Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: October 4, 1996
Publication Date: N/A
Technical Abstract: As adult humans age, characteristic changes in body composition, physiological function and dietary intake of essential nutrients occur. Epidemiological studies suggest that decreases in skeletal muscle mass are associated with impaired strength, functional capacity and quality of life, and increased morbidity. Also, nutritional surveys indicate that many elderly consume less than recommended amounts of essential nutrients. The hypothesis that correction of inadequate nutrient intake ameliorates age-dependent deficits in physiological function has been examined for some nutrients. Women aged 66 to 79 y were fed diets containing either low (one-half the RDA) or adequate (RDA) dietary protein for 12 wk. Low protein intake was associated with negative nitrogen balance, decreased fat-free mass and impaired muscle function. No alterations in nitrogen balance, body composition or muscle function were seen in the adequate protein group. Supplemental vitamin E (727 mg alpha tocopherol/d for 48 d) provided to young and older men significantly reduced exercise-induced skeletal muscle damage. Importantly, the beneficial effect of vitamin E was more pronounced in the older than the younger men. The effects of altered magnesium intake on muscle magnesium concentration and energy expenditure during exercise were examined in postmenopausal women. As compared to a diet containing low magnesium (90 mg/2000 kcal/d) content, adequate magnesium (290 mg/2000 kcal/d) significantly increased skeletal muscle magnesium and increased the efficiency of energy production during ergocycle exercise. These examples emphasize the importance of adequate dietary nutritional intake to optimize physiological function in the elderly.