While vitamin E and memantine have known benefits for those with moderately severe Alzheimer’s disease (AD), the effects on mild to moderate AD have been limited. Researchers set out to determine if alpha tocopherol, memantine or both could slow progression of mild to moderate AD in patients taking an acetylcholinesterase inhibitor.
In a double-blind, placebo-controlled, parallel-group, randomized clinical trial, 613 patients with mild to moderate AD received either 2,000 IU/day of alpha tocopherol, 20 mg/day of memantine, the combination or placebo. Those participating from August 2007 through September 2012 were then evaluated using an Alzheimer’s Disease Cooperative Study/Activities of Daily Living (ADCS-ADL) inventory score, as well as secondary data including cognitive, neuropsychiatric, functional and caregiver measures.
Data from 561 participants were analyzed (52 were excluded because of lack of follow-up data) and found that ADCS-ADL inventory scores declined by 3.15 units in the alpha tocopherol group compared with the placebo group. In the memantine group, these scores declined 1.98 units less than the placebo group’s decline.
According to researchers, this change in the alpha tocopherol group translated into a delay in clinical progression of 19% per year compared with placebo, or a delay of approximately 6.2 months over the follow-up period. Furthermore, reported caregiver time increased least in the alpha tocopherol group.
Duffy MacKay, ND, senior vice president, scientific and regulatory affairs, Council for Responsible Nutrition (CRN), commented on the findings, “This study is significant as it presents strong data on the safety of vitamin E, at high doses, and dismisses previous questions raised about the safety of this essential nutrient. The authors stated, ‘In contrast to the conclusion drawn from a 2005 meta-analysis of vitamin E, which showed that high-dose vitamin E (≥400 IU/day) may increase the risk of all-cause mortality, we found no significant increase in mortality with vitamin E.’ This new study demonstrates that scientists seeking to slam the door on vitamins, and new vitamin research, is the antithesis of what science is all about.”