Calorie Restriction and Healthy Aging: Part 2
Last month we explored calorie reduction and it's benefits on healthy aging. There are, however, some limitations to calorie restriction and it's prolonged practice. This month we will look at the pros and cons of CR from a scientific standpoint and see what current research has in terms of recommendations.
Ultimately, prolonged CR is a difficult intervention to implement. Researchers contend it is impossible to adapt long term CR in modern society. If not done appropriately, CR can pose detrimental health effects, including anemia, weakness, dizziness, lethargy, irritability, muscle wasting, and bone demineralization. Specifically, in elderly individuals of healthy weight, weight loss may be harmful, especially in those with frail conditions. Underweight individuals of advanced years who contract a winter virus or flu may not have the immunity and nutrient stores to fight them. And if an individual loses a few pounds, it could result in a downward health spiral. Several studies reveal that overweight status may actually result in better outcomes in elderly people. Research also shows that CR during the younger years holds true health promise and should not be discredited.
So there seems to be some conflicting research. In essence, too few studies have been conducted that identify nutrient requirements, healthy weight, and body mass changes in the geriatric population. There is inadequate research on the effects - positive or negative- of CR in the elderly and very limited studies to direct nutritional care for the aging. Even the Dietary Reference Intakes and Recommended Dietary Allowances from the Food and Nutrition Board, Institute of Medicine, outline nutrient requirements only to about 70 years of age and are not effective in assessing nutrient needs of older groups. This internationally recognized and evidence based tool does not provide guidance for people living in their eighth, ninth, or even tenth decades of life.
Current data suggests that CR can exert beneficial effects on the factors involved in the pathogenesis of age associated chronic disease and life expectancy. The research indicates that in healthy middle aged participants, CR can result in reduced risks of life threatening diseases such as cancer, diabetes, and heart disease. Consuming fewer calories can potentially improve overall health span, which are the years during which an individual is healthy and remains free from disease. It may also lead to increased longevity by the reduction of DNA damage and oxidative stress. Additional studies are needed to validate this, as human studies in this are are limited and of short duration.
While research supports lower calorie consumption and a below average body weight throughout life to reduce chronic disease and increase longevity, there are scant data supporting the beneficial effect of CR in elderly people. In fact, having energy reserves during times of stress, illness, and trauma can provide a protective effect and reduce mortality in this population. Multiple studies show that being overweight is related to better outcomes in the elderly and excessive weight loss in elderly people is associated with poor clinical outcomes.
Additional research and policy development to establish healthy weights and nutrient requirements for older adults over the age of 70 are needed prior to making firm recommendations to this population. Assessment, education, and monitoring by a registered dietitian nutritionist with specialized knowledge in aging can be beneficial to decrease the risks of chronic disease and to promote longevity.
In conclusion, perhaps a more realistic approach is to encourage a small reduction in caloric intake and to avoid significant fluctuations in body weight through old age.
|Nora DeVoe is a Gerontologist specializing in Eldercare and Caregiver issues. She may be reached at (716) 667-7299.|
Dr. Nora is a ....