 000 subjects also

showed a flattening of the U-shaped curve relating

BMI to mortality with increasing age cohorts. The

obesity risks of vascular disease and cancer do not

disappear in old age, but it has been argued that

selective survival of those less vulnerable to these

risks occurs. The Nottingham Longitudinal Study of

Activity and Aging, which measured BMI and health

in 629 relatively well but not super-fit elders living in

the community at the time of the initial survey, inter-

estingly showed neither an increase in morbidity nor

an increase in mortality in the low BMI volunteers

initially and at 4-year follow-up. One possible ex-

planation for this apparent anomaly is that whereas

most population surveys include significantly dis-

abled or ill elderly subjects, if these people are

excluded, thinness has no apparent ominous signifi-

cance, at least not over 4 years. This fits with the

emphasis many authors and clinicians have put on

nutrition reserve in elders and the importance of

regaining this reserve after intercurrent illness or

trauma. Nevertheless, the subject cannot be said to

be fully understood as yet, and confounders are very

likely to be significant and to vary from sample to

sample. What the data do suggest, however, is that if

old people are fit, well, and mobile, thinness has little

ominous significance, but in any studies that include

hospital attenders, it appears that thinness is a very

powerful predictor of poor outcome.

0018In terms of disability prevention, the data from the

US National Health and Nutrition Examination

tbl0002Table 2 Effect of age on body mass index associated with the

lowest mortality

Age group (years) Bodymassindex (kgm

2

)

Men Women

20–29 21.4 19.5

30–39 21.6 23.4

40–49 22.9 23.2

50–59 25.8 25.2

60–69 26.6 27.3

Data from Build Study 1979.

0.4

0.6

0.8

1.0

Relative survival rate

1.2

1.4

1.6

<20.0 103

102

28.0 81

Body mass index No

26.0−27.9

8124.0−25.9

22.0−23.9

20.0−21.9

Years of follow up

2345

fig0002Figure 2 Five-year relative survival curves according to body

mass index in subjects aged 85 and over.

ELDERLY/Nutritional Status 2019

Survey (NHANES) in 1994 supported the U-shaped

curve hypothesis: both extremes of BMI in elderly

volunteers apparently independently predicted worse

functional status (independence in activities of daily

living) (Figure 3). In the old group of women who had

lost more than 5% of their weight over 8–16 years,

there was an associated doubling in the rate of mobil-

ity disability, even after adjustments were made for

age, smoking, and education. Weight loss rather than

thinness was again the main predictor of poor

outcome. In a detailed description of the NHANES

follow-up, it was found that the initial BMI at both

15% extremes was an independent predictor of

disability in old men and old women, even 11–13

years later, even after correcting for 22 potential

confounders, and even after excluding those who

died within 2 years of the first survey (in whom, it

might have been argued, weight loss was a result of

illness).

0019BMI ranges are therefore a changing phenomenon

over time both within and between elderly popula-

tions. At present, outcome data are lacking on which

to base advice to an elderly person regarding opti-

mum weight, except that overweight is clearly related

to joint pains. Survival is reduced in thinner elders

overall, but a high waist–hip ratio is probably not

advisable in the presence of hypertension, vascular

disease, or diabetes.

Hospital Patients

0020Surveys of nutritional status and health in old age

that include disabled, ill, or traumatized elderly pa-

tients consistently highlight thinness and recent

weight loss as powerful ominous independent pre-

dictors of health outcome. Although, with different

methods, hospital inpatient surveys yield a wide

range of prevalences for undernutrition in old hos-

pital inpatients, in the UK, 40% is accepted by Gov-

ernment Department documents. The commonness

of thinness in old inpatients may explain why staff

(unlike relatives) usually miss the diagnosis and has

prompted the growth of screening tools of varying

efficacy. Research suggests that, so far, no question-

naire screening tools to be administered by nurses on

general wards are safe, unlike their use by dieticians,

and safer alternatives are either anthropometry or

simply an eyeball estimation of whether the patient

is thin, average, or fat: the nurse is asked to tick the

relevant box. (See Nutritional Assessment: Functional

Tests.)

0021The association and ominous significance of

malnutrition with illness and disability are likely to

be complex. In some cases, the illness or disability, or

their attendant pharmacological and social conse-

quences, may precede and cause negative energy

balance. In others, the causal relationship may be

reversed. In the clinical context, therefore, it is crucial

to tackle both the illness and the malnutrition, if

appropriate, and, to avoid recurrence, an attempt

should be made to determine the sequence of events

in each individual: sometimes, a third factor will have

caused both the illness and the malnutrition simultan-

eously. In a study on very acute illnesses leading to old

people’s admission, using retrospective dietary histor-

ies, it was found that, compared with control groups,

these patients had had lower dietary intakes over the

preceding month – even though the criterion for in-

clusion was that the patients were absolutely fine the

day before the day of admission. This suggests that

Male

Female

< 5

5−15 15−85

BMI rank

Relative risk

85−95

> 95

fig0003 Figure 3 Relationship between body mass index percentile

rank and relative risk for functional impairment for men and

women. Final logistic regression model after removing from the

sample those 307 persons who died within 2 years of the comple-

tion of the NHANES-I Epidemiologic Follow-up Study (n ¼2746).

tbl0003 Table 3 Factors associated with high-risk undernutrition in old

age

Environmental causes

Poverty

Social isolation

Depression

Social construction of disability (being housebound)

Individual factors

Poor dentition

Chronic lung disease

History of gastric surgery

Cognitive impairment

Dysphagia

Bereavement and depression

Alcohol excess

Recent unintended weight loss of 3 kg

2020 ELDERLY/Nutritional Status

undernutrition may cause or precede very acute ill-

ness. Of course, in the clinical context, the reverse is

also often found.

0022 Frequently, depression and physical illnesses pre-

sent simultaneously in the elderly, and in many, a

vicious circle is present by the time treatment starts:

malnutrition can perpetuate anorexia by increasing

small bowel microbial overgrowth, which is even

more likely to follow undernutrition in the elderly

than in children because of the high prevalence of

age-associated achlorhydria (in atrophic gastritis,

now known to be due to Helicobacter pylori infec-

tion) in elderly patients. When depression and anor-

exia are both very marked and coexist in old age,

endoscopy is indicated. In stroke patients, weakness

in swallowing is commonly compounded by starva-

tion from the time of stroke, and tube feeding is

required to correct this starvation weakness of the

bulbar muscles.

0023 Negative energy and nitrogen balance very quickly

and severely impair immune function, even in fit

elderly volunteers, and even within 9 weeks of

starting on an equal-calorie but low-protein diet. In

the clinical context, it has been demonstrated that a

low lymphocyte count, which can have numerous

causes (e.g., inflammation, undernutrition), correl-

ates closely with the risk of readmission of the

patient.

0024 What is less well known in elderly care is the im-

portance of careful management of the refeeding syn-

drome, and work is awaited to see whether this and

consequent hypophosphatemia are being missed, as is

our clinical impression, in a number of cases of eld-

erly patients in hospital. (See Elderly: Nutritionally

Related Problems; Nutritional Management of Geri-

atric Patients; Phosphorus: Properties and Determin-

ation; Physiology.)

0025 In rehabilitation wards for the elderly, research has

confirmed very elegantly that poor nutritional status

on admission and, in particular, weight loss during

the preceding year are the most powerful independent

predictors of poor outcome, even after correcting for

numerous potential confounders, including 22 that

did correlate with outcome. Equally important ran-

domized controlled trials of nutritional supplemen-

tation have demonstrated lasting positive outcomes in

elderly hip fracture patients and pneumonia patients:

functional ability in the long term benefitted from

the intervention, and average hospital stay was

shortened.

0026 When viewed together, these data explain the

primary concern regarding undernutrition in elderly

patients and consequent rejection of blanket obesity-

avoidance advice intended for other adults, which is

sometimes inappropriately followed by old patients.

0027-Specific nutritional deficiencies in hospital patients

Certain micronutrient deficiencies in old inpatients

denote specific pathological conditions. Iron defi-

ciency in old age (in particular postmenopause) in

developed countries is due to gut pathology (e.g.,

ulcer or cancer) in over 90% of cases, according to

two London studies. Vitamin D deficiency may be

due to anticonvulsant medication, folate deficiency

may reflect anticonvulsant medication but, more

commonly, inadequate diet due to poor self-care,

and this is common in early dementia. It was so

common that it was thought to cause dementia,

although, at present, the consensus appears to be

that early dementia leads to difficulty organizing

food if people are living on their own, and the

first lab routine test to show this is folate. Folate

deficiency is also very commonly associated with

alcoholism. (See Elderly: Nutritionally Related

Problems.)

0028Immobility itself in old age has been shown to be

associated with more rapid protein turnover than is

seen in fit peers: it was demonstrated long ago that, in

the UK, housebound elderly people are in negative

nitrogen balance. If protein turnover is more rapid in

the elderly during immobility (and endocrine mecha-

nisms are possible), a slight imbalance of intake or

expenditure will lead more rapidly to more muscle

loss while the body prioritizes visceral protein syn-

thesis. This may explain the downward spiral of

frailty sometimes seen in ill, traumatized or disabled

patients.

Nutritional Status in Elderly Nursing Home

Residents

0029Undernutrition is very common in this group. Many

residents barely eat enough to maintain basal metab-

olism. The reason for poor nutritional status in ad-

vanced dementia may vary, and research has produced

a range of answers, including insufficient time spent

helping at meal times, inappropriate food consistency,

and possibly a change in energy balance control. Drug

effects on appetite or bowels and nutrient utilization

also need to be considered in each case. Energy ex-

penditure generally drives energy intake in humans – if

an old person is less mobile, their appetite will there-

fore be reduced and micronutrient deficiencies will,

and often do, result if the nutrient density of the food

is not appropriately increased. Vitamin D deficiency is

common in housebound elders without access to

sunlight, and sufficient vitamin D consumption

would require an unacceptably high intake of fatty

fish. Quite why there are such high rates of general

undernutrition in this group, however, is unclear,

even if the individual micronutrient deficiencies are

easier to explain. (See Elderly: Nutritionally Related

ELDERLY/Nutritional Status 2021

Problems; Nutritional Management of Geriatric

Patients.)

0030 In 1995, the Caroline Walker Trust produced mul-

tidisciplinary guidelines for optimal nutrition for in-

stitutionalized elderly. It is written to be understood

by service users and service providers, and covers

food provision, dental checks, weight monitoring,

etc. plus triggers for referral for medical review (any

unexplained 3-kg weight loss). The importance of

formulating an individualized plan suitable for each

elderly resident is emphasized.

0031 Ethical questions regarding the degree of interven-

tion considered appropriate in terminal illness and in

dementia frequently occur in this setting. In several

observational studies in nursing homes investigating

the management of advanced dementia patients who

appear not to be eating enough, tube feeding pro-

duced no benefit in terms of comfort and none in

terms of survival.

See also: Elderly: Nutritionally Related Problems;

Nutritional Management of Geriatric Patients; Nutritional

Assessment: Functional Tests; Phosphorus: Properties

and Determination; Physiology

Further Reading

Campbell AJ and Buchner DM (1997) Unstable disability

and the fluctuations of frailty. Age and Ageing 26:

315–318.

Caroline Walker Trust (1995) Eating Well for Older People.

Report of an Expert Working Group. Practical and Nu-

tritional Guidelines for Food in Residential and Nursing

Homes and for Communal Meals. London: Caroline

Walker Trust.

Ebrahim S and Kalache A (eds) (1996) Epidemiology in Old

Age. London: BMJ Publishing Group.

Galanos AN et al. (1994) Nutrition and function: is there

a relationship between body mass index and the

functional capabilities of community dwelling elderly.

Journal of the American Geriatrics Society 42:

147–168.

Gillick MR (2000) Rethinking the role of tube feeding in

patients with advanced dementia. New England Journal

of Medicine 342: 206–210.

Lehmann A (1996) Nutrition and health – what is new?

Reviews in Clinical Gerontology 6: 147–168.

Rabeneck L, McCullough LB et al. (1997) Ethically justi-

fied, clinically comprehensive guidelines for percutan-

eous endoscopic gastrostomy tube placement. Lancet

349: 496–498.

Roth SG et al. (1999) Calorie restriction in primates: will it

work and how will we know? Journal of the American

Geriatrics Society 7: 896–903.

Tallis R (ed.) (1998) Increasing Longevity: Medical, Social

and Political Implications. London: The Royal College

of Physicians.

Nutritionally Related Problems

J B Blumberg, Tufts University, Boston, MA, USA

Introduction

0001Nutrition influences the progressive loss of tissue

function with aging and plays an important role in

the genesis of several major chronic degenerative dis-

eases. Aging influences nutritional requirements and

nutritional status through changes in appetite and in

pathways of nutrient absorption, utilization, and ex-

cretion (Table 1). Further, a variety of socioeconomic

and psychological factors as well as the presence and

treatment of current disease(s) common to older

adults affect dietary patterns and nutritional status.

Thus, some of the nutritional problems of the elderly

are the consequence of long-term (chronic) inter-

actions between diet and aging, beginning in adoles-

cence and young adulthood, while others are

associated with the more immediate (acute) result of

old age itself.

Acute nutritionally related problems

Anemia

0002The most consistently reported hematopoietic change

with aging is a higher prevalence of anemia which

increases with each successive decade of life. Al-

though anemia is prevalent among healthy elderly,

its cause does not generally appear to be due to hem-

olysis or deficiencies of iron, folate, or vitamin B

Elderly people with this unexplained anemia have

lower leukocyte and neutrophil counts than do non-

anemic subjects. Experimental and clinical studies

tbl0001Table 1

Change inphysiologic function Change in nutrient requirement

#Muscle mass (sarcopenia) #Calories

#Bone density (osteopenia) "Vitamins D and K, calcium

#Immune function (anergy) "Vitamins B

, C, and E, zinc

#Skin cholecalciferol synthesis "Vitamin D

"Winter parathyroid hormone

production

"Vitamin D

#Calcium bioavailability "Vitamin D

#Hepatic uptake of retinol #Vitamin A

"Oxidative stress status "b-carotene, vitamins C and E

"Levels of homocysteine "Folate, vitamins B

and B

#Efficiency in pyridoxal

utilization

"Vitamin B

"Gastric pH (gastric atrophy) "Vitamin B

and folic acid,

calcium, iron, zinc

2022 ELDERLY/Nutritionally Related Problems

suggest this anemia of aging is due to a reduction

in bone marrow reserve capacity (erythropoietin-

dependent progenitor cell proliferation) with de-

creased hormonal responsiveness to hematologic

stress. Chronic inflammation is also a possible

mechanism. However, any elderly individual with

anemia must be fully evaluated for the possibility of

drug-induced or occult gastrointestinal blood loss,

bone marrow failure, chronic hemolysis, and nutri-

tional deficiency before attributing an anemia to age

alone.

Anorexia and Weight Loss

0003 A decline in calorie intake is a well-recognized con-

comitant of increasing age. Surveys reveal that almost

20% of older adults consume less than 1000 calories

(4.2 MJ) per day; among institutionalized elderly and

those whose income is at poverty levels, the preva-

lence may increase twofold. Protein-calorie malnutri-

tion is a common finding among geriatric patients.

Marasmus may occur in older patients because the

combination of a small but balanced caloric intake

with a contribution from muscle-protein catabolism

is sufficient to maintain serum albumin. Thus, weight

loss is an ominous sign in the elderly which needs to

be taken seriously.

0004 The etiology of anorexia and weight loss in the

elderly is multifactorial and includes both physio-

logical and pathological causes. Age-related declines

in metabolic rate due to loss of lean body mass

(sarcopenia) and decreased expenditure of energy on

physical activity contribute to lower calorie intakes

in the elderly. Social factors such as poverty, isolation,

and requirements for assistance with food shopping

and preparation can be a source of impairment to

adequate nutrition. Physical factors such as disabil-

ities or immobility and poor oral health can also

interfere with conducting activities of daily living

associated with nutrition.

0005 Psychiatric disorders, e.g., dementias and depres-

sion, as well as states associated with bereavement

and isolation affect nutritional status. These condi-

tions are not uncommon among the elderly and are

usually associated with anorexia and weight loss.

Among institutionalized elderly with low body

weight and at risk of malnutrition or B vitamin defi-

ciency, a higher prevalence of dementia and depres-

sion is noted. Indifference, memory loss, impaired

cognition, and disturbed or erratic behavior associ-

ated with these conditions all contribute to reduced

food intake. Inadequate nutrition may further exacer-

bate psychiatric symptoms. Experimental studies

suggest an increased activity of the hypothalamic–

pituitary–adrenal axis production of corticotropin-

releasing factor and/or neuropeptide Y may be

involved in the anorexia of some of these psychiatric

conditions.

0006Several diseases common among the elderly affect

food intake. Chronic obstructive pulmonary disease

increases the effort required to eat. Congestive heart

failure is associated with anorexia which is aggravated

by the cachexic effect of cardiac glycosides used to

treat the condition. Some cancers and all antineoplas-

tic drugs can precipitate anorexia. Esophageal reflux

can lead to pain on swallowing and decreased food

intake.

0007Anorexia may also occur as a concomitant of

normal aging. Gustatory papillae begin to atrophy

in middle age and taste and olfactory thresholds

increase with age. Studies in old animals indicate a

reduced drive in the endogenous opioid feeding

system, particularly the k-receptor ligand dynorphin,

and the increased satiety action of the gastrointestinal

hormone cholecystokinin may provide a biochemical

basis for the anorexia of aging.

Constipation

0008Constipation is a common complaint among the

elderly, with women reporting this difficulty more

frequently than men. The discomfort associated

with constipation may affect an older person’s food

intake. The tone of intestinal smooth muscles and

gastrointestinal tract activity diminish with age.

However, the lack of dietary fiber, dehydration, and/

or immobility appear to be the primary causes of

most cases of uncomplicated constipation. A variety

of drug treatments common among elderly patients,

particularly those with anticholinergic actions, may

also cause severe constipation. The requirement for

assistance in using the toilet may cause an older adult

not to respond to the urge to defecate which can result

in a later inability to defecate at will due to desensi-

tization of rectal stretch receptors. Important compli-

cations of constipation in the elderly include fecal

impaction, abnormally large colon, and intestinal ob-

struction. Also, straining at stool may create sudden

severe circulatory changes in the aged. In most in-

stances, the treatment of simple constipation in the

elderly includes advice to increase fiber consumption

(and fluid intake) in the diet and/or as supplements

(e.g., vegetable mucilloids and modified cellulose

products). The pathogenesis of another age-related

condition of the colon associated with the absence

of fiber in western diets is diverticular disease.

Dehydration

0009Thirst and water intake are critical to the main-

tenance of fluid and electrolyte balance since it is

only through such intakes that water deficits can be

ELDERLY/Nutritionally Related Problems 2023

replenished. Fluid and electrolyte disorders are

common in the elderly and abnormalities in salt and

water homeostasis are a significant cause of morbid-

ity and mortality in geriatric patients. Older adults

respond to dehydration with greater increases in

plasma sodium concentration and osmolality than

young subjects, yet do not become markedly thirsty

and drink enough to dilute their body fluids to pre-

deprivation levels. Thirst in response to heat stress

and thermal dehydration is also reduced in the elderly

despite a reduced capacity for thermoregulation (heat

loss).

0010 The mechanism of the thirst deficit in the elderly is

not fully defined. Age-related changes in receptors

that detect dehydration of the cell (osmoreceptors)

and decreases in plasma volume (baroreceptors) and

in the endogenous opioid system have been suggested

to play a role in this condition. Changes in renal

function with age, such as diminished glomerular

filtration rate, urinary concentrating ability, and

sodium-conserving capacity, can act to reduce the

ability to conserve salt and water and predispose an

older person to hypovolemia and dehydration. The

decreasing activity of the renin–angiotensin–aldoster-

one system with age may also contribute to dimin-

ished sodium and water homeostasis in the elderly.

0011 Older adults may become dehydrated when ex-

posed to even mild stresses such as water restriction,

fever, infection, or diarrhea. When the diminished

thirst response in an elderly individual is accompan-

ied by illness or physical incapacity that increases

water loss or prevents access to water, dangerous

dehydration may follow. In the elderly, dehydration

is a common cause of renal impairment and failure

and electrolyte disturbances. Dehydration and hypo-

natremia can also lead to confusional states that fur-

ther interfere with fluid intake. While the extent of

dehydration in free-living elderly has not been estab-

lished, age-related impairments of thirst sensation

place them at risk of dehydration.

Gastric Atrophy

0012 Selective functions of the digestive tract experience

some diminution of function with age, although

many of these changes do not appear significantly to

influence nutrient requirements in the elderly. An

increased incidence of gastric acid hyposecretion

(hypochlorhydria) resulting from atrophy of the gas-

tric glands of the fundic mucosa of the stomach is

noted among about 30% of people over 60 years.

This gastric atrophy (type A) is asymptomatic but,

when the condition is severe, is associated with perni-

cious anemia due to a decreased secretion of intrinsic

factor. Gastric atrophy is also associated with faster

gastric emptying rates and a higher pH with bacterial

overgrowth in the proximal small intestine. These

latter effects of gastric atrophy may interfere with

the bioavailability of several nutrients, including cal-

cium, iron, folic acid, and vitamin B

. In addition to

absorbing or utilizing these nutrients, the overgrowth

of some aerobic organisms may contribute to the

nutritional status of the host via the synthesis and

secretion of some nutrients, e.g., vitamin K. The

high intraluminal pH of the stomach and proximal

small intestine found in gastric atrophy may also

prevent the release of some nutrients from dietary

fiber or protein and other food complexes. Dietary

recommendations for several micronutrients should

be adjusted for older adults with gastric atrophy and

include the use of appropriate nutrient supplements.

Chronic Nutritionally Related Problems

Cancer

0013Cancer develops as a result of interactions between

genetic and environmental factors. An estimated 90%

of all cancer cases are attributed to environmental

factors, including tobacco smoking, radiation,

industrial pollutants, viruses, and diet. Analyses of

epidemiological studies suggest that 35% of cancer

deaths may be related to diet. Evidence linking diet

and cancer has been derived from experimental

in vitro and animal studies, metabolic and biochem-

ical studies in humans, and epidemiological investi-

gations. In general, the epidemiological studies have

demonstrated that populations migrating from an

area with its own pattern of cancer incidence rates

acquire rates characteristic of their new location. Fur-

ther, large changes in incidence rates for many types

of cancer within genetically stable populations have

been associated with changes in dietary patterns. Al-

though the cumulative data for the relationship be-

tween both the causal and protective effects of diet

and cancer are compelling, the evidence, particularly

with regard to quantitative levels of specific nutrients,

remains far from conclusive.

0014Various studies indicate that a high intake of total

fat increases the risk of some types of cancer, notably

cancer of the breast and colon but also of the prostate,

rectum, and ovaries. Cancer mortality correlates

better with total dietary fat intake than with the

type of fat. However, several epidemiological studies

have demonstrated a strong relationship between sat-

urated fatty acids or animal fat and increased cancer

risk. In contrast, animal studies indicate monounsatu-

rated and n-6 polyunsaturated fats promote carcino-

genesis more effectively, while n-3 fatty acids can

reduce tumor growth rates. Several mechanisms

have been proposed to explain the effects of fat on

2024 ELDERLY/Nutritionally Related Problems

cancer, including its alteration of steroid hormones

and endocrine changes, immune function, cell mem-

brane fluidity, and (for colon cancer) fecal floral and

bile acids. Excess body weight and obesity are also

associated with an increased risk of several cancers,

including those of the breast, endometrium, ovaries,

colon, rectum, prostate, and gallbladder. Other diet-

ary factors, including alcohol and naturally occurring

contaminants, e.g., aflatoxins and N-nitroso com-

pounds, also pose a potential cancer risk.

0015 Dietary patterns emphasizing foods high in fiber

are associated with low rates of certain cancers, espe-

cially breast and colon cancer. The protective effect of

fiber may be due to a concomitant reduction of total

calories and fat and/or by altering gastrointestinal

factors such as intraluminal pH, gut flora, and transit

time. Fiber-containing foods such as fruits and vege-

tables are also important sources of b-carotene, vita-

mins A, C, and E, phenols, and indoles as well as a

large number of other phytochemicals with potential

cancer-preventive activity. Generous dietary intakes

of b-carotene are associated with a reduced incidence

of lung, breast, oral mucosa, bladder, and esophageal

cancers; however, clinical trials with large supplemen-

tal doses of b-carotene resulted in an increased risk of

cancer among smokers. Vitamin C has a potentially

protective effect against esophageal, stomach, cer-

vical, breast, and lung cancers. Low intakes of vita-

min E are strongly correlated with risk of cancer in

many, but not all, organs. b-carotene and vitamins C

and E may share a related antioxidant, free radical

scavenging mechanism against carcinogenesis. Evi-

dence also suggests that calcium and selenium have

protective effects against some forms of cancer.

0016 While the evidence associating specific nutrients

with cancer risk remains equivocal, dietary guidelines

have been promulgated by a number of health organ-

izations which recommend avoiding obesity, reducing

total fat to 30% or less of calories, consuming high-

fiber foods and a variety of fruits and green and

yellow vegetables in the daily diet, and minimizing

the intake of alcohol and smoked, salt-cured, and

nitrate-cured foods. Evidence suggesting the ability

of these dietary patterns or supplementation with

putative protective nutrients to reverse existing

cancers or lower rates of cancer recurrence is limited

and equivocal.

0017 Established cancers as well as antitumor treatments

may have a variety of effects on the nutritional status

of the affected geriatric patient. Anorexia and weight

loss are common and may result in progressive

wasting and undernutrition (cancer cachexia). Alter-

ations in protein, carbohydrate, and fat metabolism

are associated with many cancers. Malabsorption and

protein-losing enteropathy are also a concomitant

of various malignancies. Hormonal abnormalities

induced by tumors may affect the status of different

nutrients. Radiation, surgery, and drug therapies each

have consequences which predispose the patient to

potentially serious nutrition problems.

Vision Disorders

0018Aging is associated with extensive postsynthetic

modifications to eye lens proteins resulting in aggre-

gation with eventual polymerization and precipita-

tion to form opacities or age-related cataracts. The

prevalence of cataract increases with age, reaching

about 50% in people 75–85 years old; prevalence

rates are higher if early lens changes are included in

the calculation. Oxidation of lens proteins is highly

correlated with cataract and research studies provide

evidence for a close relationship between cataracto-

genesis and nutrition. An elevated status of dietary

antioxidants is strongly correlated with a lower inci-

dence of cataract. Ascorbic acid concentration in the

lens can be as much as 30 times that in plasma but

decreases in aged and cataractous lens. Vitamin E is

associated with protection against oxidative insults

and glutathione-dependent antioxidant reactions are

compromised in the lens with age and cataracts. The

effect of other nutrients, e.g., folic acid, riboflavin,

vitamin B

, taurine, and tryptophan, has been exam-

ined but evidence supporting their protective role

against cataractogenesis remains limited. Intake of

the xanthophyll carotenoids, lutein and zeaxanthin,

is inversely correlated with the incidence of cataract

and cataract extractions.

0019Age-related macular degeneration (AMD) is the

leading cause of irreversible blindness among older

adults. The retina is rich in highly polyunsaturated

fatty acids, particularly docosahexaenoic acid, and

thus vulnerable to lipid peroxidation. This situation

is compounded by exposure to light, high oxygen

tension, and high concentrations of retinol. The

macula contains a full complement of antioxidant

defenses but is unusually rich in lutein and zeax-

anthin, which provides its yellow pigment and optical

density, and absent in b-carotene and lycopene. Ob-

servational studies indicate that generous intakes of

lutein and zeaxanthin are associated with a signifi-

cant reduction in risk of AMD. Zinc plays a role in the

metabolic function of several antioxidant enzymes in

the chorioretinal complex and limited evidence sug-

gests increased zinc intake may benefit visual acuity

in AMD patients.

Coronary Heart Disease

0020The progressive focal narrowing of coronary arteries

by atherosclerosis, beginning as early as age 10, leads

ELDERLY/Nutritionally Related Problems 2025

to an inadequate circulation of blood in local areas of

heart muscle. These changes can result in angina

pectoris, myocardial infarction (heart attack), and

sudden death in older adults. These and related dis-

orders are termed coronary heart disease (CHD) and,

in western countries, account for more deaths annu-

ally than any other group of diseases. The prevalence

of CHD is greater among men than women and in-

creases markedly in those over 65 years of age. Med-

ical interventions and changes in lifestyle during the

past two decades have reduced the age-corrected

death rate from CHD by about 40%; however,

without a further reduction in risk factors and/or an

improvement in treatments, CHD prevalence and

incidence will increase in the future because of the

aging of the population. The causes of CHD are

multifactorial and include cigarette smoking, high

blood pressure, obesity, and high blood cholesterol

(hypercholesterolemia).

0021 The relationship between diet, lipoprotein metab-

olism, atherogenesis, and CHD has been defined by

extensive scientific investigations conducted during

the last 75 years. This work indicates a strong, con-

tinuous, and graded relationship between total blood

cholesterol levels, the severity of atherosclerosis, and

risk for CHD. Dietary saturated fat and cholesterol

raise total blood cholesterol and low-density lipo-

protein (LDL) cholesterol levels; LDL is the major

atherogenic lipoprotein and accounts for most of the

CHD risk associated with elevated plasma total chol-

esterol. Polyunsaturated and monounsaturated fat

lowers total blood cholesterol and LDL cholesterol

levels when substituted for saturated fat in the diet.

High-density lipoprotein (HDL) is considered to pro-

tect against CHD and is associated with female sex,

estrogen use, exercise, moderate alcohol consump-

tion, and weight loss.

0022 Diet is considered the cornerstone of therapy to

reduce borderline (200–239 mg dl

1

) and high-risk

(240 mg dl

1

) blood cholesterol levels whether or

not drug therapy is eventually added to the regimen.

Dietary guidelines to reduce risk of CHD include

recommendations of nutrient intake as a percent of

total calories of less than 30% from fat (less than

10% from saturated fat, up to 10% from polyunsat-

urated fat, and 10–15% from monounsaturated fat),

50–60% from carbohydrates, and 10–20% from

protein. Total calorie intake should be designed to

achieve and maintain desirable weight. In addition,

daily cholesterol intake should be less than 300 mg.

Individuals at very high risk of CHD should further

reduce saturated fat and cholesterol intake. Adher-

ence to these dietary guidelines has been proven to

lower blood cholesterol by 10–25%. Elevated plasma

homocysteine is an independent risk factor for CHD.

Homocysteine concentrations can be reduced by

increasing the intake of folic acid, vitamin B

,and/

or vitamin B

; however, prospective studies demon-

strating a decreased incidence of CHD with B vitamin

interventions have not been completed. Supplemen-

tation with vitamin E and/or fish oil may play a role in

the primary and secondary prevention of CHD but

the results of clinical trials are equivocal.

Diabetes

0023Type 2 diabetes, formerly called noninsulin-depend-

ent diabetes mellitus, accounts for about 90% of

all cases of the disease. The onset of type 2 diabetes

is gradual (with no or mild symptoms), usually

appearing in midlife among people who are over-

weight or obese. Although type 2 diabetics display

normal pancreatic histology, secrete insulin in re-

sponse to glucose ingestion, and have normal to

high levels of circulating insulin, they are less able to

use this insulin (insulin resistance). Type 1 diabetes,

formerly called insulin-dependent diabetes mellitus, is

characterized by an absolute deficiency of insulin

caused by b-cell destruction of the islets of Langer-

hans in the pancreas. Type 1 diabetes usually begins

abruptly in adolescents and young adults of normal

body weight. No method has been identified which

prevents type 1 diabetes and these patients require

insulin administration for survival. Genetic predis-

position appears to play an important role in both

type 1 and type 2 diabetes. The specific cellular basis

of hyperglycemia and related metabolic abnormal-

ities in type 2 diabetes is not yet clear, although

three defects appear to be involved: a diminished

pancreatic b-cell response to glucose; a reduced syn-

thesis or function of cellular receptors for insulin; and

an impaired ability to utilize glucose following bind-

ing to cellular receptors. Clinical complications of

diabetes include heart disease and stroke, kidney dis-

ease, blindness, nontraumatic leg and foot amputa-

tions, and death.

0024Dietary therapy is considered the key to the man-

agement of type 2 diabetes. Obesity is strongly asso-

ciated with the onset and severity of type 2 diabetes

with more than 80% of patients being more than

15% in excess of their desirable body weight at the

time of diagnosis. Weight loss reduces insulin resist-

ance as well as fasting and postprandial blood glucose

levels in overweight diabetics. Dietary recommenda-

tions for the management of diabetes include: 50–

60% of total calories as carbohydrate (emphasizing

complex carbohydrates and water-soluble fiber); de-

creased protein in those with renal insufficiency; 30%

or less of total calories as fat (with reduced intake of

saturated fat); and limited alcohol intake (restricted

entirely in poorly controlled diabetes). Limited and

2026 ELDERLY/Nutritionally Related Problems