ABSTRACT
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 atherosclerosis. The PON1-192 polymorphism is associated with diminished PON1 concentrations and an increased risk for CHD in RR-allele subjects. AIM OF THE STUDY: To investigate the effect of tomato juice consumption on PON1 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 specifically reduce their higher cardiovascular risk by changing dietary habits.
