A new U.S. study reports that vitamin E supplementation may slow progression of mild to moderate Alzheimer’s disease.
The randomized controlled trial measured the decline of functional abilities to perform activities of daily living in 613 patients with mild to moderate Alzheimer’s disease (AD). The patients received either 2000 IU/day of vitamin E (alpha-tocopherol), 20 mg/day of an AD medication (memantine), a combination of the two or a placebo for a mean of over two years (1). The study results showed that participants who received vitamin E had a slower decline in functional abilities than those who received the placebo. The change translated into a delay in clinical progression of 19% per year compared with the placebo. In addition, the vitamin E group needed less caregiver time (approximately 2 hours per day). There were no significant differences in the groups receiving memantine alone or the drug plus vitamin E.
The researchers commented that in addition to a significantly delayed clinical progression of AD, the reduc- tion of caregiver time through vitamin E treatment could have a major effect on informal and direct medical care costs. Decline in functioning in AD is increasingly recognized as an important determinant of both pa- tient quality of life and social and economic costs. Maintaining the ability to perform activities of daily living is very important to patients and to caregivers. In contrast to an earlier meta-analysis, which speculated that vitamin E doses above 400 IU/day may increase the risk of long-term all-cause mortality (2), the high vita- min E dose in the study was shown to be safe. In patients with moderately severe AD, vitamin E (2000 IU/d) had already shown to be effective in slowing clinical progression (3). Vitamin E is thought to protect cells from oxidative damage and to stabilize cell membranes due to its antioxidant abilities. At high doses, enough vitamin E may reach the brain to protect against the brain cell death that characterizes AD.