Author
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Lukaski, Henry |
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Submitted to: The American Journal of Clinical Nutrition
Publication Type: Review Article Publication Acceptance Date: 1/23/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Individuals who seek to promote and enhance health tend to adopt behaviors that include selection of a proper diet and participation in physical activity. With increased awareness of the mutual benefit of these activities on well-being, there is also a growing awareness of the beneficial role that mineral elements play in promoting health. To maximize these benefits, some individuals rely on supplements of magnesium, zinc and chromium. Although these mineral elements have established biological roles that promote health and support physiological functions required for physical performance, there is no compelling evidence that consumption of supplements of these minerals will benefit health or performance of individuals who consume diets containing adequate amounts of these minerals. There is clear evidence that excessive consumption of magnesium, zinc and chromium supplements by individuals with adequate dietary intakes of these minerals can induce adverse biological effects. Furthermore, studies in which athletes consuming nutritionally adequate diets and supplemented with vitamins and minerals failed to document any improvement in physical performance. One may conclude that consumption of a balanced diet containing a variety of foods is the appropriate approach to meeting the nutritional needs of all people regardless of physical activity level. This information will be useful to dietitians and nutritionists who advise physically active individuals of all ages. Technical Abstract: Magnesium, zinc and chromium are mineral elements that are required in modest amounts to maintain health and optimal physiological function. For physically active people, adequate amounts of these micronutrients are needed in the diet to ensure the capacity for increased energy expenditure and work performance. Most physically active individuals consume diets that provide amounts of magnesium and zinc to meet population standards. Women tend to consume these minerals in amounts that are less than recommended, in part because they eat less food than men. Inadequate intakes of magnesium and zinc are reported for some individuals participating in activities that require body weight standards. Dietary chromium is difficult to estimate because of a lack of appropriate reference data bases. Acute intense activity results in short-term increases in urine and sweat losses of minerals that apparently diminish during recovery in the days after exercise. Supplemental magnesium and zinc apparently improve strength and muscle metabolism. However, evidence that the observed effect is related to impaired nutritional status or a pharmacological effect is lacking. Chromium supplementation of young men and women does not promote muscle accretion, fat loss or strength gain. Physically active individuals with concern about meeting guidelines for nutrient intake should be counseled to select and consume foods with high nutrient densities rather than to rely on nutritional supplements. The indiscriminate use of mineral supplements can adversely affect physiological function and impair health. |
