Vitamin E, including its mixed tocotrienols and tocopherols forms, has been studied for its potential role in supporting or treating dementia, particularly Alzheimer’s disease. The rationale for its use is based on Vitamin E’s antioxidant properties, which could theoretically protect neural tissues from oxidative damage associated with neurodegenerative diseases. Some early observational studies and small clinical trials suggested that higher Vitamin E intake might be associated with a lower risk of cognitive decline.

However, larger randomized controlled trials have yielded mixed results. The most notable is the TEAM-AD VA Cooperative Randomized Trial (2014), which found that high-dose alpha-tocopherol (2000 IU/day) modestly slowed functional decline in patients with mild to moderate Alzheimer's disease compared to placebo. Yet, the effect on cognition was less clear, and some studies have failed to replicate these benefits. Additionally, high-dose Vitamin E supplementation has raised safety concerns, particularly regarding increased risk of hemorrhagic stroke and all-cause mortality in some populations.

Overall, while there is some scientific basis for the use of Vitamin E in dementia, the evidence is not strong or consistent enough for widespread recommendation. Most guidelines do not endorse routine use of Vitamin E for dementia prevention or treatment due to these mixed findings and potential risks.