A High fiber, Low Fat Diet Leads to Upregulation of Endogenous Antioxidants in African-American Women from the ANULIFE Study

Studies indicate correlations between reactive oxygen species (ROS)-induced oxidative DNA damage and the incidence of breast cancer. Although normal levels of ROS are essential for cellular signaling, increased levels of ROS can cause lipid, protein and DNA damage which can be neutralized by endogenous antioxidants such as catalase (CAT) and superoxide dismutase (SOD). However, the impact of healthier dietary changes on the endogenous antioxidant system and the role in reducing oxidative stress has not been widely investigated.  In a randomized design, 200 African-American women participating in the ANULIFE study were assigned to either a control group (basic nutritional information) or intervention group (required to follow a low fat, high fiber diet). Blood samples were collected at 0, 6, 12 months and serum levels of catalase and SOD were determined using highly sensitive enzymatic assays. The dietary intervention significantly increased serum catalase levels compared to the control group after 12 months (P<0.05).  Similarly, a significant  increase in SOD was observed in the intervention group after 6 and 12 months (P<0.05)  Those participants in the intervention group between the ages of 30-40 yrs old and with body mass index greater than 30 demonstrate the most significant increases (P<0.05). These results show evidence that a low fat, high fiber diet can influence increases in the endogenous antioxidant system after only 6 months and suggest further studies are necessary to investigate mechanism.