Vitamin E Can Cut Heart Disease Risk in Diabetics

"Vitamin E might therefore be effective in preventing early endothelial damage in type 2 diabetes mellitus, possibly representing a new tool for endothelial protection," wrote lead author Arianna Vignini from Polytechnic University of Marche in Ancona.

Type 2 diabetics are known to be at increased risk of cardiovascular disease, and this has been linked to a decrease in fibrinolysis - a process whereby the protein fibrin is broken down in the bloodstream. Fibrin plays an active role in coagulation of the blood.

The decrease is fibrinolysis has been linked to increased production of plasminogen activator inhibitor type 1 (PAI-1), as is observed in diabetics, as well as cellular adhesion molecules, including the vascular cell adhesion molecule-1 (VCAM-1) and the intracellular adhesion molecule (ICAM).

The researchers assigned the 24 men and 13 women to receive the daily vitamin E supplements for 10 weeks, and then followed them for a further 20 weeks. At the end of the study, Vignini and co-workers report that PAI-1 levels decreased by 32 per cent after ten weeks, and returned to approximate baseline levels after a further 20 weeks without supplementation.

Moreover, VCAM-1 and ICAM levels decreased after 10 weeks, by 12 and 19 per cent, respectively.

In addition, the production of nitric oxide (NO) - a molecule key for better blood flow - increased by about 50 per cent after ten weeks of vitamin E supplementation.

Nitric oxide (NO) is a molecule used by the endothelium (cells lining the surface of blood vessels) to signal surrounding muscle to relax, leading to a reduction in blood pressure, reduced blood clotting and protection against myocardial infarction and strokes.

Despite the positive results and implications for type-2 diabetics, the authors sounded a note of caution, stating that no control arm with a placebo was used, and the study was not double-blind and randomized.

"Because of these limitations, our results can be considered highly suggestive of an effect of vitamin E supplementation on endothelial function in T2DM, but also indicates the need for further placebo-controlled studies on this issue," they stated.

In terms of vitamin E supplements and heart health for the wider population, a recent study reported that a higher dose - 3200 International Units - of vitamin E is needed to reduce oxidative stress in individuals at risk for cardiovascular disease, and this may be why previous trials using lower doses failed to show any benefits for the vitamin (Free Radical Biology and Medicine, doi 10.1016/j.freerradbiomed, 2007.06.019

There are eight forms of vitamin E: four tocopherols (alpha, beta, gamma, delta) and four tocotrienols (alpha, beta, gamma, delta). Alpha-tocopherol (alpha-Toc) is the main source found in supplements and in the European diet, while gamma-tocopherol (gamma-Toc) is the most common form in the American diet.

Source: Diabetes In Control: Source: Nutrition, Metabolism and Cardiovascular Diseases (Elsevier) "A study on the action of vitamin E supplementation on plasminogen activator inhibitor type 1 and platelet nitric oxide production in type 2 diabetic patients" Authors: A. Vignini, L. Nanetti, C. Moroni, R. Testa, C. Sirolla, M. Marra, S. Manfrini, D. Fumelli, F. Marcheselli, L. Mazzanti and R.A. Rabin