By Sean Henahan, Access Excellence

DALLAS, TX (5/1/96)- High doses of vitamin E appear to reduce the risk for cardiovascular disease in patients with diabetes, report researchers at the University of Texas Center for Human Nutrition.

"This is exciting because it may be a new way to prevent heart disease in diabetics. It's the first study to include men and women with both type I and type II diabetes who have a wide range of glucose control. This study goes a couple of steps further than any previous work," said Dr. Ishwarlal Jialal, an associate professor of pathology and internal medicine and senior author of the paper detailing the research.

Numerous studies have shown that vitamin E, an antioxidant, can reduce susceptibility to heart disease in nondiabetic patients by inhibiting the oxidation of low-density lipoprotein (LDL), the "bad" cholesterol. This oxidative process is believed to lead to atherosclerosis, a condition in which arteries become clogged with fatty deposits. Last year, Jialal reported that a minimum dose of 400 International Units of vitamin E per day produced a protective effect.

Few studies have dealt with diabetic patients even though they are more prone to premature atherosclerosis, the leading cause of heart attacks and strokes. It is not clear why diabetics are at increased risk, but researchers know they have a lower concentration of antioxidants and a tendency to oxidize more "bad" cholesterol. Diabetics also experience greater protein glycation than nondiabetics. Protein glycation is the result of glucose binding to proteins. If glucose binds to LDL, it increases the buildup of atherosclerotic plaque. Diabetics typically have high glucose levels.

Jialal and his team wanted to see if vitamin E could reduce LDL oxidation and decrease protein glycation in diabetics. Twenty-eight men and women with insulin-dependent diabetes mellitus (type I) and non-insulin-dependent diabetes mellitus (type II) in varying stages of glycemic control were assigned randomly to receive either a placebo or 1,200 IU of vitamin E for eight weeks. The Recommended Dietary Allowance for vitamin E is 10 milligrams. (One IU of vitamin E is roughly equivalent to 1 mg of vitamin E.)

Compared with the placebo group, the supplemented group had significant reductions in LDL oxidation. There was no effect on the level of protein glycation. "The benefit to LDL oxidation was seen in both type I and type II diabetes," Jialal said.

The study results appeared in the May 1996 issue of The American Journal of Clinical Nutrition.

Related information on the Internet

American Diabetes Association

CDC Diabetes Page

Newsmaker Nutrition Interview

AE/UCSD Online Nutrition Course