The Discrepancy between Vitamin E Study Results - by Nancy Hirsch, CN

An article in the March 24, 2009 issue of The New York Times cast doubt on the value of vitamin E as a preventive therapy for various diseases, including cancer, heart disease and stroke. It stated that in November of 2004, the American Heart Association warned that vitamin E did not reduce the incidence of cardiovascular disease or cancer. In fact, it went so far as to state that taking 400 International Units a day could increase the risk of death.

The studies used in the report compared the effects of supplemental vitamin E (400 units per day) with the effects of placebo.

These results seem to contradict previous research on vitamin E, which found that vitamin E is known to protect low-density lipoprotein cholesterol (LDL) from damage by oxygen – an effect that might lead to a reduction in heart disease.

There are many studies in the literature to back this up. One such study in The New England Journal of Medicine showed that (40,000) men and (87,000) women taking more than 100 IU of vitamin E per day for several years experienced a significant decrease in cardiovascular disease. This study was followed by a report from the Cambridge Heart Antioxidant Study (CHAOS) in England; “a double-blind trial confirming a dramatic reduction in non-fatal heart attacks in a group of people with coronary heart disease.” This study looked at 121,000 female nurses between the ages of 30 and 55. Approximately a quarter of these women received 400 IU of vitamin E per day, a quarter received 800 IU per day, and the remainder received placebo. The rate of non-fatal heart attacks in the vitamin E groups was more than 75% lower than in the placebo group.

Another report at the 2001 American Heart Association’s 41st annual conference in San Antonio, Texas found that taking high doses of vitamin E may help prevent heart attacks and strokes by preventing the progression of hardening of the arteries. The benefit was limited to vitamin E from supplements; no effect from dietary vitamin E was found.

The Journal of the American College of Cardiology (July 2000) noted that patients with Type 1 diabetes who took 1,000 IU of vitamin E daily had improved blood flow. And The Journal of the National Cancer Institute in 1998 stated that the incidence of prostate cancer was 32% lower among men who took vitamin E.

Another study published in Life Extension Magazine stated that vitamin E reduces high levels of the inflammation-causing C-reactive protein (CRP) and IL-6, which are likely contributors to heart disease.

The Heart Outcomes Prevention Trials (HOPE and HOPE-TOO) mentioned in The New York Times article were funded mainly by the pharmaceutical company, Aventis. Closer examination reveals that the timing of the end of the first HOPE study (1993-1999) coincided with the release of their drug, Rimipril. The second study results were released in 2005 which was when Aventis released their drug, Plavix.

In The Women’s Health Study, the Times article states that there was no overall benefit in taking 600 IU of vitamin E every other day for cardiovascular health, however the same article goes on to state that there was a 24% reduction in cardiovascular deaths. Upon further analysis of the study, “women who took vitamin E were 21% less likely to develop venous thromboembolism than women who did not, and the reduction was more than double this (44%) along women who had a history of clots. And taking vitamin E also appears to cut the clot risk in half among women with genetic mutations that increased their risks”.

So, what’s at the heart of this discrepancy?

For starters, the vitamin E used in the studies contained only synthetic alpha-tocopherol, and had none of the other components of the natural form of vitamin E. In the Select trial quoted in The New York Times article, a synthetically derived, petroleum-based vitamin E was used, called “all-racemic E.” Natural vitamin E actually refers to a family of at least eight fat-soluble antioxidant compounds, divided into two groups of molecules: tocopherols and tocotrienols. Each of these groups is composed of alpha-, beta-, gamma- and delta forms. And each one of these subgroups has its own unique biological effects. So ideally, vitamin E should be consumed in the broader family of mixed tocopherols and tocotrienols to get the maximum benefits. Several recent studies have shown that natural vitamin E may be up to twice as bioactive as the same amount in synthetic form.

Another possible reason why researchers reported that vitamin E supplements led to a “marginally significant” lower risk of cardiovascular disease is that the researchers from Brigham Women’s Hospital in Boston, where the research for an AMA article was conducted, combined the results from people who consistently took their supplements with people who infrequently took them, diluting the overall findings. When Nancy R. Cook, ScD of the Harvard School of Public Health and her colleagues analyzed data from people who consistently took their supplements, they found that Vitamin E did, in fact, lead to a 22% reduction in the risk of heart attack and a 27% less risk of stroke.

Yet another reason for the different findings could be that in some studies, the amounts of vitamin E used were too little to have significant benefit. According to the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study in The New England Journal of Medicine, “the dose (50 IU of synthetic vitamin E per day) was so low that many observers have attached little meaning to the outcome reported from that trial; however, people with past histories of heart attack assigned to vitamin E alone were reported to have a 38% reduction in non-fatal attacks.” In a 2007 study and commentary in Free Radical Biology and Medicine, researches concluded that “the levels of vitamin E necessary to reduce oxidative stress…are about 1,600 to 3,200 IU daily, or four to eight times higher than those used in almost all past clinical trials.” Similar findings in a Chinese trial were partially dismissed because only 30 IU of vitamin E per day was used.

In conclusion, proper studies of vitamin E must be done carefully and take into account the newest findings about this micronutrient. It is now known that natural forms of the vitamin are far more readily absorbed than synthetic forms.