WASHINGTON, Dec 14, 2004 -- Researchers from the Harvard School of Public Health and the American Cancer Society have found that vitamin E may play an important role in the prevention of the devastating motor neuron disease ALS (amyotrophic lateral sclerosis), according to the Council for Responsible Nutrition. The study is currently available online (http://www3.interscience.wiley.com/cgi-bin/jissue/78504407) in advance of print publication in the January issue of Annals of Neurology.
This prospective study which tracked 957,740 persons 30 years old or over for 10 years was funded by a grant from the National Institutes of Health. During the follow-up, 525 participants in the study died of ALS. The purpose of the research was to see whether vitamin E reduces the risk of developing ALS in humans. Although in previous studies vitamin E did not prolong survival of ALS patients, it was not known whether regular use of this vitamin supplement by healthy individuals could prevent the disease. In animal studies, early administration of vitamin E was found to delay the onset but not the progression of ALS.
The investigators found that those individuals who took vitamin E supplements for at least 10 years had a risk of death from ALS that was less than half that of those who did not use vitamin E. In contrast, no significant associations were found for use of vitamin C or multivitamin supplements. The researchers speculate that the lower mortality that they observed among vitamin E users was most likely caused by a reduction in ALS incidence rather than an improved prognosis. The multi-institutional research team was headed by Alberto Ascherio, M.D., of the Harvard School of Public Health.
Information on vitamin use was gathered when participants first enrolled in 1982. Follow-up of over 170,000 participants in 1992 confirmed that most regular vitamin E users were still using the supplement 10 years later.
Dr. Ascherio said, "Vitamin E has been known to slow the onset of ALS in animal studies. We were interested to see if humans who regularly use supplements of both the antioxidant vitamins E and C have a lower risk of ALS than nonusers do. We found that regular use of vitamin E was associated with a lower risk of dying of ALS." Antioxidant vitamin E appears to protect against the disease by reducing oxidative stress and the damage it causes throughout the body.
More research needs to be done, said Dr. Ascherio, including whether vitamin E has an effect on preventing familial ALS, and the possibility of interaction between vitamin E consumption and an individual's lifestyle. In this study vitamin E users had healthier lifestyles than nonusers, but this difference did not explain the apparent benefit of vitamin E.
"There may also be a synergy between vitamin E and the other supplements that vitamin E users take, because people who take vitamin E tend also to use other supplements. But there is insufficient evidence to determine whether vitamin E has to be combined with anything else. Our research shows that vitamin E is the only one specifically associated with a lower risk of ALS, but this does not exclude interactions with other factors," said Dr. Ascherio, who added, "Our results are encouraging, but insufficient to recommend any change in vitamin E intake. We are planning a new investigation that will provide more definitive evidence on whether vitamin E may contribute to ALS prevention."
Ascherio A, Weisskopf MG, O'Reilly EJ, et al. Vitamin E intake and risk of amyotrophic lateral sclerosis. Ann Neurol 2005 Jan; 57(1):104-110.
Note to Editor: The Council for Responsible Nutrition (CRN), founded in 1973, is a Washington, D.C.-based trade association representing dietary supplement industry ingredient suppliers and manufacturers. CRN members adhere to a strong code of ethics, comply with dosage limits and manufacture dietary supplements to high quality standards under good manufacturing practices. For more information on CRN, visit http://www.crnusa.org