Vitamin E's possible heart benefits are described in a letter published in the November issue of the journal Diabetes Care. The letter was written by researchers, including Andrew Levy, MD, PhD, of Technion-Israel Institute of Technology in Haifa, Israel.
Levy and colleagues reviewed data from the Heart Outcomes Prevention Evaluation trial, which was conducted in 2000. That study included more than 3,000 participants, about a third of whom had diabetes.
The HOPE trial tested the benefits of taking 400 international units of vitamin E daily for 4.5 years. It found that vitamin E supplements had no significant benefit against heart attack, stroke, and death from cardiovascular disease, regardless of diabetes status.
However, the trial might have missed a key piece of information.
Participants with a particular form of a blood protein called haptoglobin who took vitamin E cut their risk of dying from cardiovascular disease by 55% and decreased their risk of nonfatal heart attack by 43%, say Levy and colleagues.
Haptoglobin comes in three forms: "2-2," "1-1," and "2-1." Haptoglobin's 2-2 form is the worst of the three at fighting disease-causing free radicals. People with diabetes who have haptoglobin's 2-2 form of the protein have a higher risk of cardiovascular "events," such as heart attacks, write the researchers.
About 40% of people with diabetes have the 2-2 form of haptoglobin, according to a news release.
Levy's team noted the possible vitamin E-haptoglobin connection after examining the original trial for haptoglobin subtype. However, vitamin E didn't show the same protective trend against stroke.
A larger five-year study of people with diabetes with haptoglobin 2-2 subtype is underway in Israel, according to a news release.
"If this larger study confirms our findings, the public health implications would be huge," says Levy in the release.
Levy is the author of a patent that claims to predict diabetic vascular disease based on type of haptoglobin.