Low fat diet and oxidative damage.

B13

Background: Obesity is increasing in the general U.S. population, especially among African American women. Obesity and fatty diet induce oxidative stress, which in turn may be associated with breast carcinogenesis. Interventions that reduce oxidative stress-induced DNA damage in susceptible women may therefore translate into successful cancer prevention strategies. We utilized a dietary intervention randomized study to test the hypothesis that a low-fat diet and weight loss can modulate levels of 8-OH-dG (measure of oxidative damage). Methods: Fifty-seven healthy premenopausal African American women were randomized to a one-year high fiber/low fat diet (HF/LF group, n=31); or regular diet (control group, n=26). Data was available on percent body fat, body mass index (BMI) and blood specimens for measuring 8-OH-dG, at study enrollment and at 6 months. Results: The mean age of participants was 39 years. The HF/LF group had a significant decrease in percent calories from fat (mean change= -5.0, p-value <0.001) but no decrease in percent body fat (mean change= -0.2, p-value 0.7) or BMI (mean change= -0.2, p-value 0.5) at 6 months. In addition, there was a significant decrease in 8-OH-dG levels at 6 months in the HF/LF group (mean change= -2.6, p-value 0.01) but not in the control group (mean change= -0.7, p-value 0.2). There was no correlation between the change in risk factors (percent body fat, waist to hip ratio, BMI) and change in levels of 8-OH-dG for the HF/LF and control group at 6 months. Conclusion: Based on these preliminary findings, a larger study population is planned to assess the effect of a low fat diet and possibly weight loss on levels of 8-OH-dG and other biomarkers of oxidative damage. Chemoprevention studies should be considered that integrate dietary interventions with other agents that modulate oxidative damage to reduce breast cancer risk.