Heather H. Keller, RD, PhD, Associate Professor, Dept. Family Relations and Applied Nutrition, University of Guelph, Guelph, ON.

Although the prevalence of malnutrition and, specifically, undernutrition are unknown among Canadian seniors, nutritional risk has been identified as a common problem. As nutritional risk can lead to malnutrition and all of its sequelae, efforts are needed to identify nutrition problems early in their course to improve the quality of life of seniors. The following article provides a variety of approaches for identifying nutritional problems, from simple indicators to a simplified and standardized nutritional assessment. Suggestions also are provided on how the practitioner can seek assistance with intervening and helping the senior to overcome these problems.
Key words: nutrition, older adults, screening, intervention, risk, weight.

Taking a 'stroll' through a geriatric unit, either in acute care or rehabilitation, one is struck by how many of the patients seem undernourished. This highlights the need for clinical dietitians as part of the multidisciplinary team required for effective geriatric care. Thankfully, most elderly people are not admitted to a geriatric unit, and their dietary issues are more similar to those facing the population at large.

Clearly, it is much better to eat in a healthy manner to prevent functional decline than it is to engage in heroic 'salvage' operations when catastrophic illness strikes (see the article 'Supporting seniors to age well with healthy eating' in this edition). However, the biggest issue facing most Western populations is not under nutrition, but rather excess weight. Should the same guidelines for overweight apply to those over 65 as have been developed in middle-aged populations? I am somewhat comforted, as I note my expanding waistline, by an article in last year's Archives of Internal Medicine¹ that suggests modest degrees of overweight (BMI 25-27) in the elderly do not increase cardiac and all cause mortality (although frank obesity does).

Even more interesting than total energy intake, is the content of the diet. Clearly elderly patients can suffer from specific nutritional deficiencies, such as Vitamin D or zinc (see article in this issue 'Zinc Deficiency in older adults' by AlAteequi and Allard). However, healthy people of all ages are thinking beyond simple dietary deficiency and wondering about the optimal dietary intake. In the current jargon, you are what you eat. This edition contains an article on diet and prostate disease and, of interest to both men and women, one on the relationship of Vitamin E to dementia (see article by Basran and Hogan in this edition). We usually think of vitamin E as a possible treatment of Alzheimer disease, but the antioxidant actions of vitamin E have long been postulated to be of benefit to the aging brain even before dementia occurs. Two recent studies in the Journal of the American Medical Association provide some evidence for the protective effects of vitamin E (and perhaps vitamin C).^2,3 Of course, epidemiological studies do not prove cause and effect; rather, they suggest appropriate directions for future treatment studies. What I found interesting is that while in both of these studies the relative risk of dementia was decreased by high dietary vitamin E (and in the first study, but not the second, high dietary vitamin C), supplements of vitamin E seemed to have no benefit.

Why might this be? The most obvious answer is that those who take Vitamin E supplements are different from those who do not; specifically, they might choose to take vitamin E when they detect early memory problems that predict future dementia. As well, vitamin E has only become popular as a supplement recently; thus, those who take their vitamin E as a supplement might not have had as long an exposure to its benefits as have those with a life-long, high dietary intake. It might also be that vitamin E is simply a surrogate for another dietary constituent that is actually of benefit. The fact that the two studies are discordant in their results with vitamin C is also cause for concern.

Regardless of the true relationship between vitamin E and dementia, there is no doubt that this edition of Geriatrics and Aging will provide a great deal of 'food for thought'.

References

1. Heiat A, Vaccarino V, Krumholz HM. Arch Intern Med. 2001;161:1194-203.
2. Englehart MJ, Geerlings MI, et al. JAMA 2002;287: 3223-9.
3. Morris MC, Evans DA, et al. JAMA 2002;287:3230-7.

Lilia Malkin, BSc

Nutritional status has been widely acknowledged to play a key role in the maintenance of health and recovery from disease. Malnutrition has been linked to increased morbidity and mortality, while nutritional support through enteral or parenteral routes has been demonstrated to contribute to reduced morbidity and shorter hospital stays.¹ It is also recognized that while several vitamins and minerals are essential to the human body, nutrient intake requirements do vary across age groups. Unfortunately, it may be difficult to obtain the necessary nutrients from food products alone. The challenge of maintaining a well-balanced diet with appropriate caloric and nutritional intake is made more difficult in the ill and the elderly, resulting in malnutrition. This article will focus on the unique nutrient requirements of the geriatric population and the potential contribution of oral nutritional supplements in ensuring a well-balanced diet among both community-dwelling and hospitalized members of this age group.

Nutrient requirements
As the body grows older, it undergoes a multitude of physiologic alterations, resulting in changes in macro- and micro-nutrient requirements.

Barry Goldlist, MD, FRCPC, FACP

There is more and more evidence accumulating in recent years that demonstrates the critical importance of nutrition in the elderly. The negative consequences of being overweight have long been known. Much of the modern 'pandemic' of type II diabetes mellitus is secondary to this. As well, hypertension and hyperlipoproteinemias are related to obesity. Recent evidence has confirmed the long suspected relationship between arthritis of the knee and excess weight. Despite this, the average weight of North Americans continues to rise. My personal belief is that this does not simply reflect a lack of personal self-discipline, but rather a societal structure that constrains physical activity in day-to-day existence. Irregular trips to the gym are no substitute for walking each day, even if only to the bus stop. Our cities in North America, with their sprawling suburbs, seem designed specifically to discourage walking and encourage driving. A rethinking of how we design our living spaces might help in controlling the occurence of obesity.

We understand even less about the causes of under-nutrition in old age. Is it a consequence of disease and decline, or is it a factor that causes functional decline? Certainly the causes of weight loss in old age are almost always multifactorial. The various factors range from poor dentition, loss of ability to smell, the effects of drugs, to specific disease processes, such as cancer. Eating is also an intensely social process, and isolated seniors are particularly at risk for under-nutrition. Regardless of whether under-nutrition is the 'chicken or the egg', once an elderly person becomes ill, careful attention to nutritional issues is often the key to ultimate functional recovery. Thus, in any geriatric service, the clinical dietitian is a key member of the team. For any physician following elderly patients in their own practice, the easiest way to detect problems at an early stage is to carefully record the patient's weight at regular intervals. This is particularly important in nursing homes, where weights should be recorded on a monthly basis. In the USA, intense research interest has been focused on this issue, particularly on the fact that protein loss seems to predominate in some patients. The resulting loss of muscle mass has been called 'sarcopenia', and is clearly a factor in functional decline.

It is ironic, that as a geriatrician, even though I have seen wonderful therapeutic advances in care of the elderly, the best strategy for maintaining quality of life in old age, continues to consist of regular exercise and good eating habits.

Cancer and Nutrition: Be Cautious When Making Dietary Recommendations

Eleanor Brownridge,
Registered Dietitian

While a number of major dietary components--including fat, total energy, salt, red meat and alcohol--have been implicated as contributing to specific cancers, current case-control and cohort studies do not support some of the predominant hypotheses that are influencing Canadian eating habits. A major reason for the current level of certainty is the challenges inherent in nutrition epidemiology.

Diets are extremely complex. Nutrients are found in a multitude of foods, and their absorption and activity is influenced by other dietary components eaten at the same time. People change their eating habits over time and we have no idea as to the relevant latency period for various diet-related effects.

Eleanor Brownridge, RD, FDC

The nutrition priorities of the elderly (over age 75) go against the grain of mainstream nutrition messages believes Dr. Katherine Gray-Donald, Associate Professor at the School of Dietetics and Human Nutrition, McGill University in Montreal. "These people shouldn't be worrying about fat and cholesterol. Rather than tons of vegetables and fruit and skim milk, they need omelettes, milk shakes and cream soups."

"We've been able to show that for the homebound elderly declining body weight is a predictor of mortality," says Dr. Gray-Donald. "People who lose weight die sooner."

Moreover, a recent 5-year mortality study of 4300 nonsmoking men and women, aged 65 to 100 years, indicated that being overweight later in life does not pose a significant health risk.¹ Rather the risks associated with significant weight loss should be the primary concern.

Traditionally physicians have asked patients: "Have you unintentionally lost ten pounds or more in the past year?" But even intentional weight loss in an elderly person suggests nutrition problems. Because of low energy needs, it is very difficult for an elderly person to lose weight by dieting and still maintain adequate nutritional status.

By the time a 10-pound weight loss has occurred it may be too late to reverse muscle deterioration. Dr.

Barry Goldlist, MD, FRCPC, FACP

Ever since the landmark article by Fries in the 1980 New England Journal of Medicine, entitled 'Aging, natural death, and the compression of morbidity,' investigators, elderly people, and probably many younger people, have wondered whether the progressive frailty and dependency traditionally associated with aging are, in fact, inevitable. Preventive medicine, which originally meant preventing death early in life, is now being applied to preventing disability in the elderly. There is persuasive evidence presented by the MacArthur Foundation Study of Aging in America that the lifestyle choices we make are important factors in how we age. This information is clearly and effectively presented by Rowe and Kahn in the 1998 publication, 'Successful Aging.' They make a persuasive argument that while most of the chronic degenerative diseases of aging have a significant genetic basis, manipulating environmental factors can still be incredibly important.

Rowe and Kahn present their most persuasive argument in touting nutrition and physical exercise in preventing age-related frailty. My reading of the literature over the past few years is that although any exercise is better than no exercise, very vigorous exercise is better than moderate exercise. While early detection of specific diseases is important as well (e.g. cancer screening, diabetes detection, hypertension detection and treatment), I for one am firmly convinced that exercise and diet will provide the 'biggest bang for the buck.' Although lifelong commitment to preventive health care is the optimum, it seems like there is benefit in vigorous exercise and proper nutrition regardless of the age at which it is started.

The maintenance of normal cognitive function with aging is a much more difficult issue. We do know that higher levels of education are associated with less cognitive decline in old age, but it is unsure if there is any causal link. Certainly maintenance of good physical health will help maintain good mental health as well. There is really no evidence at the present time that 'mental gymnastics' such as crossword puzzles, or specific diets (e.g. rich in antioxidants), will help in maintaining cognitive function.

In the textbook 'Principles of Geriatric Medicine and Gerontology,' Professor Hazzard writes a chapter on preventive gerontology that emphasizes the lifelong health practices that promote successful aging. It seems that it is never too early to plan for a healthy old age. Fortunately, it is also never too late to start.