Relationship between vitamin E and polyunsaturated fatty acids in breast cancer. Nutritional and metabolic aspects.

Intake of vitamin E, total lipids, total cholesterol, and fatty acids were analyzed with the blood levels of vitamin E, total cholesterol, triglycerides, and the serum distribution of fatty acids in a hospital-based population of 120 patients and 109 controls. In regard to nutritional intake, the only significant differences involve saturated and monounsaturated fatty acid consumption, which is more elevated in postmenopausal patients than in postmenopausal controls. Vitamin E and total cholesterol blood levels are significantly higher in patients than in controls, where the difference is that vitamin E is independent from cholesterol level in premenopausal women only. Fatty acid serum distribution is comparable in both samples, with the exception of arachidonic acid, which is significantly lower in premenopausal patients than in premenopausal controls. Two multivariate regression analyses of the plasma vitamin E levels of patients and controls were done with menopausal status and nutrients as independent variables for the first analysis, and with menopausal status and all blood analytes for the second one. The regression coefficients for total cholesterol and triglycerides are statistically significant for both samples, whereas a positive association between vitamin E plasma level and sunflower oil consumption and between vitamin E plasma level and serum linoleic acid distribution is significant for patients only. Furthermore, the multiple regression shows that, when adjusted for analyte variables, plasma vitamin E levels are higher in premenopausal than in postmenopausal patients. In addition, plasma lipid peroxidation, evaluated by malondialdehyde measurement, is shown to be significantly lower in patients than in controls. Malondialdehyde level is associated with a significant lower odds ratio (OR) after multivariate tertile analysis (OR for the highest tertile: 0.51; 95% CI: 0.29-0.89). Together, these findings are consistent with a picture of lower lipid peroxidation in patients than in controls.