Submitted to: Trace Elements in Man and Animals International Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 6/2/2002
Publication Date: 5/1/2003
Citation: Davis, C.D. Effect of dietary copper (Cu) on risk factors for colon cancer in healthy men. 2003. Journal of Nutrition. v.133(5S-1). p.259E.
Technical Abstract: Colon cancer is the second leading cause of cancer mortality in the United States. One possible dietary factor that may increase susceptibility to colon cancer is inadequate dietary Cu. Seventeen healthy, nonsmoking men aged 21-52 yr completed a controlled feeding study to investigate the effects of low and adequate Cu intakes on putative risk factors for colon cancer. The basal diet contained 0.45 mg Cu/2500 kcal. After a 1 wk equilibration period in which the subjects were fed the basal diet supplemented with 1.0 mg Cu, subjects were randomly assigned to receive either the basal diet or the basal diet supplemented with 2 mg Cu/d for 6 wk. Because the fecal water data did not follow a normal distribution, data were transformed by using the natural log before statistical analysis. Repeated measures ANOVA revealed a significantly (p<0.001) higher free radical production [1.73 (1.56-1.91) vs 1.27 (1.13-1.42) umol MSA/kg wet feces; (geometric means +/- 1 SEM)] and significantly (p<0.0001) lower fecal water Cu concentrations [0.13 (0.11-0.15) vs 0.50 (0.45-0.55) ug/mL fecal water] when subjects were fed low dietary Cu than when they were fed adequate dietary Cu. There was a significant negative correlation between fecal free radical production and fecal water Cu concentrations (r2= -0.28, p<0.05). Dietary Cu did not significantly affect fecal water pH, iron or zinc concentrations. Subjects had significantly (p<0.007) higher intestinal alkaline phosphatase activity when they were fed low dietary Cu than when they were fed adequate dietary Cu (median values of 1.34 vs 0.52 units/mL, respectively). These results suggest that low dietary Cu adversely affects fecal free radical production and fecal water alkaline phosphatase activity which are putative risk factors for colon cancer.