RESUMO
Antioxidants appear to play a role in the prevention of atherosclerosis. Here, we investigated the antioxidant properties of a γ-tocotrienol and α-tocopherol enriched fraction of palm oil, in patients with carotid atherosclerosis. Serum lipids, fatty acid peroxides, platelet aggregation, and carotid artery stenosis were measured over a 24-month period in 50 patients with cerebrovascular disease. Change in stenosis was measured with bilateral duplex ultrasonography. These studies revealed apparent carotid atherosclerotic regression in eight and progression in two of the 25 antioxidant patients, while none of the control group exhibited regression and ten of 25 showed progression (p<0.01). Serum α-tocopherol doubled while tocotrienols were undetectable throughout the study. Serum thiobarbituric acid reactive substances, decreased in the treatment group from 1.08 ± 0.14 to 0.80 ± 0.14 µM (p<0.05) after 24 months, and in the placebo group, they increased nonsignificantly from 0.99 ± 0.16 to 1.06 ± 0.17 µM. Both antioxidant and placebo groups displayed significantly increased collagen-induced platelet aggregation responses (p<0.05) as compared with entry values. Serum total cholesterol, low density lipoprotein cholesterol, and triglyceride values remained unchanged in both groups, as did the plasma high density lipoprotein cholesterol values. Palm oil tocols appear to benefit the course of carotid atherosclerosis.