TUESDAY, Dec. 31, 2013 (HealthDay News) -- There might be some good news in the fight against Alzheimer's disease: A new study suggests that a large daily dose of vitamin E might help slow progression of the memory-robbing illness.
Alzheimer's patients given a "pharmacological" dose of vitamin E experienced slower declines in thinking and memory and required less caregiver time than those taking a placebo, said Dr. Maurice Dysken, lead author of a new study published Dec. 31 in the Journal of the American Medical Association.
"We found vitamin E significantly slowed the rate of progression versus placebo," said Dysken, who is with the Geriatric Research Education and Clinical Center of the Minneapolis VA Health Care System.
Experts stressed, however, that vitamin E does not seem to fight the underlying cause of Alzheimer's and is in no way a cure.
The study involved more than 600 patients at 14 VA medical centers with mild to moderate Alzheimer's. Researchers split the group into quarters, with each receiving a different therapy.
One-quarter received a daily dose of 2,000 international units (IU) of alpha tocopherol, a form of vitamin E. That's a relatively large dose; by comparison, a daily multivitamin contains only about 100 IUs of vitamin E, Dysken said.
The other sets of patients were given the Alzheimer's medication memantine, a combination of vitamin E and memantine, or a placebo.
People who took vitamin E alone experienced a 19 percent reduction in their annual rate of decline compared to a placebo during the study's average 2.3 years of follow-up, the researchers said.
In practical terms, this means the vitamin E group enjoyed a more than six-month delay in the progression of Alzheimer's, the researchers said.
This delay could mean a lot to patients, the researchers said, noting that the decline experienced by the placebo group could translate into the complete loss of the ability to dress or bathe independently.
The researchers also found that people in the vitamin E group needed about two fewer hours of care each day.
Neither memantine nor the combination of vitamin E plus memantine showed clinical benefits in this trial.
Therapy with vitamin E also appears to be safe, with no increased risk of illness or death, the researchers found. The annual death rate was 7.3 percent for people in the vitamin E group and 9.4 percent for those on placebo.
People should keep in mind, however, that vitamin E taken at such large doses can have an effect on other medications, said Heather Snyder, director of medical and scientific operations for the Alzheimer's Association.
"We know there might be some interactions with other medications that people might be taking, including blood thinners or cholesterol medications," Snyder said. That means that people who want to take vitamin E to treat Alzheimer's should do so under the supervision of their doctor, Dysken and Snyder said.
Snyder said the findings are "certainly positive enough to warrant further research," but she'd like to see the study replicated with another set of patients. The patients in this study were nearly all male, so were not wholly representative of the general public.
Research also needs to be done to figure out why vitamin E helps Alzheimer's patients, both Snyder and Dysken said.
At this point, no one is sure how it helps slow mental decline. The vitamin E used in the study is a fat-soluble antioxidant, but "we don't have a cogent theory why that property should be positive in patients with Alzheimer's disease," Dysken said.
However, such research into treating Alzheimer's might not be as potentially beneficial as studies that focus on preventing the disease altogether, Dr. Denis Evans, of Rush University Medical Center in Chicago, wrote in an editorial that accompanied the study.
"This is an excellent trial, and it points out the limitations of finding ways to treat the disease," Evans said. "It's a reasonable argument for putting more emphasis on prevention. If you look at all trials of Alzheimer's disease, of which this is an example of one of the best, the treatment effects are real but they are also relatively small and they focus [only] on the symptoms of the disease."
For more information on vitamin E and Alzheimer's disease, visit the Alzheimer's Association.