Paraoxonase 1 Q192R (PON1-192) polymorphism is associated with reduced lipid peroxidation in R-allele-carrier but not in QQ homozygous elderly subjects on a tomato-rich diet

Background The oxidative modification of LDL is considered to play a central role in the pathogenesis of atherosclerosis and coronary heart disease (CHD). Paraoxonase (PON1) protects LDL from oxidation and may therefore retard the development of athero. The PON1-192 polymorphism is associated with diminished PON 1 concentrations and an increased risk for CHD in RR-allele subjects. Aim of the study To investigate the effect of tomato juice consumption on PON I activity and other parameters related to oxidative stress in healthy elderly subjects. Furthermore, the PON1-192 genotype has been determined in the volunteers in order to see whether possible treatment effects are related to the PON1-192 polymorphism. Methods Fifty elderly subjects were randomly assigned to control (mineral water) or intervention group (tomato juice). Subjects of the tomato juice group consumed daily 330 mL tomato juice for 8 weeks. Antioxidant status was measured as LDL oxidation, plasma malondialdehyde, ferric reducing ability of plasma (FRAP) and PON1 activity. The PON1-192 polymorphism was determined by restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR). Plasma carotenoids were analyzed by HPLC. Results Tomato juice consumption reduced LDL-oxidation and improved antioxidant status in R-allele carriers, but not in the QQ genotype group. PON1 activity increased irrespective of the genotype in both, control and intervention group. Conclusions The changes in antioxidant status after tomato juice consumption seem to depend on the PON1-192 genotype. Healthy elderly, carrying the R-allele, could specificly reduce their higher cardiovascular risk by changing dietary habits.