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维生素B不可能会降低失忆风险
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维生素B不可能会降低失忆风险
诸平
据MedicalXpress网站2014年11月12日报道，荷兰瓦赫宁根大学（Wageningen University）的研究人员研究发现，服用维生素B不可能降低失忆风险。这一发现是根据2014年11月12日, 美国神经病学学会（American Academy of Neurology）主办的一种在线医学杂志——《神经学》（Neurology）发表的一项最新研究得出的结论。这项研究是迄今为止最大的一次测试长期服用补品对思维和记忆能力的影响，测试结果出乎人们的预料，发现服用维生素B12和叶酸补充剂不可能会降低失忆风险。
此项研究涉及到血液中同型半胱氨酸水平高的人群, 同型半胱氨酸是一种氨基酸。高水平的同型半胱氨酸与记忆丧失（memory loss）和阿尔茨海默氏症（Alzheimer's disease）有关。荷兰瓦赫宁根大学Rosalie Dhonukshe-Rutten博士，也是此项研究的作者之一，他认为，“既然可以用叶酸（folic acid）和维生素B12补充剂来降低同型半胱氨酸水平, 也希望一直服用这些维生素的人可以减少记忆丧失和患阿尔茨海默氏症的风险。”
早期的观察性研究显示，服用叶酸和维生素B12可能会对思维和记忆能力（memory skills ）有一些好处,但随后的结果随机性太大、对照试验难以令人信服。对于此研究而言,涉及到平均年龄为74岁的人员有2919人,连续两年每天都服用叶酸400μg和维生素B12500μg的药片或安慰剂。在试验开始和结束时分别对受试者的记忆和思维能力进行了测试研究，所有的参与者都是血液中含有高水平的同型半胱氨酸的患者。
Rosalie Dhonukshe-Rutten博士说：“虽然服用更多的维生素B的一组比服用安慰剂的一组受试者的同型半胱氨酸水平降低了，但不幸的是两组受试者在思考和记忆测试中的得分没有差别。”此项研究得到荷兰的多家机构的资助，如荷兰卫生研究与发展组织（Netherlands Organization for Health Research and Development）、荷兰奶业协会（Dutch Dairy Association）、MCO健康（MCO Health）,荷兰健康老化财团（NetherlandsConsortium Healthy Aging）；荷兰经济事务、农业及创新部（Dutch Ministry of Economic Affairs, Agriculture and Innovation）,瓦赫宁根大学（Wageningen University）、VU大学医学中心和伊拉斯谟医学中心（VU University Medical Center and Erasmus Medical Center）等。除了上述研究结果，之前也有类似报道，如“服用维生素B不能预防阿尔茨海默氏症（Taking B vitamins won't prevent Alzheimer's disease）
论文摘要如下：
ABSTRACT
Objective: We investigated the effects of 2-year folic acid and vitamin B12 supplementation on cognitive performance in elderly people with elevated homocysteine (Hcy) levels.
Methods: This multicenter, double-blind, randomized, placebo-controlled trial included 2,919 elderly participants (65 years and older) with Hcy levels between 12 and 50 μmol/L. Participants received daily either a tablet with 400 μg folic acid and 500 μg vitamin B12 (B-vitamin group) or a placebo tablet. Both tablets contained 15 μg vitamin D3. Data were available for global cognitive functioning assessed by Mini-Mental State Examination (n = 2,556), episodic memory (n = 2,467), attention and working memory (n = 759), information processing speed (n = 731), and executive function (n = 721).
Results: Mean age was 74.1 (SD 6.5) years. Hcy concentrations decreased 5.0 (95% confidence interval −5.3 to −4.7) μmol/L in the B-vitamin group and 1.3 (−1.6 to −0.9) μmol/L in the placebo group. Cognitive domain scores did not differ over time between the 2 groups, as determined by analysis of covariance. Mini-Mental State Examination score decreased with 0.1 (−0.2 to 0.0) in the B-vitamin group and 0.3 (−0.4 to −0.2) in the placebo group (p = 0.05), as determined by an independent t test.
Conclusions: Two-year folic acid and vitamin B12 supplementation did not beneficially affect performance on 4 cognitive domains in elderly people with elevated Hcy levels. It may slightly slow the rate of decline of global cognition, but the reported small difference may be attributable to chance.
Classification of evidence: This study provides Class I evidence that 2-year supplementation with folic acid and vitamin B12 in hyperhomocysteinemic elderly people does not affect cognitive performance.
更多信息请浏览：http://www.neurology.org/content/early/2014/11/12/WNL.0000000000001050.short?rss=1
https://wap.sciencenet.cn/blog-212210-843250.html
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