Supporting Seniors to Age Well with Healthy Eating

Nutrition is a key factor in successful aging. Eating well can help older adults maintain their health and independence. A healthy, well-nourished senior is more likely to feel good, stay well and be able to contribute as a vital member of their family and community.

Many seniors are interested in healthy eating and will make significant changes in their food choices in an effort to maintain and improve their health.¹ Dietitians offer the following sound advice to older adults motivated to stay well by eating well:

• Emphasize whole or enriched grain products such as bran cereals, multigrain bread, barley and brown rice;
• Drink plenty of fluids to assist digestion and prevent dehydration;
• Add colourful fruits and vegetables to stimulate appetite and provide essential vitamins and minerals;
• Help strengthen bones by improving intake of calcium and Vitamin D. Choices include milk, yogurt and cheese;
• For high-quality protein, include foods such as beef, poultry, fish, eggs, tofu and legumes;
• Choose lower fat foods more often, add less fat in cooking and at the table;
• Eat and drink enough to maintain a healthy weight.

Most importantly, seniors are encouraged to stay active and make healthy eating a pleasurable part of their daily lives.

For many older adults, physiological, functional and environmental realities of aging interfere with healthy eating.

Dietary Measures to Prevent Prostate Cancer

June M. Chan, ScD, Assistant Adjunct Professor, Departments of Epidemiology & Biostatistics and Urology, University of California, San Francisco, CA, USA.

Prostate cancer is the most commonly diagnosed cancer and is second only to lung as the most fatal cancer among men in the United States. It is the ninth most common cancer in the world, with higher rates predominating in North America, Europe and Australia, and lower rates reported in Hong Kong, Japan, India and China. The main non-modifiable risk factors include age, race and family history.

The incidence of prostate cancer increases exponentially with age, with men age 75-79 experiencing an incidence rate more than 100-times greater than that of men age 45-49 (age-specific prostate cancer incidence rate for men age 75-79 = 1400/100,000 person-years; for men age 45-49 = 11/100,000 person-years).¹

African Americans have the highest recorded age-standardized rates in the world, estimated at 137 cases per 100,000 persons in 1997 according to Surveillance, Epidemiology, and End Results (SEER) data.² In contrast, the rate among Caucasians in the U.S. was 101/100,000. Europeans tended to have rates in the range of 20-50 cases/100,000.

Zinc Deficiency in the Elderly

Nabeel AlAteeqi MD, FRCPC and Johane Allard MD, FRCPC
University of Toronto, Toronto, ON.

Introduction
Zinc is one of the essential micronutrients, and plays an important role in human nutrition and health. In 1961, Prasad first recognized zinc deficiency as the cause of dwarfism and hypogonadism among iron-deficient adolescent Iranian village boys.^1,2

Zinc deficiency occurs in individuals and populations with diets low in sources of readily bioavailable zinc, such as red meat, and high in unrefined cereals that are rich in phytate. The elderly population is potentially vulnerable to zinc deficiency because of decreased intake of food energy, protein, vitamins and minerals, and increased intake of carbohydrates.^3,4

In this review, we discuss the importance of zinc to humans, as well as the causes, clinical features and management of zinc deficiency in the elderly population.

Importance of Zinc
Zinc is an essential mineral, present in most systems of the human body, and plays a role in stabilization of cell membranes, tissue regeneration and protein synthesis. It also serves as a structural component of at least 70 metalloenzymes. Examples of zinc metalloenzymes are carbonic anhydrase, alkaline phosphatase, alcohol dehydrogenase and zinc-copper superoxide dismutase.

In addition, zinc is needed for growth, normal development, DNA synthesis, RNA conformation, immunity, neurosensory function and other important cellular processes.

Vitamin E and Alzheimer Disease

Jenny F.S. Basran, BSc, MD, and David B. Hogan MD, FACP, FRCPC
Division of Geriatric Medicine, University of Calgary, Calgary, AB.

Introduction
Recently, there has been growing interest in the use of vitamins for the treatment of various health conditions. One study has estimated that 35-54% of older Canadians take some form of vitamin or mineral supplement.¹ Oxidative stress has been theorized to be an important contributor to select conditions, particularly those involving the cardiovascular and central nervous systems. Vitamin E is the only fat-soluble, chain-breaking antioxidant found in biological membranes⁴ and, therefore, has been investigated for its use in the treatment of ischemic cardiovascular disease in recent landmark studies such as the Heart Outcome Evaluation Study (HOPE)² and Heart Protection Study (HPS).³

How Does Vitamin E Work?
Vitamin E is a generic term for chemical derivatives of tocopherol and tocotrienol.⁵ There are eight naturally occurring forms, but only a-tocopherol is found in human plasma, has the highest bioactivity and is the form used for medicinal purposes. a-tocopherol is found naturally in vegetable oils, almonds, sunflower seeds, walnuts, sweet potato, liver, wheat germ and egg yolk.⁶ Synthetic forms are available as vitamin capsules and in fortified foods.

Nutrition in the Elderly: Food for Thought

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.