Effect of vitamin E on cerebrovascular function: a systematic review

Objectives: Cerebrovascular function declines with normal ageing, and the antioxidant and anti-inflammatory properties of Vitamin E may maintain or improve this. The aim of this systematic review is to evaluate the effect of vitamin E on cerebrovascular function in both pre-clinical and clinical populations.Methods: Six databases (PubMed, MEDLINE, Web of Science, Scopus, ScienceDirect, and CINAHL) were searched in 2024 using keywords such as 'vitamin E', tocopherol, tocotrienol, 'cerebrovascular function', and related medical subject heading terms.Results: Of the 335 records returned, no clinical studies were identified. Ten pre-clinical studies met the inclusion criteria and were included for analysis. Due to heterogeneity in study designs and outcomes, a meta-analysis was not performed. Across animal models of cerebral ischaemia and haemorrhagic hypoperfusion, vitamin E supplementation improved cerebral blood flow, reduced intracranial pressure, and enhanced cerebrovascular responsiveness, thus reflecting improved cerebrovascular function. Furthermore, studies examining platelet aggregation reported delayed thrombus formation, likely mediated by reduced oxidative stress and improved endothelial function and nitric oxide bioavailability. However, with heterogeneous outcomes from pre-clinical studies and a lack of clinical studies, the translatability of data to the effect of chronic consumption on cerebrovascular function in humans is limited.Discussion: Pre-clinical data suggest that the antioxidant capacity of vitamin E and its regulatory effect on platelet aggregation may improve cerebrovascular function. However, the absence of clinical data limits translation to human populations. Future well-designed studies in older adults are warranted to determine whether vitamin E supplementation can preserve or improve cerebrovascular function throughout the ageing process.