TPS 771: Diet and lifestyle, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Introduction: Persistent organic pollutants (POPs), including organochlorine pesticides (OCP), PCBs and PBDEs, are mostly fat-soluble chemicals with long half-lives and associated with adverse health outcomes. Because POPs accumulate in humans with age, there is need to identify ways to enhance their excretion from human tissues. We hypothesized that consumption of nuts that have incomplete intestinal absorption or the fat-substitute olestra can enhance the excretion of POPs in 50-70-year-old adults within a randomized controlled trial. Methods: We randomized 47 men and women to 3 treatment arms: A) whole or diced almonds and walnuts (110g/day), B) olestra from fat free potato chips (18g of olestra/day), or C) vegetable oil from standard potato chips (17.4g of oil/day, control group). We assessed change from baseline of the concentrations of 9 POPs that were detectable in >75% of participants in plasma after 6 months of treatment. Models adjusted for age, gender, cholesterol and triglyceride concentrations at baseline and follow-up. Results: All treatment groups resulted in lower values for all 3 classes of POPs after the 6-month trial. The relative differences of POPs 6-month changes of participants receiving nuts or olestra (vs controls) were: ∑PBDEs: -56.7% (-95.0%, -18.5%) and -29.9% (-66.4%, 6.6%), respectively; ∑PCBs: -7.5% (-23.6%, 8.6%) and 2.9% (-12.4%, 18.2%), respectively; ∑OCPs: 27.4% (-17.6%, 72.4%) and -29.6% (-72.6%, 13.3%). Discussion: Supplementation with nuts or olestra were associated with substantial decreases in POPs levels. Olestra resulted in substantial reductions in PBDE and OCP concentrations whereas nut treatment resulted in reductions in PBDE and PCB concentrations but was not as effective in reducing OCP concentrations as the control group. This trial shows promising results of 2 dietary interventions to enhance the excretion of some POPs.