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ARS Home » Plains Area » Grand Forks, North Dakota » Grand Forks Human Nutrition Research Center » Dietary Prevention of Obesity-related Disease Research » Research » Publications at this Location » Publication #115906
Title: RESPONSE OF LIVER AND HEART TRACE ELEMENTS IN RATS TO THE INTERACTION BETWEEN DIETARY ZINC AND IRON

Author
item ZASLAVSKY, BORIS - 5450-20-00
item Uthus, Eric

Submitted to: Biological Trace Element Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/21/2002
Publication Date: 8/1/2002
Citation: Zaslavsky, B., Uthus, E.O. 2002. Response of liver and heart trace elements in rats to the interaction between dietary zinc and iron. Biological Trace Element Research. 88(2):165-183.

Interpretive Summary: Nutrients can interact beneficially or antagonistically with other nutrients. For example high dietary zinc can decrease copper absorption from the diet. Although an interaction between dietary zinc and iron occurs, it has not been widely studied. Thus, this research examined the nutritional importance of this interaction by using results from laboratory rats that were fed diets containing various amounts of iron and zinc. The study investigated the effects of graded dietary iron and zinc on liver and heart trace element concentrations and the usefulness of these changes to predict the original dietary concentrations of iron and zinc. The responses studied were the effect of dietary iron (or dietary zinc) on single trace element concentrations in liver or heart, and the effect of dietary zinc (or dietary iron) on combined (grouped) trace element concentrations in liver or heart. The results show that grouped parameters are better for making predictions of dietary intakes of nutrients. This paper presents a new methodical approach to study the interaction analysis and presents a method of identifying grouped parameters that may be useful as status indicators (i.e., predictors of dietary intake of zinc and iron). This is a novel approach that may be used to determine dietary intake of nutrients and whether or not a person is getting too little, enough, or too much, of a nutrient.

Technical Abstract: An analysis of the interaction between dietary iron (Fe) and zinc (Zn) was performed by using data from Sprague-Dawley rats in a 5 x 4 fully- crossed factorially arranged experiment. The concentrations of 9 trace elements from liver and 10 from heart were determined and subjected to diverse statistical analyses and were classified by their response to the interaction between dietary Fe and Zn. The interaction was studied by using analysis of variance, discriminant analysis, and logistic regression to determine the direction of interaction - that is, did dietary Fe affect dietary Zn or did dietary Zn affect dietary Fe? The use of discriminant analysis allowed for using multiple parameters (rather than a single parameter) to determine possible interactions between Fe and Zn. Thus, two main levels of interaction were studied - the separate response of each tissue mineral and the response of some grouped minerals. The responses studied were the effect of dietary Zn on tissue trace element parameters, the effect of dietary Fe on the parameters, the effect of dietary Zn on combined (grouped) parameters, and the effect of dietary Fe on combined parameters. As determined by ANOVA, only three individual trace elements - liver Fe, Cu and Mo - were significantly affected by the interaction between Fe and Zn. However, a broader interaction between Fe and Zn is revealed when groups of, rather than single, trace elements are studied. For example an interaction between dietary Fe and Zn affects the weighted linear combination of heart Ca, Cu, K, Mg, Mn, P, and Zn. This paper presents a new methodical approach to the interaction analysis and presents the hypothesis that grouped parameters may be useful as status indicators.