Association of vitamin E intake in diet and supplements with risk of dementia: A meta-analysis

BACKGROUND: Dementia is a chronic progressive neurodegenerative disease that can lead to disability and death in humans, but there is still no effective prevention and treatment. Due to the neuroprotective effects of vitamin E, a large number of researchers have explored whether vitamin E can reduce the risk of dementia. Some researchers believe that vitamin E can reduce the risk of dementia, while others hold the opposite conclusion. We therefore performed a meta-analysis to clarify the relationship between them. METHODS: We searched PubMed, Embase, and Web of Science databases for articles on the connection of dietary and supplementation vitamin E with dementia risk from inception through April 2022 using the main keywords “dementia,” “Alzheimer's disease,” “vitamin E,” and “tocopherol,” and used a random-utility model for pooled effect sizes. Odds ratios (OR) and 95% confidence intervals were derived using lower and higher doses as contrasts. Obtained data were shown and assessed using Stata12.0 free software. RESULTS: We included 15 articles in sum. Among them, there were nine articles containing AD. By comparing the highest intake with the lowest intake, Combined ORs for high intake were as follows: dementia (OR = 0.79, 95% CI 0.70–0.88 I(2) = 35.0%), Alzheimer's disease (OR = 0.78, 95% CI 0.64–0.94 I(2) = 36.9%). Subgroup analyses were also performed by study type, diet and supplementation, and NOS score. CONCLUSIONS: High vitamin E intake from diet and supplements significantly reduces the risk of dementia and Alzheimer's disease.