Vitamin E may slow functional decline in patients with mild to moderate Alzheimer's disease

Taking 2,000 IU of vitamin E daily slowed functional decline and reduced caregiver time in patients with mild to moderate Alzheimer's disease, a study found.

Researchers examined the effectiveness and safety of vitamin E, memantine, and the combination for treatment of functional decline in patients with mild to moderate Alzheimer's disease who were taking an acetylcholinesterase inhibitor.

The trial included 613 patients at 14 Veterans Affairs medical centers, with 52 later excluded for a lack of follow-up data. Participants were randomized to receive either 2,000 IU of vitamin E daily (n=140), 20 mg of memantine daily (n=142), both (n=139) or placebo (n=140). Change in functional decline was measured via the Alzheimer's Disease Cooperative Study/Activities of Daily Living (ADCS-ADL) Inventory score (range, 0 to 78).

Results appeared in the Jan. 1 Journal of the American Medical Association.

Over the mean follow-up of 2.27 years, ADCS-ADL Inventory scores declined by 3.15 units (95% CI, 0.92 to 5.39; adjusted P=0.03) less in the vitamin E group compared with the placebo group. In the memantine group, these scores declined 1.98 units less (95% CI, −0.24 to 4.20; adjusted P=0.40) than in the placebo group. The researchers noted that the difference in the vitamin E group translates into a 19% per year delay in clinical progression compared to the placebo group, or a delay of about 6.2 months during the study's follow-up period. Caregiver time was also reduced by 2.17 hours per day (95% CI, 0.63 to 3.71 hours per day) in the vitamin E group compared with the memantine group.

All-cause death and safety analyses showed a difference only on the serious adverse event of “infections or infestations,” with greater frequencies in the memantine (31 events in 23 participants) and combination groups (44 events in 31 participants) compared with placebo (13 events in 11 participants).

The researchers noted that decline in functioning in Alzheimer's disease is increasingly recognized as an important determinant of both patient quality of life and social and economic costs. The difference in function between groups could mean retaining the ability to dress or bathe independently for some patients, they noted. “Because vitamin E is inexpensive, it is likely these benefits are cost-effective as alpha tocopherol improves functional outcomes and decreases caregiver burden,” the authors wrote.

An editorial noted that as with almost all previous trials, the therapeutic effect seen was modest and more relevant to symptoms and consequences than to reversal of the disease process. “Considering the difficulties inherent in trying to treat rather than prevent very high-prevalence diseases and the limitations thus far of the therapeutic efforts for people with [Alzheimer's disease], shifting to more emphasis on prevention seems warranted,” the editorial stated.