Finding a drug to halt or at least slow down the relentless progression of Alzheimer’s disease has been a goal of medical researchers for decades. The results have not been good. Some of the treatments on the market help patients with severe Alzheimer’s—but they don’t help people in the early stages. That’s sad, because these patients still have enough cognitive capacity to see how the disease is inexorably eroding their ability to function and enjoy life.

Now there’s good news: New research shows that vitamin E, which is known to be a powerful antioxidant, can delay the progression in people with early-stage Alzheimer’s—and even help reduce the amount of care they need.

This study involved 613 patients, average age 79, who had mild-to-moderate Alzheimer’s disease. All were being treated with acetylcholinesterase inhibitors (drugs that help control some of the symptoms of Alzheimer’s but do not slow its progression), and some stayed on those drugs for the duration of the study. Patients who were on blood-thinning medication such as warfarin (Coumadin) were excluded from the study because of a potential interaction with vitamin E that could have increased the risk of bleeding.

The patients were randomly divided into four groups. One group was given vitamin E…another group got memantine (Namenda), a drug that reduces abnormal brain activity in moderate-to-severe Alzheimer’s (but does not stop the brain-cell damage the disease causes)…a third group was given both vitamin E and memantine…and the fourth group got a placebo.

At the start of the study and again every six months, participants were evaluated for functional decline using questionnaires (filled out by caregivers) that assessed how well participants could handle daily tasks such as bathing and dressing. Another test determined how much time caregivers spent assisting the patients.

Patients were followed for an average of more than two years. Here’s what the researchers found for each treatment group…

Vitamin E alone: Patients in this group, on average, had a 19% slower annual rate of functional decline than patients who got the placebo. Compared to placebo this translated into a delay in functional decline of 6.2 months over the average follow-up time of 2.3 years. In addition, the amount of time caregivers spent helping patients increased the least in this group—so by the end of the study, patients taking vitamin E required an average of about two hours less assistance per day than those in the other groups. And the vitamin E group had the lowest mortality rate overall, at 7.3% (in comparison, the placebo group’s mortality rate was 9.4%).

Memantine alone: Participants taking this drug showed no benefit compared with placebo users. This group also had the highest mortality rate, at 11.3%.

Vitamin plus memantine: Surprisingly, the combination-therapy group showed no benefit on any of the tests, either. One possible explanation is that the memantine may have interfered with the effectiveness of vitamin E.

The dose of vitamin E used in the study was 2,000 international units (IU) per day of synthetic alpha tocopherol, the most common form of the vitamin. This is a very high dose—nearly 100 times higher than the recommended daily allowance of 22.4 IU and higher even than the 1,500 IU that the government sets as the “tolerable upper intake level,” defined as the maximum daily intake unlikely to cause adverse health effects. Although this study did not show any increase in adverse events among the vitamin E users, high doses of vitamin E do carry an increased risk of bleeding, especially for people who take blood thinners. Also, a large meta-analysis from 2005 showed increased mortality rates among people taking more than 400 IU of vitamin E per day—however, in this new study, vitamin E supplementation was associated with decreased mortality.

Bottom line: If a loved one has mild-to-moderate Alzheimer’s, speak to his/her doctor about the benefits and risks of vitamin E therapy. Also discuss the wisdom of increasing intake of foods rich in vitamin E, such as wheat germ, sunflower seeds, eggs, leafy green vegetables and nuts.