Razali Rabiatul Adawiyah, Ngah Wan Zurinah Wan, Makpol Suzana, Yanagisawa Daijiro, Kato Tomoko, Tooyama Ikuo
Medical Innovation Research Center (MIRC), Shiga University of Medical Science, Otsu 520-2192, Shiga, Japan.
Department of Biochemistry, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia.
Int J Mol Sci. 2025 Jun 30;26(13):6339. doi: 10.3390/ijms26136339.
Vitamin E has been extensively studied for its neuroprotective properties, with increasing evidence supporting its broader roles in brain health. This scoping review aims to systematically identify, analyze, and synthesize evidence of the existing literature over the last 10 years on tocotrienol and tocopherol supplementation in humans. A systematic search was conducted across PubMed, Scopus, and EBSCOhost yielding 42 eligible articles. Findings suggest that tocopherols, especially α- and γ-forms, are associated with improved cognitive performance, reduced neuroinflammation, and preservation of synaptic proteins. Despite tocotrienol's lower plasma bioavailability, tocotrienol availability in selective brain regions has been associated with structural protection, particularly in white matter. Both compounds exhibit complementary effects, suggesting a potential advantage of combined supplementation. However, heterogeneity in study designs, subject characteristics, dosage, duration, and assessment methods limit direct comparisons and generalizability of findings. Based on our review's findings, further research such as dose-optimization, long-term exposures, and delivery methods on human studies should be performed. This review highlights the multifaceted roles of vitamin E in brain health and underscores the urgent need for well-designed studies to clarify the distinct and synergistic effects of tocopherols and tocotrienols, particularly in human populations.
维生素E因其神经保护特性已得到广泛研究，越来越多的证据支持其在大脑健康中发挥更广泛的作用。本综述旨在系统地识别、分析和综合过去10年中关于人类补充生育三烯酚和生育酚的现有文献证据。我们在PubMed、Scopus和EBSCOhost数据库中进行了系统检索，共获得42篇符合条件的文章。研究结果表明，生育酚，尤其是α-和γ-形式，与认知能力改善、神经炎症减轻以及突触蛋白的保留有关。尽管生育三烯酚的血浆生物利用度较低，但在选择性脑区的生育三烯酚可用性与结构保护有关，尤其是在白质中。这两种化合物表现出互补作用，表明联合补充可能具有潜在优势。然而，研究设计、受试者特征、剂量、持续时间和评估方法的异质性限制了研究结果的直接比较和普遍性。基于我们综述的结果，应开展进一步的人体研究，如剂量优化、长期暴露和给药方法等。本综述强调了维生素E在大脑健康中的多方面作用，并强调迫切需要设计良好的研究来阐明生育酚和生育三烯酚的独特和协同作用，特别是在人群中的作用。
