Polyphenol Intake And Biomarkers Of Oxidative Stress In Newly Diagnosed Breast Cancer Women

Oxidative stress is an imbalance between the generation of reactive species and the antioxidant defense capacity, which contribute to the development of cancer. Dietary antioxidants, such as polyphenols from fruits and vegetables, play an important role in neutralizing reactive species, reducing oxidative stress. PURPOSE: To investigate the association between polyphenol intake and biomarkers of oxidative stress in breast cancer women. METHODS: This is a cross-sectional study. The sample was composed by 128 women newly diagnosed with breast cancer admitted for surgical treatment at a Hospital in Florianópolis, Santa Catarina (Brazil) between 2006 and 2011. Dietary intake and oxidative stress biomarkers in blood were collected before adjuvant treatment. The intake of polyphenols and their subclasses (lignans, flavonoids, phenolic acids, stilbenes, and other polyphenols) was quantified using Phenol Explorer 3.6 database and classified into “lower intake” and “higher intake”. Mann-Whitney or Student's T-test was applied to identify associations between polyphenol intake and biomarkers of oxidative stress. RESULTS: The median consumption of total polyphenols in the “lower intake” group (LI) was 240.3 (141.79,341.67) mg/day, and in the “higher intake” group (HI) was 1051.3 (700.49,1344.88) mg/day. Women showing increased consumption of total polyphenols and phenolic acids had significantly lower levels of carbonyl proteins compared to the group with reduced consumption (LI: 1.06 (0.74,1.25) vs HI: 0.74 μmol/L (0.54,1.17) p = 0.0028; LI: 1.04 (0.74,1.26) vs HI:0.74 μmol/L (0.54,1.17) p = 0.0050, respectively). There were no associations between total polyphenols intake and their subclasses, and TBARS or FOX concentrations in the present study. CONCLUSION: These findings suggest that increased intake of total polyphenols and phenolic acids may promote the reduction in concentrations of carbonyl proteins in breast cancer women.