Boothby Lisa A, Doering Paul L
Harrison School of Pharmacy, Auburn University, AL, USA.
Ann Pharmacother. 2005 Dec;39(12):2073-80. doi: 10.1345/aph.1E495. Epub 2005 Oct 14.
To evaluate the literature on supplemental vitamin C and vitamin E therapy in the prevention and treatment of Alzheimer's disease (AD).
Literature retrieval was accessed through MEDLINE (1966-March 2005) using the key words antioxidants, vitamin C, vitamin E, Alzheimer's disease, and dementia. International Pharmaceutical Abstracts (1970-March 2005), Current Contents (1996-March 2005), Cochrane Database of Systematic Reviews (1994-March 2005), and Ebsco's Academic Search Elite (1975-March 2005) were searched with the same key words.
Articles related to the objective that were identified through PubMed were included.
Oral supplementation of vitamin C (ascorbic acid) and vitamin E (D-alfa-tocopherol acetate) alone and in combination have been shown to decrease oxidative DNA damage in animal studies in vivo, in vitro, and in situ. Recent results of a prospective observational study (n = 4740) suggest that the combined use of vitamin E 400 IU daily and vitamin C 500 mg daily for at least 3 years was associated with the reduction of AD prevalence (OR 0.22; 95% CI 0.05 to 0.60) and incidence (HR 0.36; 95% CI 0.09 to 0.99). Contradicting this is a previous prospective observational study (n = 980) evaluating the relationship between 4 years of vitamin C and E intake and the incidence of AD, which detected no difference in the incidence of AD during the 4-year follow-up. Recent meta-analysis results suggest that doses of vitamin E > or =400 IU daily for more than one year are associated with increased all-cause mortality. Mega-trial results suggest that vitamin E doses > or =400 IU daily for 6.9 years in patients with preexisting vascular disease or diabetes mellitus increase the incidence of heart failure, with no other outcome benefits noted.
In the absence of prospective, randomized, controlled clinical trials documenting benefits that outweigh recently documented morbidity and mortality risks, vitamin E supplements should not be recommended for primary or secondary prevention of AD. Although the risks of taking high doses of vitamin C are lower than those with vitamin E, the lack of consistent efficacy data for vitamin C in preventing or treating AD should discourage its routine use for this purpose.
评估补充维生素C和维生素E疗法在预防和治疗阿尔茨海默病（AD）方面的文献。
通过MEDLINE（1966年 - 2005年3月）检索文献，使用关键词抗氧化剂、维生素C、维生素E、阿尔茨海默病和痴呆症。使用相同关键词检索国际药学文摘（1970年 - 2005年3月）、现刊目次（1996年 - 2005年3月）、Cochrane系统评价数据库（1994年 - 2005年3月）以及Ebsco的学术搜索精英数据库（1975年 - 2005年3月）。
纳入通过PubMed识别的与该目的相关的文章。
在体内、体外和原位动物研究中，单独及联合口服补充维生素C（抗坏血酸）和维生素E（D-α-生育酚醋酸酯）已显示可减少氧化DNA损伤。一项前瞻性观察性研究（n = 4740）的近期结果表明，每日联合使用400 IU维生素E和500 mg维生素C至少3年与AD患病率降低（OR 0.22；95% CI 0.05至0.60）及发病率降低（HR 0.36；95% CI 0.09至0.99）相关。与之矛盾的是，之前一项评估4年维生素C和E摄入量与AD发病率关系的前瞻性观察性研究（n = 980），在4年随访期间未发现AD发病率有差异。近期的荟萃分析结果表明，每日维生素E剂量≥400 IU且持续超过一年与全因死亡率增加相关。大型试验结果表明，对于已有血管疾病或糖尿病的患者，每日维生素E剂量≥400 IU持续6.9年会增加心力衰竭的发病率，未发现其他有益结果。
在缺乏前瞻性、随机、对照临床试验证明益处超过近期记录的发病和死亡风险的情况下，不应推荐使用维生素E补充剂进行AD的一级或二级预防。尽管服用高剂量维生素C的风险低于维生素E，但缺乏维生素C预防或治疗AD的一致疗效数据，不应鼓励为此目的常规使用。
