December 31st, 2013
04:00 PM ET
There is no cure for Alzheimer's, nor is there an effective method of reversing symptoms such as memory loss, disorientation and difficulties in organizing thoughts. But a new study in the Journal of the American Medical Association suggests there may be some hope for improvement in these patients, in the form of vitamin E.
The study authors say that this is the first demonstration of vitamin E benefiting Alzheimer's patients with mild to moderate disease. However, they caution that it doesn't prove that the vitamin is always effective and therefore should not be universally recommended.
“This is a well done study by a solid research group," said Maria Carrillo, vice president of Medical and Scientific Relations at the Alzheimer’s Association, in a statement. "The results are positive enough to warrant more research to replicate and confirm these findings, but should not change current medical practice. No one should take vitamin E for Alzheimer’s except under the supervision of a physician."
The trial involved 613 patients with mild to moderate Alzheimer's disease. The subject pool does not reflect the general population, since 97% of participants were male. All but one of them were already taking drugs called acetylcholinesterase inhibitors, which slows the progression of Alzheimer's symptoms in some people.
Participants were divided into four groups: (1) receive synthetic vitamin E, (2) receive a drug called memantine, (3) receive both vitamin E and memantine, (4) receive a placebo. Memantine is a drug that is approved by the U.S. Food and Drug Administration for moderate to severe Alzheimer's but, like acetylcholinesterase inhibitors, they don't work for everyone and do not reverse the course of the disease.
To evaluate progress, researchers used a tool called the Alzheimer's Disease Cooperative Study/Activities of Daily Living Inventory, which measures functional ability. Other assessments were also used to look at cognitive outcomes.
Patients were followed for an average of 2.3 years.
Researchers found that participants in the vitamin E-only group had a delay in clinical progression of the disease of 19% over a year, compared with those in the placebo group. When researchers measured how quickly their Alzheimer's was progressing in terms of daily living activities, those in the vitamin E-only group saw their disease decline 3.15 units less on the testing tool than those receiving placebo. This signifies a loss of independence - for instance, the authors wrote, losing 3 points could mean not being able to dress or bathe oneself independently anymore.
Activities of daily living are rarely shown to improve in clinical trials, so that is a strength of the study, said Dr. Scott Small, director of the Alzheimer's Disease Research Center at Columbia University Medical Center, who was not involved in this study.
But individuals who took the combination vitamin E and memantine, or memantine alone, did not show average benefits over the placebo group. None of the treatment groups did better than the placebo group on the cognitive tests.
Some results don't completely add up, Small said.
For him, the finding that vitamin E by itself showed benefits, but in combination with memantine it did not, is puzzling. There is also the question of why none of the treatment groups did better than the placebo group in cognitive abilities.
“It is unclear why there were functional but not cognitive benefits of this intervention. The lack of cognitive benefit re-emphasizes the need for replication and confirmation of these results before considering this as a treatment strategy,” Carrillo said.
Vitamin E had been shown in previous research to possibly benefit Alzheimer's patients, but other studies have raised safety concerns. Among them was a 2011 JAMA study that found dietary supplementation with vitamin E in healthy men increases the risk of prostate cancer.
In this new study, vitamin E did not appear to increase the likelihood of mortality. None of the treatments seemed to be unsafe, according to this research, but "the size of the study did not allow us to detect infrequent but potentially significant adverse events," the researchers wrote.
It's important for the study to be replicated, so that the results can be confirmed, but this is a good step toward positively intervening in the disease, Small said.
"I think clinicians will now start considering vitamin E," says Small. It's something he might consider recommending for some of his patients. But because there is no drug that makes a significant difference in the well-being of Alzheimer's patients, Small adds, doctors must have open discussions with patients about the various strategies that are available, which might or might not work, and have pros and cons associated with them.
"In the future there will be very little discussion when we have a clearer, yes-or-no answer," he said.
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