RANDOMIZED, CONTROLLED TRIAL OF ANTIOXIDANT VITAMINS AND CARDIOPROTECTIVE DIET ON HYPERLIPIDEMIA, OXIDATIVE STRESS, AND DEVELOPMENT OF EXPERIMENTAL ATHEROSCLEROSIS - THE DIET AND ANTIOXIDANT TRIAL ON ATHEROSCLEROSIS (DATA)

The effects of administration of guava and papaya fruit (100 g/day), v egetables, and mustard oil (5 g/day) (group A); antioxidant vitamins C (50 mg/day) and E (30 mg/day) plus betacarotene (10 mg/day) (group B) ; a high-fat (5-10 g/day) (group C); or a Low-fat (4-5 g/day) diet (gr oup D) were compared over 24 diet weeks in a randomized fashion, while all groups of rabbits (five in each of four groups) received a hydrog enated fat diet (5-10 g/day) for a period of 36 weeks. After 12 weeks on the high-fat diet, each group of rabbits had an increase in blood l ipoproteins. The fruit and vegetable-enriched prudent diet (group A) c aused a significant decline in blood lipids at 24 and 36 weeks, wherea s the lipid levels increased significantly in groups C and D. Group A also had a significant rise in vitamin E (2.1 Umol/l), C (10.5 Umol/l) , A (0.66 Umol/l), and carotene (0.08 Umol/l) and a decrease in lipid peroxides (0.34 nmol/ml at 36 weeks, whereas the levels were unchanged in groups C and D. Group B rabbits had a significant and greater incr ease than group A in plasma vitamins E, C, A, and carotene; a rise in HDL cholesterol; and a greater decrease in lipid peroxides after 24 an d 36 weeks of treatment. After stimulation of lipid peroxidation in al l rabbits, 3 of 5 group C and 2 of 5 group D rabbits died due to coron ary thrombosis, whereas in groups A and B there were no deaths, indica ting that antioxidant therapy can provide protection against lipid per oxidation and free radical generation. Aortic lipids and sudanophilia, indicating atherosclerosis, were significantly higher in groups C and D than in groups A and B. Fatty streaks and atheromatous and fibrous plaques were noted in all the rabbits in groups C and D. Intimal fibro sis and medial degeneration were also present in the group C rabbits. While group A (36.4 +/- 4.4 mu m) and group B (37.1 +/- 4.2 rho m) rab bits had minimal coronary artery plaque sizes, group C (75.4 +/- 10.6 mu m) and group D rabbits (69.5 +/- 6.2 mu m) had significantly greate r plaque sizes. Aortic plaque sizes were also greater in groups C and D than in groups A and B. It is possible that combined therapy with an tioxidant vitamins C, E, and carotene, and a diet rich in antioxidants , could independently inhibit free radical generation and the developm ent of atherosclerosis.