ATMS reports that one of the largest – and lengthiest – studies involving patients suffering mild-to-moderate Alzheimer’s disease has revealed that a daily 2000 international unit (IU) supplement of vitamin E has the power to slow functional decline.

Reported in the January 1, 2014 issue of the Journal of  the American Medical Association (JAMA), the double-blind trial, conducted between 2007 and 2012, involved 613 predominantly male patients at 14 Veterans Affairs medical centres in the US. All of the participants were taking the acetylcholinesterase inhibitor drug donepezil (Aricept) to increase the level and duration of action of the neurotransmitter acetylcholine.

Patients were divided into four roughly equal groups to receive one of the following each day:

• 2000IU vitamin E.
• 20 milligrams of the Alzheimer’s drug memantine (Namenda), a drug that blocks the activity of glutamate to slow the late stages of the disease.
• A combination of vitamin E and memantine.
• A placebo.

During the average follow-up period of 2.3 years the researchers, lead by Maurice Dysken M.D., a research scientist at the Minneapolis V A Health Care System, monitored changes in participants’ functional decline. Defined as the patient’s lack of ability to carry out everyday tasks without assistance, functional decline has a significant impact on a patient’s quality of life in addition to imposing a strain on social and economic costs.

Using the Alzheimer’s Disease Cooperative Study/Activities of Daily Living, the researchers looked at aspects such as:

• The person’s ability to perform activities of daily living.
• Their cognitive function.
• Memory and language.
• Psychological and behavioural problems.
• Time necessitating caregiver assistance.

Surprising results

The results were surprising. The drug memantine taken alone, or in combination with vitamin E, produced no benefits. However, when vitamin E was taken alone functional decline slowed by 19 per cent compared with patients who received the placebo. This translates to what the researchers describe as a “clinically meaningful delay in progression of 6.2 months.”

Moreover, those in vitamin-only group needed two hours less assistance from a caregiver each day. Dr Dysken remarked that this could represent the difference between patients who can still dress or bathe independently and those who cannot.

This is the first large-scale clinical trial to assess not only the effectiveness of alpha tocopherol in patients with mild-to-moderate Alzheimer’s disease, but also the combination of alpha tocopherol and memantine.

The research team pointed out that in contrast to the conclusion drawn from a 2005 meta-analysis of vitamin E, which showed high-dose vitamin E may actually increase the risk of all-cause mortality, this study found no significant increase in mortality with vitamin E. The annual mortality rate was 7.3 per cent in the alpha tocopherol group, compared with 9.4 per cent for the placebo group.

In fact, the finding of this study adds weight to previous studies investigating the use of alpha tocopherol in patients with severe Alzheimer’s disease, including one 1997 study that revealed that a 2000IU dose of the antioxidant vitamin was effective in slowing progression of moderately severe Alzheimer’s disease.