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United States Department of Agriculture

Agricultural Research Service

Title: Level of Dietary Iron, Not Type of Dietary Fat, Is Hyperlipidemic in Copper-Deficient Rats

Authors
item Fields, Meira
item Lewis, Charles

Submitted to: Journal of American College of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 21, 1999
Publication Date: N/A

Interpretive Summary: Both cholesterol and triglycerides are blood risk factor metabolites associated with heart disease. Therefore, we are advised to reduce the consumption of nutrients which have the potential to elevate these risky compounds. One of these undesirable nutrients are saturated fats. We are recommended to substitute saturated fat with unsaturated fat because unsaturated fat does not raise blood lipids. Based on our recent studies we noticed that high levels of dietary iron have the potential to elevate the concentrations of cholesterol and triglycerides in blood. We asked whether the consumption of high levels of iron will overrule the protective effects of unsaturated fat. When rats were fed diets which contained high levels of iron, they exhibited high levels of blood triglycerides. When the diets consumed were high in iron but low in copper they caused an elevation of blood cholesterol even when the diets contained unsaturated fat. Data clearly show regardless of the type of dietary fat, levels of dietary iron are responsible for elevating blood risk metabolites associated with heart disease. Nutritionists, health and medical professionals should benefit from these data and should be aware of the undesirable effects of the consumption of high levels of dietary iron.

Technical Abstract: This study was conducted to determine whether high dietary iron will negate the protective effect of unsaturated fat against hyperlipidemia. Forty- eight weanling, male Sprague Dawley rats were randomly assigned to 8 dietary groups differing in the levels of copper and iron and type of dietary fat (saturated or unsaturated). The diets were either deficient (0.6 ug Cu/g) or adequate (6.8 ug Cu/g) copper and either adequate (53 ug Fe/g) or high (506 ug Fe/g) iron. All diets contained starch as the sole source of dietary carbohydrate. Regardless of the type of dietary fat, three copper-deficient rats fed the high levels of dietary iron died prematurely due to ruptured hearts. Surviving rats belonging to the copper deficiency and high-dietary iron regimen developed severe anemia, enlarged hearts and livers, and exhibited the highest levels of liver iron. These rats also developed hypercholesterolemia. Triglycerides were elevated by the consumption of high iron diets. Data show that levels of dietary iron not the type of dietary fat are potential inducers of hypertriglyceridemia. Data also show that the combination of high iron intake and dietary copper deficiency is responsible for elevating blood cholesterol.

Last Modified: 9/20/2014