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Copper Intake (copper + intake)

Distribution by Scientific Domains

Medical Sciences	60%

Selected Abstracts

Dietary zinc, copper and selenium, and risk of lung cancer

INTERNATIONAL JOURNAL OF CANCER, Issue 5 2007
Somdat Mahabir
Abstract Zinc, copper and selenium are important cofactors for several enzymes that play a role in maintaining DNA integrity. However, limited epidemiologic research on these dietary trace metals and lung cancer risk is available. In an ongoing study of 1,676 incident lung cancer cases and 1,676 matched healthy controls, we studied the associations between dietary zinc, copper and selenium and lung cancer risk. Using multiple logistic regression analysis, the odds ratios (OR) and 95% confidence intervals (CI) of lung cancer for all subjects by increasing quartiles of dietary zinc intake were 1.0, 0.80 (0.65,0.99), 0.64 (0.51,0.81), 0.57 (0.42,0.75), respectively (p trend = 0.0004); similar results were found for men. For dietary copper, the ORs and 95% CI for all subjects were 1.0, 0.59 (0.49,0.73), 0.51 (0.41,0.64), 0.34 (0.26,0.45), respectively (p trend < 0.0001); similar reductions in risk and trend were observed by gender. Dietary selenium intake was not associated with risk, except for a significant inverse trend (p = 0.04) in men. Protective trends (p < 0.05) against lung cancer with increased dietary zinc intake were also found for all ages, BMI > 25, current smokers, pack-years ,30, light drinkers and participants without emphysema. Increased dietary copper intake was associated with protective trends (p < 0.05) across all ages, BMI, smoking and vitamin/mineral supplement categories, pack-years ,30 and 30.1,51.75 and participants without emphysema. Our results suggest that dietary zinc and copper intakes are associated with reduced risk of lung cancer. Given the known limitations of case,control studies, these findings must be interpreted with caution and warrant further investigation. © 2006 Wiley-Liss, Inc. [source]

The lowering effect of high copper intake on selenium retention in weanling rats depends on the selenium concentration of the diet

JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 1-2 2001
S. Yu
The question addressed was whether the influence of dietary copper concentration on selenium metabolism depends on the amount of selenium in the diet. Weanling, male rats were fed purified diets containing either 1 (low), 4 (normal) or 42 (high) mg Cu/kg diet and either 0.03 (low), 0.05 (normal) or 1.0 (high) mg Se/kg diet in a 32 factorial design. Extra copper was added to the diets in the form of CuSO4,·,5H2O and selenium as Na2SeO3,·,5H2O. In rats fed either the low or normal amounts of selenium, higher intakes of copper decreased the apparent intestinal selenium absorption and increased urinary selenium excretion. The effects of copper on selenium absorption, excretion and retention were not seen in rats fed the high-selenium diets. An increase in dietary copper concentrations elevated selenium concentrations in the liver and kidneys, but slightly lowered those in the spleen of rats that were fed the diets with the normal level of selenium. In rats that were fed the diets with either low or high selenium concentration, copper intake had no effect on organ selenium concentrations. Glutathione peroxidase activity in erythrocytes was raised by feeding the diets which contained either normal or high copper content instead of those that were low in copper. It is concluded that the amount of selenium in the diet determines whether or not an increase in dietary copper concentration affects selenium metabolism. [source]

Mild zinc deficiency and dietary phytic acid accelerates the development of fulminant hepatitis in LEC rats

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 2 2007
Akiko Saito
Abstract Background and Aim:, Restriction of copper intake delays hepatic copper accumulation in Long,Evans Cinnamon (LEC) rats, which are animal models of Wilson's disease. Involvement of zinc is suggested to develop hepatitis in the disease; however, this has not been clarified. The aims of this study were to investigate the effects of mild zinc deficiency on the development of hepatitis and to determine the relationship between the absorption and hepatic levels of copper, zinc and iron. Methods:, Male LEC and F344 (wild type atp7b) rats were fed a low zinc, phytate-containing or control diet. The onset of hepatitis (Experiment 1), and absorptive rates of copper, zinc and iron and hepatitis indices in 4 weeks (Experiment 2) were observed. Results:, The onset of fulminant hepatitis in LEC rats was much earlier in the low zinc and phytate groups (mean 94.6 ± 2.74 days and 82.8 ± 3.56 days old, respectively) than in the control group (136 ± 2.11 days old) with worse hepatitis indices. Hepatic copper levels were much higher in LEC rats than F344 rats, but were not largely different among the diet groups without prominent changes in copper absorption. Hepatic levels and intestinal absorption of zinc and iron were lower in the phytate group than in the control group. Conclusion:, Mild zinc deficiencies caused by a low zinc or phytate-containing diet accelerate the onset of hepatitis in LEC rats without increasing copper absorption, and zinc and iron metabolism may be involved in the earlier onset of jaundice of LEC rats. [source]