BACKGROUND: Vitamin E was discovered 80 years ago and is best known as an antioxidant that may reduce oxidative stress associated with the development of coronary heart disease. Although the totality of research supports health benefits from vitamin E, many scientists have been puzzled by the conflicting findings of recent clinical trials.
RESEARCH: A group of leading vitamin E researchers reviewed much of the scientific evidence on the role of vitamin E in human health and disease prevention. They evaluated the various forms of vitamin E in terms of absorption, transport and metabolism. They noted that most researchers have focused on the antioxidant properties of vitamin E, rather than what else vitamin E might be doing in tissues. Vitamin E has many important non- antioxidant functions in the body that are just starting to be understood, such as anticoagulant (blood thinning) properties, anti-inflammatory action, effects on gene regulation and immune function.
RESULTS: The researchers noted that the clinical trials of vitamin E in heart disease were designed to observe the reversal rather than the prevention of disease, and disease reversal is likely to require a different strategy than antioxidant protection for prevention. They also pointed out that each study differed in many aspects, such as dosage, sources of vitamin E, and study populations (age, gender and location), problems which make comparisons difficult and may have led to inconsistent findings. Nonetheless, most of the clinical trials showed some benefit of vitamin E in reducing the risk of heart attack or cardiovascular death, even though the type of benefit was not always identical. In addition, vitamin E supplements, as antioxidants or through other mechanisms, may reduce the risk of prostate cancer and be of benefit in people with either cystic fibrosis or preclampsia.
IMPLICATIONS: Although many scientific questions remain with regard to vitamin E supplements and the design of studies, the research so far shows a great deal of promise. The researchers concluded that eighty years after the discovery of vitamin E, "it is time to take it more seriously and undertake the research needed to determine what makes it a real vitamin."
Brigelius-Flohe R, Kelly FJ, Salonen JT, et al.,"The European perspective on vitamin E: current knowledge and future research," American Journal of Clinical Nutrition, 2002;76:703-716.
For the original abstract, visit: http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12324281&dopt=Abstract