| 摘要: | 阿茲海默症(Alzheimer's disease，AD)是一種不可逆腦神經退化的疾病，也是失智症的最常見成因。這種疾病影響全球健康問題，無論是對個人和社會皆具有重大影響。造成這個疾病的因素有許多，包括基因變異的問題，生活習慣以及環境的因素等等。症狀包含了記憶減退，個性的改變等認知功能退化，也會因身體功能退化最終會導致死亡。阿茲海默症是一個複雜且多因性的疾病，目前無法完全了解病症的機轉，也沒有任何藥物能夠治癒或是有效緩解病情發展。氧化性壓力導致神經組織產生amyloid (A)胜肽是導致阿茲海默症的主因之一。因此，本研究希望以預防重於治療的概念，針對過去10年對具有抗氧化特性作用的維生素當作研究目標探討這些維生素是否有預防或減緩阿茲海默症發生機率。
本研究採用pubmed及goole學術搜尋引擎，設定搜尋關鍵字包括阿茲海默症、抗氧化劑、維生素C、維生素E、胡蘿蔔素及維生素D等相關之文獻。限制十年內的研究、排除動物實驗，聚焦在人體的臨床試驗文獻，歸納出一百六十四篇，排除重複的文獻，審視各篇摘要最後篩選出符合本研究目的之十四篇作為回顧歸納分析的研究資料來源。
結果顯示具有抗氧化之維生素C與E為文獻中較常見用來研究阿茲海默症之維生素種類，然而目前被收納進來這個研究的這幾篇臨床研究結果顯示，單獨或合併使用維生素C或E對於降低罹患阿茲海默症的機率有的顯示可以降低，但是也有不具成效之結果，因此目前並無結論。相較於已知具有抗氧化能力之維生素C或E，維生素D與阿茲海默症的關係則是近年來漸漸受到重視；本研究收納之文獻結果發現，攝取維生素D不足者罹患阿茲海默症的風險為高，且這些文獻的研究結果較一致。
雖然過去認為具有抗氧化作用的維生素C及維生素E可以降低因氧化壓力產生的 A產量而可能具有預防阿茲海默症的功效，然而臨床試驗的證據並不充足。反之，維生素D在預防或降低罹患阿茲海默症的風險具有較可期待的成效。
Alzheimer's disease (AD) is an un-reversible illness of neurons regression, and the most common type of dementia. This illness is an epidemic issue across the world, and it makes a critical impact on an individual, families and the whole society. There are multiple factors contributing to this illness, including but not limited to genetic divergence, life style, and environment. The symptoms of AD include memory loss, personality change, and others that are related to cognitive functioning regression, which also leads to death due to overall physical functioning decline. AD is a complex and multi-factorial illness where mechanism is still not totally uncovered thus far, and no medication can claim to be a cure or to slow down the progression of the illness effectively. Oxidative stress activating neuro system to produce amyloid β peptide is believed to be one of the main factors to cause AD. Therefore, this thesis is taking a preventative approach by reviewing the research of the past 20 years on examining if antioxidants in vitamins play a role in preventing or slowing down the prevalence of AD.
PubMed and Google Scholar sites were used to search research articles for this thesis. The key words for the research were Alzheimer’s disease, antioxidant, vitamin C, vitamin E, beta carotene, vitamin D, etc. Research done in the past 20 years were included, however any animal related studies were excluded. Among clinical research focused on humans, one hundred sixty-four (164) studies were identified. After removing the repeated studies and reviewing the abstract of each one, fourteen (14) research articles that meet the purpose of this thesis study were chosen to be the target of mega research review analysis.
Through the review vitamins that contain an antioxidant component such as C and E were often used in the research regarding AD. Some research outcomes show that vitamin C or E intake alone respectively or combination of both plays a role of reducing the chance of developing AD. However others show no effect with vitamin C and/or E. Therefore the role of vitamin C or E is inconclusive thus far. Compared to vitamin C and E that are known with an antioxidant component, the relation between vitamin D and AD are getting more and more attention. The result of the articles included in this study shows that people who have deficiency in vitamin D are in higher risk of developing AD. This conclusion is relatively consistent.
In sum, we used to believe that intake of vitamin C and E can have a possible effect of preventing further development of AD because the antioxidant component in those vitamins would reduce the production of amyloid β peptide due to oxidative stress; however the evidences through the clinical trials are not sufficient. On the contrary, vitamin D appears to have potential in preventing or reducing the risk of developing AD. |
