By Neil E. Levin, CCN, DANLA, Nutrition Education Manager. Conference paper presented at the American Oil Chemists’ Society (AOCS) Hot Topics Symposium. May 2006. Theme: Controversy over the Role of Natural Vitamin E in Reducing Leading Causes of Death. Posted July 2, 2008.
This presentation at the Vitamin E Symposium held during the American oil Chemists society annual meeting in St. Louis, Missouri on May 2, 2006 explored the Vitamin E controversy and how inaccurate news reports create fear of healthy nutrients and undesirable changes in people’s diet and supplementation.
The unconscious biases and the multiplication of variables challenge the designers of review articles, the conclusions of which frequently get trumpeted as overturning all previous scientific studies. But while science is self-correcting, with critical analysis and ability to repeat experiments leading to an enhanced understanding of a field, Media Myths are self-referential and are scarcely dented by subsequent study. In this presentation, the news coverage of Vitamin E was contrasted with its true scientific record.
The warning about taking doses over 400 IU of Vitamin E is largely based on a flawed, heavily criticized meta-analysis that has been largely discredited. (1) A major review in the American Journal of Clinical Nutrition looked at the same data much more carefully, ultimately reporting that doses of up to 1,600 IU daily are safe. (2) The Food and Nutrition Board of the Institute of Medicine sets the upper tolerable intake of Vitamin E at 1,500 IU, showing a strong scientific consensus that lower doses are safe. (3)
Vitamin E reduced cardiac events by 34% in the US Nurses’ Health Study and 39% in the US Health Professionals’ Follow-up Study, also reducing cardiac mortality by 47% in the Iowa Women’s Health Study. (4) Among 90,000 nurses the incidence of heart disease was 30% to 40% lower among those with the highest intake of vitamin E from diet and supplements. Researchers found that the apparent benefit was mainly associated with intake of vitamin E from dietary supplements. (4, 5) The 10-year SENECA study reported blood levels of Vitamin E were not associated with all-cause or cause-specific mortality. (6)
Reports of increased death rates occur mostly in meta-analyses that combine dissimilar studies imperfectly due to faulty statistical models or added variables. This type of review study needs to be critically reviewed before accepting the results, but is rarely definitive. (7)
References:
- Edgar R. Miller, III, MD, PhD; et al. High-dose vitamin E supplementation may increase all-cause mortality, a dose response meta-analysis of randomized trials. Annals of Internal Medicine: Online: Nov. 10, 2004: Print: 4 January 2005 | Volume 142 Issue 1
- John N Hathcock, et al. REVIEW ARTICLE: Vitamins E and C are safe across a broad range of intakes. American Journal of Clinical Nutrition, Vol. 81, No. 4, 736-745, April 2005.
- Food and Nutrition Board, Institute of Medicine. Dietary reference intakes for vitamin C, vitamin E, selenium, and carotenoids. A report of the Panel on Dietary Antioxidants and Related Compounds, Subcommittees on Upper Reference Levels of Nutrients and Interpretation and Uses of Dietary Reference Intakes, and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Washington, DC: National Academy Press, 2000.
- Emmert DH, Kirchner JT. The role of vitamin E in the prevention of heart disease. Arch Fam Med. 1999 Nov-Dec;8(6):537-42.
- Stampfer MJ, et al. Vitamin E consumption and the risk of coronary disease in women. N Engl J Med 1993;328:1444-9
