The Effects of a Flavonoid-Rich Diet on Oxidative Stress, Inflammation, and Lipid Profile after Elective Percutaneous Coronary Intervention: A Randomized Clinical Trial

Antioxidant-rich foods may decrease oxidative stress and have a direct impact on atherosclerosis by reducing low-density lipoprotein (LDL) oxidation. Our aim was to assess the impact of a flavonoid-rich diet on oxidative stress, inflammatory response, and lipid profile in patients with coronary artery disease submitted to elective percutaneous coronary intervention (PCI). Thirty-three patients submitted to elective PCI were randomly allocated to follow either a flavonoid rich antioxidant (AOX) diet or a control diet based on National Cholesterol Education Program Adult Treatment Panel III recommendations. Patients were followed for 6 months. Dietary intake was recorded at the start and at the end of the follow-up period, as were oxidative stress markers (ferric reducing ability of plasma and protein sulphydryl) and C-reactive protein (CRP). Patients randomized to follow the AOX diet had a reduction in energy, carbohydrate, and lipid intake, as well as increased flavonoid intake. Compared to the control group, there were no changes in oxidative stress markers or CRP in the patients following the AOX diet, but these patients had a significant decrease in LDL cholesterol levels. In conclusion, the findings of this study suggest that a flavonoid-based antioxidant-rich diet is not associated with reductions in oxidative stress or inflammatory markers 6 months after percutaneous coronary intervention. Nonetheless, patients in the intervention group experienced significant reductions in LDL cholesterol, which may indicate cardiovascular benefits of AOX diets despite of inflammation and oxidative stress markers.