Comment: The quality of evidence is downgraded by study quality (high drop-out rate) and imprecise results (few studies in each comparison).
A Cochrane review [Abstract] 1 included 2 studies with a total of 820 subjects. One trial studied patients with Alzheimer's dementia (AD, n = 304) and another people with mild cognitive impairment (MCI, n = 516).In people with AD, there was no evidence of any clinically important effect of vitamin E (alpha tocopherol) on cognition, measured with change from baseline in the Alzheimer's Disease Assessment Scale - Cognitive subscale (ADAS-Cog) over 6 to 48 months (MD -1.81, 95% CI -3.75 to 0.13; 1 study, n = 272). There was no difference between vitamin E and placebo groups in the risk of experiencing at least one serious adverse event (RR 0.86, 95% CI 0.71 to 1.05; 1 study, n = 304), or in the risk of death (RR 0.84, 95% CI 0.52 to 1.34; 1 study, n = 304). People with AD receiving vitamin E showed less functional decline on the Alzheimer's Disease Cooperative Study/Activities of Daily Living Inventory than people receiving placebo at 6 to 48 months (MD 3.15, 95% CI 0.07 to 6.23; 1 study, n = 280). There was no evidence of any clinically important effect on neuropsychiatric symptoms measured with the Neuropsychiatric Inventory (MD -1.47, 95% CI -4.26 to 1.32; 1 study, n = 280).There was no evidence that vitamin E affected the probability of progression from MCI to probable dementia due to AD over 36 months (RR 1.03, 95% CI 0.79 to 1.35; 1 study, n = 516). There was no difference between groups in the more commonly reported adverse events.
Date of latest search:
Primary/Secondary Keywords