Dietary Antioxidant Capacity Indices are Negatively Correlated to LDL-Oxidation in Adults

Former research studies have demonstrated controversial associations between dietary indices and oxidative stress biomarkers including oxidized low-density lipoprotein (ox-LDL) and malondialdehyde (MDA). So, in this cross-sectional study, we aimed to assess the association of dietary total antioxidant capacity (DTAC), oxidative balance score, and phytochemical index (PI) with ox-LDL/MDA in a healthy adult population of Shiraz, Iran.

236 individuals participated in this cross-sectional study. DTAC, OBS, and PI were calculated using a 168-item food frequency questionnaire (FFQ), which was previously validated in Iran. We measured ox-LDL and MDA in blood samples of the participants using commercially existing kits. Crude and adjusted models of linear regression were used to evaluate the relation of dietary indices with ox-LDL and MDA.

There was a significant association between ox-LDL and DTAC in both crude (β = -1.55; 95% CI: -2.53, -0.58; P-trend = 0.002) and adjusted (β = -1.65 95% CI: -2.66, -0.64; P-trend = 0.001) models. Also, a negative association was observed between ox-LDL and PI in the crude (β = -1.26 95% CI: -2.33, -0.29; P-trend = 0.01) and adjusted (β = -1.36 95% CI: -2.38, -0.34; P-trend = 0.01) models.

Results of this study showed that DTAC and PI were inversely associated with ox-LDL as markers of lipid peroxidation. But no correlations were seen between MDA and dietary antioxidant indices.