Effects of antioxidant vitamins C and E on atherosclerosis in lipid-fed rabbits

Antioxidant vitamins are hypothesized to help prevent atherosclerosis by blocking lipoprotein oxidation. We investigated the effects of dietary vitamins C and E on atherosclerosis in rabbits.

Forty New Zealand male rabbits were divided into 4 groups: 0.3% cholesterol diet with (LV) and without vitamin (LC), and 0.5% cholesterol diet with (HV) and without vitamins (HC). The treated groups consumed 137 +/- 8 mg/day vitamin C and 80 +/- 4 mg/day vitamin E for 10 weeks. Vitamin treatment did not significantly affect serum lipids. Alpha-tocopherol values were significantly higher in both serum (mg/dl) and omental fat (microg/g) among the treated rabbits (3.9 +/- 0.5 and 31.6 +/- 2.1 for LV, 1.7 +/- 0.2 and 12.1 +/- 1.9 for LC, 5.6 +/- 0.8 and 51.3 +/- 9.3 for HV and 1.9 +/- 0.3 and 8.2 +/- 0.4 for HC; p < 0.001). Vitamin treatment did not affect the percent of surface lesions in the aorta and pulmonary artery (23.8 +/- 5.2 and 20.1 +/- 3.3% for LV, 19.8 +/- 5.6 and 23.2 +/- 3.5% for LC, 28.1 +/- 6.5 and 51.1 +/- 4.2% for HV and 32.4 +/- 5.5 and 43.7 +/- 3.9% for HC, respectively; p = 0.981 and p = 0.562.

Although significantly higher values of alpha-tocopherol were found in both serum and omental fat, antioxidant vitamins C and E did not demonstrate a significant protective effect on atherosclerosis in lipid-fed rabbits during the 10-week study period.