Diet and oxidative stress in breast, colon and prostate cancer patients: a case-control study.

To study the changes in pro-oxidant-antioxidant status in breast, colon and prostate cancer patients as compared to respective controls. Cross-sectional case-control study. The pro-oxidant status was measured by analysing alkanes (ethane and pentane) in exhaled air and lipid peroxidation (as malonaldehyde) in blood samples. The antioxidant capacity was measured by studying blood glutathione concentration, vitamin concentrations and serum antioxidant capacity in liposomes in vitro. Aberdeen hospitals. Breast, prostate and colon cancer cases, and age- and sex-matched control patients (hospitalized for a benign disease). Breast cancer patients were females, prostate cancer patients were males and colon cancer patients were both males and females. Controls were age-matched to within 5 years, sex-matched and matched for smoking habits. The dietary study suggested a higher monoene and polyene fat intake in prostate cancer than in controls while in other cancer patients no significant differences were found. Breast and colon cancer patients tended to have lower vitamin intakes than controls. Pentane concentration in exhaled air increased in breast cancer patients as compared to respective controls. In serum total antioxidant capacity no significant differences were found. Both breast and colon cancer patients showed decreased C18:2 and C20:4 fatty acid concentrations in red blood cells while C22:6 concentration was elevated in breast cancer patients. Oxidative stress may be associated with malignant diseases, suggesting the importance of simultaneous analysis of pro- and antioxidation in the search of mechanistic parameters leading to the tumour formation.