Don't Forget the Water! Peggy K. Yen, RD, M P H

Getting plenty of water every day is an important nutrition guideline for older adults. In the newly released Food Guide Pyramid for Older Adults, developed by the Amer ican Dietetic Association and shown in Figure 1, water is said to be the "true base of the pyra- mid of healthy eating." Drinking 6 to 8 cups of water a day is adequate for elderly people to replace normal, daily fluid loss. Solid food con- tributes another 2 to 4 cups of water. Pasta is about two-thirds water, for example; fruits and vegetables contain up to 95% water by weight.

What To Drink? Water, fruit and vegetable juice, milk, and

caffeine-free beverages like herbal tea and decaffeinated coffee are the best choices for elders. Caffeine in beverages acts like a diuret- ic and leads to fluid loss. On the plus side, reg- ular tea contains antioxidants that may be use- ful in cancer and heart disease prevention.

Because getting necessary nutrients be- comes more difficult with age, beverages cho- sen to meet elders' fluid requirements should contribute more than just calories. Milk and fruit and vegetable juices supply important vit- amins, minerals, and, in the case of milk, pro- tein. With these beverages, older adults can get needed fluid while consuming recommended servings from the food guide pyramid.

The latest products on the beverage mar- ket may contain herbal additives, such as echi- nacea, ginseng, and ginkgo biloba. As an incen- tive for older adults to drink more fluids, this addition makes them useful. But these bever- ages usually contain sugar and therefore extra calories and may not supply needed nutrients. Some evidence has emerged from clinical trials that ginkgo may promote slight improvement

or slow down loss of functioning in patients with Alzheimer 's disease.

On the other hand, a report in the New England Journal of Medicine ~ describes a 70- year-old man who took 80 mg of ginkgo daily along with aspirin as r ecommended to pre- vent hear t disease. Af te r a week of this regimen, he developed bleeding from the iris of his eye, which stopped when he stopped taking the ginkgo. Caution is advised in consuming h e r b - s u p p l e m e n t e d beverages because no s tandardizat ion exists for additives to ensure that the active form of an herb is used and in sufficient amounts to benefit older adults, and incompatabi l i ty with prescribed medications is possible.

ii table juice, milk,

and caffeine.free

beverages like

and

coffee

hoices

s,

Aging Thirst Mechanisms Feeling thirsty means the body already has

lost at least 1 or 2 cups of water. Older adults cannot rely on thirst to guide their drinking habits. The decreased thirst response of aging keeps elders from drinking to make up a fluid deficit. Certain conditions, such as stroke, fur- ther decrease thirst response in elders. This decreased response, in combination with aging kidneys that conserve less water, means older adults can become dehydrated relatively easily.

Geriatric Nursing Volume 19, Number 5 295

The Problem of Dehydration Dehydrat ion, often a result of infection, frequently leads to

hospitalization of older nursing home residents. Nurses are well- trained to look for signs of dehydration, which are listed in Table 1. Dehydrat ion can cause constipation, postural hypotension, delirium, and kidney problems. Immobil i ty or use of restraints can keep patients f rom reaching fluids even when their thirst mecha- nisms are working. In a report on the nutrition knowledge of care- givers, ~ almost a third of the respondents said they rarely encour- aged the elders in their care to drink more water.

Assessing hydration in older adults can be problematic. Physical examination is not a reliable way to assess mild dehydra- tion. A method using bioelectrical impedance technology seems

::~Food Guide Pyramld :

Table 1. Warning Signs of Dehydration

* Dry mouth, tongue, or nasal membranes

• Confusion or agitation

• Constipation

• Dark, concentrated urine or decreased output

• Weakness, dizziness

promising and relat ively easy to use. Resistance (impedance) to a weak electrical current is related to total body water and lean body mass. The bioelectr ical impedance method is used primarily to assess the percent of body fat in fitness and weight-loss settings. However , geriatr icians have applied this method to measure hydration status in elderly nursing home patients. 3 Al though a single measu remen t is not part icular ly accurate, repeated measurements are helpful in assess- ing changes in fluid balance, particularly when weighing patients daily is difficult or cumber- some.

REFERENCES

1. Rosenblatt M, Mindel J. Spontaneous hyphema associated with ingestion of ginkgo biloba extract. N Engl J Med 1997;336:1108.

2. Ryan C. Caregivers of the elderly: lack of nutrition knowledge. J Nutr Elderly 1997;17(2):35-44.

3. Rikkert M, Deurenberg R Jansen R, ran'tHor M, Hoefnagels W. Validation of multifrequency bioelectrical impedance analy- sis in detecting changes in fluid balance of geriatric patients. J Am Geriatr Soc 1997;45:1345-51.

PEGGY K. YEN, RD, MPH, is a nutrition consultant with Cardiovascular Health and Nutrition, Community and Public Health Administration in the Maryland Department of Health and Mental Hygiene in Baltimore.

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