Author
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Lukaski, Henry |
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Submitted to: Book Chapter
Publication Type: Book / Chapter Publication Acceptance Date: 5/31/1999 Publication Date: N/A Citation: N/A Interpretive Summary: Although many factors are known to influence utilization of minerals in the diet, there is little information about the role of fat, a significant component in the diets of many Americans, in the metabolism of minerals. Within limits, dietary fat assists in the uptake of calcium and magnesium, but the effects are limited by large intakes of saturated or animal fat. Large amounts of polyunsaturated fats, generally from vegetable sources, lower the amounts of copper and zinc in animal tissues such as the liver, and increase the loss of zinc from the body. Some saturated fat, such as that from beef and lard, apparently increase the body's ability to use iron from the diet. It is not well understood at present how dietary fat affects mineral use in the body. It may be, however, that fat affects mineral uptake at the cell by influencing transport across the cell wall or membrane. This work is important because it will help integrate our knowledge of factors positively affecting human mineral status. Technical Abstract: The effects of type and amount of dietary fat on calcium, magnesium, copper, zinc and iron absorption, retention and tissue distribution in animals and humans are reviewed. The effects of fat on calcium and magnesium utilization are not clear, but children apparently are affected differently than adults. Zinc and copper concentration in organs of animals is significantly reduced by diets high in polyunsaturated fat intake. Iron status of iron-deficient animals fed saturated fat improves. Human retention of dietary iron also responds positively to dietary saturated fat. The mechanism of action of dietary fat on mineral metabolism is not well defined. Polyunsaturated fat apparently affects membrane transport function and thus influences uptake of minerals. |