As in last year’s case, I must defend vitamin E once again.
At least this time, it was a study, not a meta-analysis. The study appeared in this week’s Journal of the American Medical Association.
The authors from the HOPE TOO trial conclude that 400IU of vitamin E showed no heart or cancer protective benefits, and actually may increase heart attack risk in women over age 55, compared to the placebo. While the authors admit that there was not a definitive conclusion to this study, except to state that more studies were needed, and the supposed observation of an adverse event in this trial cannot be confirmed by any other trials, the result may still be a shock to you.
Let’s look at the details of the study:
1) It is important to note that those participating in the study suffered from a range of degenerative diseases including vascular disease or diabetes mellitus, and at least one other significant cardiovascular risk factor. A 400IU dose of vitamin E is too small to show any reversal of serious conditions such as these.
2) Furthermore, subjects in this study were typically taking five different medications in addition to the 400IU of vitamin E, including beta-blockers, anti-platelet agents, statins, diuretics, calcium channel blockers, and ACE inhibitors – yet, the heart failure was attributed exclusively to vitamin E, with no adjustment for pharmacotherapy.
If I attempted to construct a study like this when I was in the University of Illinois-Chicago School of Public Health Masters program, I would have been flunked. The medications are considered confounding variables and must be adjusted for. All the medications used by people in the study list heart failure as a side effect.
There are three studies in Diabetes Care, the journal of the American Diabetes Association, that contradict this recent discovery.
1) The same HOPE TOO study concluded in 2002 that while vitamin E did not improve the outcomes of the participants in the trial, it did not worsen their outcomes.
2) A 11/2004 study that appeared in Diabetes Care showed that 40% of diabetic patients (with no other conditions) can reduce their risk of heart attacks (by 43%) and of dying from heart disease (by 55%) by taking vitamin E supplements at a 400IU dose.
3) A 12/2004 study that appeared in Diabetes Care followed overweight adults given 800IU of vitamin E for 90 days and increasing to 1200IU for another 90 days. Their blood markers of oxidative stress (which contributes to insulin resistance) fell by 27 at three months and 29 percent at six months.
Another study that appeared in the March 2nd, 2005 issue of the Journal of the National Cancer Institute found that prostate cancer risk may be cut significantly when alpha- and gamma-tocopherol, the two most prominent components of vitamin E, are present in high levels in the blood.
According to an analysis of 100 patients with prostate cancer and 200 who were cancer-free, among 30,000 Finnish men, those with the highest levels of alpha-tocopherol in their blood at baseline were 51 percent less likely to develop prostate cancer. Those who had the same high levels of gamma-tocopherol were 43 percent less likely to be stricken with the disease. The link between high tocopherol levels and the reduced prostate cancer risk was stronger among patients using alpha-tocopherol supplements than among non-users.
As in last year’s Hopkins meta-analysis study, we are unaware if the JAMA study used one particular form of Vitamin E, namely alpha-tocopherol, which is only one part of the vitamin E picture. A convincing body of evidence now points to the fact that alpha-tocopherol in supplements, particularly at high doses, might reduce the body's uptake of vital components of Vitamin E which are much more effective antioxidants than alpha-tocopherol, such as, gamma- and beta-tocopherols, and tocotrienols (e.g. Handelman GJ et al,J Nutr 115; 807-13,1985; Burton GH et al,Am J Clin Nutr67; 669-84, 1998; Huang HY, Appel LJ.J Nutr 133; 3137-40, 2003.). This is why we always recommend a mixed tocopherol when taking supplemental vitamin E.
Years of clinical research show that Vitamin E supplementation is safe. This has been clearly documented in recent clinical trials including:
-Morris CD, Carson S. Routine vitamin supplementation to prevent
cardiovascular disease: a summary of the evidence for the U.S.
Preventive Services Task Force. Ann Intern Med. 2003;139:56-70.
-Vivekananthan DP, Penn MS, Sapp SK, Hsu A, Topel EJ. Use of
antioxidant vitamins for the prevention of cardiovascular disease:
meta-analysis of randomized trials. Lancet. 2003;361:2017-23.
-Shekelle PG, Morton SC, Jungvig LK, Udani J, Spar M, Tu W, et al.
Effect of supplemental vitamin E for the prevention and treatment of
cardiovascular disease. J Gen Intern Med. 2004;19:380-9.
The highly respected, independent organization Institute of Medicine finds, "Vitamin E mixed tocopherol supplements are safe at levels of at least up to 1,000 mg (1,600 IU) for normal, healthy adults."
I echo this statement.
Have a happy, healthy day.
Bonnie Minsky, MA, MPH, LDN, CNS