Vitamin E linked to lower heart attack risk, but only if used alone?
Doses of vitamin E ranging from 400 to 800 IU per day were associated with a 20% reduction in myocardial infarction risk, report scientists from the Sapienza University of Rome and the IRCCS Istituto Neurologico Mediterraneo Neuromed in Italy.
“The fact that vitamin E, which is a known antioxidant, reduced the clinical sequelae of atherosclerotic disease may suggests the oxidative stress theory is still valid and that modulation of oxidative stress should be an important future goal to achieve to reduce atherosclerosis,” they wrote in Nutrition, Metabolism and Cardiovascular Diseases.
“It should be underlined, however, that the antioxidant effect could not be the only mechanism accounting for the anti-atherosclerotic property as vitamin E possesses other anti-inflammatory activities such as inhibition of muscle cell proliferation, monocyte-endothelial adhesion and inflammatory cytokine release, which are independent from inhibition of oxidative stress.”
Vitamin E is a family of eight separate but related molecules: four tocopherols (alpha, beta, gamma, delta) and four tocotrienols (alpha, beta, gamma, delta). While alpha-tocopherol is found in most multivitamins and is supplemented in foods, a growing base of evidence suggests that this popular vitamin E interferes with the uptake and function of tocotrienols. Tocotrienols are derived from three major sources, including rice, palm and annatto.
Commenting on the study’s findings, Dr Michael McBurney, PhD, VP Science, Communication & Advocacy – DSM Nutritional Products, told us that the study reiterates the cardiovascular benefits of vitamin E. “This meta-analysis of 16 randomized, controlled clinical trials finds that vitamin E supplementation may reduce the risk of heart attacks (myocardial infarction). With over 90% of Americans not consuming recommended daily amounts of vitamin E, this is an important observation. In their meta-analysis, the few studies not showing benefits (POPADAD, CLIPS, and MVP) were those involving people being treated for diabetes or after cardiovascular surgery. It is not surprising to find great variability in studies complicated by disease and a myriad of medications.
“This study, along with recent clinical trials reporting vitamin E supplementation helped maintain brain function in persons with mild cognitive impairment emphasizes the importance of consuming vitamin E. Clinical studies suggest that vitamin E supplementation may help maintain normal liver function in overweight and obese individual.
“Bottom line: Most of us do not consume enough vitamin E. On average, our vitamin E concentrations are lower than those measured at baseline in most of the clinical trials conducted during the 1980-2000 period. We should be concerned that suboptimal vitamin E levels in blood and tissues may be jeopardizing our health,” added Dr McBurney.
The Italian researchers pooled data from 16 randomized controlled trials to investigate if vitamin E alone or in combination with other antioxidants had an impact on heart attack risk.
Data showed that, when vitamin E was given alone, the risk of myocardial infarction was reduced by 20%, with the effect mostly driven by fatal myocardial infarction, said the researchers.
On the flip side, no effects were observed when vitamin E was combined with other antioxidants.
“Based on the positive results of this meta-analysis, we believe that the potential clinical benefit of vitamin E supplementation for primary or secondary prophylaxis of atherosclerosis should be further investigated in interventional trials,” stated Prof Loffredoand his co-workers.
“In this context, pharmaco-dynamic studies assessing the effect of vitamin E on markers of either clotting and platelet activation or oxidative stress should be done in patients at risk or with cardiovascular events to define the optimal dose which affects either.”
Source: Nutrition, Metabolism and Cardiovascular Diseases
Published online ahead of print, doi: 10.1016/j.numecd.2015.01.008
“Supplementation with vitamin e alone is associated with reduced myocardial infarction: a meta-analysis”
Authors: L. Loffredo, L. Perri, A. Di Castelnuovo, L. Iacoviello, G. De Gaetano, F. Violi