Lycopene, lutein and beta-carotene as determinants of LDL conjugated dienes in serum.

Oxidative modification of low-density lipoprotein (LDL) in the vascular endothelium is considered to be important in the development of early atherosclerosis. The aim of this study was to investigate the main determinants of serum LDL conjugated dienes in women (n=124) and men (n=225). We focused on the influence of fat-soluble vitamins and carotenoids on the concentration of conjugated dienes in LDL. In multivariate linear regression models, including age, body mass index, diastolic blood pressure, symptomatic ischaemic heart disease (IHD) or IHD history, statin medication, leukocytes and serum triglycerides as covariates, plasma lycopene (standardized beta=-0.33; P=0.002) and lutein (standardized beta=-0.22; P=0.027) concentrations were the strongest determinants of serum LDL conjugated dienes in women, whereas plasma beta-carotene (standardized beta=-0.23; P=0.002) was the most important factor in men. Furthermore, statin medication, diastolic blood pressure, age and serum triglycerides were significant determinants of LDL conjugated dienes. The regression model with lycopene contributed to 29% in women and 15% in men with beta-carotene of the variation of serum LDL conjugated dienes. Results of the present study suggest that plasma lycopene, lutein and beta-carotene are the most powerful antioxidants for explaining the content of in vivo oxidatively modified LDL in serum.