Does Vitamin E Increase Heart Failure Risk?
Despite vitamin E’s long-held reputation of being “good for the heart,” many doctors and scientists may now recommend that people not take vitamin E for the purpose of preventing heart disease, due to a recent study published in the Journal of the American Medical Association (2005;293:1338–47) suggesting that taking vitamin E could increase the risk of developing heart failure and an earlier report suggesting that using large doses of vitamin E causes a small increase in death rates. However, there are good reasons to believe this recommendation is premature and that taking the right form of vitamin E is not dangerous to health and may still be considered useful for preventing heart disease and other illnesses.
Though vitamin E is found in food in four different forms—alpha-, beta-, gamma-, and delta-tocopherol—virtually all of the clinical research on vitamin E has used pure alpha-tocopherol. While early research suggested that most, if not all, of the biological activity of vitamin E resides in the alpha- fraction, it is now known that at least one of the other components—gamma-tocopherol—has important functions. Furthermore, treatment with large doses of alpha-tocopherol has been shown to deplete gamma-tocopherol, potentially upsetting the natural balance of the different forms of vitamin E in the body. “Mixed tocopherols,” on the other hand, which contain all four types of vitamin E, would not be expected to cause such an imbalance.
Alpha-tocopherol has a number of properties that might make it useful for preventing heart disease. It inhibits platelet aggregation and possibly other mechanisms of blood clotting, inhibits the oxidation of LDL (“bad”) cholesterol (one factor that promotes hardening of the arteries, or atherosclerosis), prevents the development of atherosclerosis in laboratory animals, and reduces the adverse consequences of poor blood circulation in both animals and humans. Alpha-tocopherol has been said to be beneficial in the prevention of blood clots following surgery, and in the treatment of many different cardiovascular conditions, including angina, congestive heart failure, intermittent claudication (calf pain on walking), ulcers caused by impaired circulation, and gangrene. However, much of the evidence has been anecdotal, and reports have often been conflicting. On the other hand, the effectiveness of alpha-tocopherol against intermittent claudication and for preventing postoperative blood clots is supported by controlled trials, and the results have been fairly consistent.
While supplementing with alpha-tocopherol appears to be beneficial for some people, for others the benefits might be diminished or even outweighed by a relative deficiency of gamma-tocopherol. Recent studies have shown that gamma-tocopherol performs certain functions in the body more effectively than alpha-tocopherol, and some of these actions would presumably reduce the risk of heart disease.
The potential for alpha-tocopherol to deplete gamma-tocopherol is particularly relevant to the issue of congestive heart failure. When metabolized by the body, gamma-tocopherol changes into a compound that appears to function as a hormone which regulates fluid and salt balance in the body (natriuretic hormone). Proper regulation of water and salt balance is necessary to prevent excessive stress being placed on the heart following a salty meal. It is possible that, for some people, alpha-tocopherol-induced gamma-tocopherol deficiency would make the heart work harder under certain circumstances, and possibly cause an already weak heart to “wear out” sooner. (Of note, the study that showed an increased risk of heart failure with high-dose alpha-tocopherol was done with people who already had, or were at high risk of developing, heart disease. People with normal hearts would probably be less likely to experience any negative consequences from taking high-dose alpha-tocopherol.)
Alpha-tocopherol alone may not benefit everyone, and the available evidence suggests that mixed tocopherols are preferable to alpha-tocopherol, both in terms of safety and efficacy. Until the alpha-tocopherol research is repeated using mixed tocopherols, the question of whether or not vitamin E is “good for the heart” will remain open. Mixed tocopherols can be taken in supplement form; they are also found in foods such as whole grains, nuts and seeds, eggs, green leafy vegetables, and vegetable oils.
Alan R. Gaby, MD, an expert in nutritional therapies, testified to the White House Commission on CAM upon request in December 2001. Dr. Gaby served as a member of the Ad-Hoc Advisory Panel of the National Institutes of Health Office of Alternative Medicine. He is the author of Preventing and Reversing Osteoporosis (Prima, 1994), and co-author of The Natural Pharmacy, 2nd Edition (Healthnotes, Three Rivers Press, 1999), the A–Z Guide to Drug-Herb-Vitamin Interactions (Healthnotes, Three Rivers Press, 1999), Clinical Essentials Volume 1 and 2 (Healthnotes, 2000), and The Patient’s Book of Natural Healing (Prima, 1999). A former professor at Bastyr University of Natural Health Sciences, in Kenmore, WA, where he served as the Endowed Professor of Nutrition, Dr. Gaby is the Chief Medical Editor for Healthnotes, Inc.
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