Effects of tomato juice consumption on plasma and lipoprotein carotenoid concentrations and the susceptibility of low density lipoprotein to oxidative modification

Effects of tomato juice supplementation on the carotenoid concentration in lipoprotein fractions and the oxidative susceptibility of LDL were investig ated in 31 healthy Japanese female students. These subjects were randomized to one of three treatment groups; Control, Low and High. The Control, Low and High groups consumed 480 g of a control drink, 160 g of tomato juice pl us 320 g of the control drink, and 480 g of tomato juice, providing 0, 15 a nd 45 mg of lycopene, respectively, for one menstrual cycle. The ingestion of tomato juice, rich in lycopene but having little beta -carotene, increas ed both lycopene and beta -carotene. Sixty-nine percent of lycopene in plas ma was distributed in the LDL fraction and 24%, in the HDL fraction. In the Low group, the lycopene concentration increased 160%, each in the VLDL+IDL , LDL and HDL fractions (P<0.01). In the High group, the lycopene concentra tion increased 270% each in the VLDL+IDL and LDL fractions, and 330%, in th e HDL fraction (p<0.01). beta -Carotene also increased 120% and 180% in LDL fractions of the Low and the High groups, respectively. Despite these caro tenoid increases in LDL, the lag time before oxidation was not prolonged as compared with that of the Control group. The propagation rate decreased si gnificantly after consumption in the High group. Multiple regression analys is showed a positive correlation between lag time changes and changes in th e alpha -tocopherol concentration per triglyceride in LDL and a negative co rrelation between propagation rate changes and changes in the lycopene conc entration per phospholipid in LDL. These data suggest that alpha -tocophero l is a major determinant in protecting LDL from oxidation, while lycopene f rom tomato juice supplementaion may contribute to protect phospholipid in L DL from oxidation. Thus, oral intake of lycopene might be beneficial for am eliorating atherosclerosis.