August 2005 - Cardiovascular disease (CVD) is a complex disease with multiple causes. During the past decade, the health benefits of vitamin E in prevention of atherosclerosis have been studied extensively.
In a study published in Atherosclerosis (2005, 180(1): 19-25), researchers at the Kyoto Prefectural University of Medicine, Japan, discovered that tocotrienols were a more effective form of vitamin E in reducing endothelial expression of adhesion molecules in the blood vasculature, relative to the effects of α-tocopherol.
The migration of circulating monocytes into the subendothelial space is one of the earliest events in atherosclerosis. This process is in part regulated by the expression of adhesion molecules on such as vascular cell adhesion molecule-1 (VCAM-1).
Enhanced endothelial expression of these molecules by oxidized LDL-Cholesterol has been shown to be a critical step in plaque formation and the development of atherosclerosis. Patients with atherosclerosis have been found to have high circulating levels of these soluble adhesion molecules. Attempts to lower the production of these adhesion molecules have received wide attention as a mean of reducing the risk of developing CVD.
In this study, it was found that tocotrienols inhibited both surface protein and mRNA expression of VCAM-1 on human aortic endothelial cells induced by 25-hydroxycholesterol (a component of oxidized LDL-Cholesterol). The inhibitory effect was significantly more profound with tocotrienols compared to alpha-tocopherol (the regular vitamin E).
The study further shows that tocotrienols are accumulated at levels approximately 25–95-fold greater than that of alpha-tocopherol in the human aortic endothelial cells, indicating the superior inhibitory activity of tocotrienols is largely due to the higher intracellular concentrations.
“This study with its promising results, supports the theory that tocotrienols may potentially be an important natural phytonutrient in reducing the risk of atherosclerosis,” says WH Leong, Vice President of Carotech Inc, the largest producer of palm tocotrienol complex in the world.