High doses of vitamin E may help delay the progression of mild to moderate Alzheimer's disease, according to the findings of a new Department of Veterans Affairs study.
The study, published in the Jan. 1 issue of the Journal of the American Medical Association, isn't the first to show the potential benefits of vitamin E for Alzheimer's patients. But many doctors have been hesitant to prescribe the vitamin since a 2005 research paper questioned its safety.
The authors of the VA's study say their findings should put those safety concerns to rest -- at least when it comes to prescribing high-dose vitamin E for Alzheimer's patients.
"I think there's reason to start prescribing it again," said study author Maurice Dysken, the retired director of the Geriatric Research Education and Clinical Centers at the Minneapolis VA Health Care System.
More than 600 patients enrolled in the VA's five-year clinical trial, making it one of the largest and longest studies of vitamin E ever conducted among Alzheimer's patients.
Study participants, who were already receiving standard treatment medication for Alzheimer's, were randomly divided into four groups. One group received 2000 International Units daily of vitamin E alone and another group received vitamin E in combination with the drug memantine, designed to protect nerve cells in the brain from excessive stimulation. A third group received memantine alone, and the final group received a placebo.
The study found that Alzheimer's patients who took high doses of vitamin E alone experienced a slower functional decline than patients in the other study groups. The treatment delayed by an average of six months the deterioration in tasks associated with daily living, such as using the telephone, shopping, keeping track of a checkbook, Dysken said.
The study also found that caregivers spent less time assisting Alzheimer's patients in the vitamin E group. On average their work was reduced by about two hours per day, but the difference was not statistically significant once the authors adjusted their final results.
VA researchers did report a slightly higher frequency of serious infections in the group that received memantine alone and in the group that took memantine in combination with vitamin E, but they didn't find any adverse events associated with taking vitamin E alone.
"We found it to be very, very safe," Dysken said.
The VA findings call in to question the results of a 2005 meta-analysis that found a higher risk of death among people who took high doses of vitamin E.
The researchers who conducted that study based their findings on a review of 19 studies conducted in various patient populations.
"I think it's quite possible that they're both correct," said Denis Evans, an epidemiologic researcher who wrote an editorial in JAMA responding to the VA's study. "With any medication, essentially, there is no free ride."
Evans, also a professor of internal medicine at Rush University Medical Center in Chicago, said it would be "absurd" to conclude that all people could benefit from taking vitamin E in high doses based on the VA study alone. "There might be an increased risk of death," he said.
But for Alzheimer's patients, taking vitamin E "might be worth it" if the compound delays their memory loss for even a few months, Evans said.
The vitamin also has the added allure of being an inexpensive treatment option.
"I actually went to Walgreens just for the fun of it and took a look," Dysken said. "It's about $15 dollars a month for this dose of vitamin E."