DALLAS -- October 17, 1997 -- Synthetic vitamin E works as well as natural vitamin E in preventing heart disease, according to a clinical trial at UT Southwestern Medical Center at Dallas.
Animal tests have indicated that natural alpha tocopherol - the most active form of vitamin E - is more potent than the synthetic version of the vitamin. Natural alpha tocopherol is absorbed better in the bloodstream, leading to levels 1.5 times higher than with synthetic doses.
"We wanted to see if this held true in humans," said Dr. Ishwarlal Jialal, a senior investigator in The Center for Human Nutrition at UT Southwestern and the study's principal investigator.
A dose-response comparison of natural and synthetic vitamin E at equivalent doses in humans found no significant difference in the amount of vitamin E present in plasma or in low-density lipoproteins (LDL). Also, there was no difference in their abilities to inhibit the oxidation of LDL, the so-called "bad" cholesterol. LDL oxidation is believed to be the first step in development of atherosclerosis, or hardening of the arteries.
The findings were reported in the October issue of the American Heart Association Journal, Arteriosclerosis, Thrombosis, and Vascular Biology. The study was coordinated by Sridevi Devaraj, a research fellow in pathology.
"This is an important observation for patients on vitamin E," said Dr. Jialal. "A previous study from (the University of) Cambridge, England, showed that vitamin E at doses of 400 and 800 international units (IUs) a day reduced heart attacks by 77 percent in patients with heart disease."
Only one previous study in humans had directly compared natural and
synthetic vitamin E. A University of California, San Diego, School of Medicine
study detected no differences between a 1,600 IU dose of natural or synthetic
vitamin E in patients wit
Contact: Bridgette Rose McNeill
UT Southwestern Medical Center