Copper supplementation has no effect on markers of DNA damage and liver function in healthy adults (FOODCUE project).
OBJECTIVE
Copper is routinely used in the laboratory to promote oxidation in vitro. However, copper concentrations are million-fold higher than physiological concentrations and, in contrast, accumulating evidence suggests that copper may have an antioxidant role in vivo. The aim of this study was to provide data on how increased intake of copper affected mononuclear leukocyte DNA damage and liver function in healthy young free-living men and women.


METHODS
The study design was a double-blind repeated crossover trial with treatment and intervening placebo periods, each of 6 weeks' duration. The following supplementations were given orally in sequence: CuSO(4) at a dose of 3 mg copper/day and copper amino acid chelates at doses of 3 and 6 mg copper/day. Oxidative DNA damage was assessed using a modification of the alkaline Comet assay incorporating an endonuclease III digestion step. The assessment of liver function was by measurement of the liver enzymes, alanine aminotransferase and L-gamma-glutamyltransferase.


RESULTS
There was no significant alteration in mononuclear leukocyte DNA damage or on liver function after 6 weeks of copper supplementation at two doses (3 and 6 mg/day).


CONCLUSIONS
Copper supplementation (giving total copper intake at the highest level of 7 mg/day) did not induce DNA damage or adversely affect liver function in healthy adults.
O'Connor
J M
JM
Northern Ireland Centre for Food and Health (NICHE), Department of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland. jm.oconnor@ulster.ac.uk
Bonham
M P
MP
Turley
E
E
McKeown
A
A
McKelvey-Martin
V J
VJ
Gilmore
W S
WS
Strain
J J
JJ
D000328:Adult; D000410:Alanine Transaminase / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D002469:Cell Separation; D004396:Coloring Agents; D020552:Comet Assay; D003300:Copper; D004249:DNA Damage / Q000187:drug effects*; D004032:Diet; D019587:Dietary Supplements; D004591:Electrophoresis, Polyacrylamide Gel; D004720:Endonucleases / Q000737:chemistry; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000378:metabolism / Q000648:ultrastructure; D008099:Liver / Q000187:drug effects / Q000502:physiology*; D008111:Liver Function Tests; D008856:Microscopy, Fluorescence
D004396:Coloring Agents; D003300:Copper; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D004720:Endonucleases