Researchers say vitamin E might slow the progression of mild-to-moderate Alzheimer's disease - the first time any treatment has been shown to alter the course of dementia at that stage.
In a study of more than 600 older veterans, high doses of the vitamin delayed the decline in daily living skills, such as making meals, getting dressed and holding a conversation, by about six months over a two-year period.
The benefit was equivalent to keeping one major skill that otherwise would have been lost, such as being able to bathe without help. For some people, that could mean living independently rather than needing a nursing home.
Vitamin E did not preserve thinking abilities, though, and it did no good for patients who took it with another Alzheimer's medication. But those taking vitamin E alone required less help from caregivers - about two fewer hours each day than some others in the study.
"It's not a miracle or, obviously, a cure," said study leader Dr Maurice Dysken of the Minneapolis VA Health Care System. "The best we can do at this point is slow down the rate of progression."