BACKGROUND Folate and vitamin B12 are well-known as essential nutrients that play key roles in the normal functions of the brain. Inflammatory processes play at least some role in the pathology of AD. Effective nutritional intervention approaches for improving cognitive deficits that reduce the peripheral inflammatory cytokine levels have garnered special attention. OBJECTIVE The present study aimed to determine whether supplementation with folic acid and vitamin B12, alone and in combination improves cognitive performance via reducing levels of peripheral inflammatory cytokines. METHODS 240 participants with MCI were randomly assigned in equal proportion to four treatment groups: folic acid alone, vitamin B12 alone, folic acid plus vitamin B12 or control without treatment daily for 6 months. Cognition was measured with WAIS-RC. The levels of inflammatory cytokines were measured using ELISA. Changes in cognitive function or blood biomarkers were analyzed by repeatedmeasure analysis of variance or mixed-effects models. This trial has been registered with trial number ChiCTR-ROC-16008305. RESULTS Compared with control group, the folic acid plus vitamin B12 group had significantly greater improvements in serum folate, homocysteine, vitamin B12 and IL-6, TNF-α, MCP-1. The folic acid plus vitamin B12 supplementation significantly changed the Full Scale IQ (effect size d = 0.169; P = 0.024), verbal IQ (effect size d = 0.146; P = 0.033), Information (d = 0.172; P = 0.019) and Digit Span (d = 0.187; P = 0.009) scores. Post hoc Turkey tests found that folic acid and vitamin B12 supplementation was significantly more effective than folic acid alone for all endpoints. CONCLUSIONS The combination of oral folic acid plus vitamin B12 in MCI elderly for six months can significantly improve cognitive performance and reduce the levels of inflammatory cytokines in human peripheral blood. The combination of folic acid and vitamin B12 was significantly superior to either folic acid or vitamin B12 alone.

中文翻译：

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叶酸和维生素B12单独及组合对轻度认知障碍老年人认知功能和炎症因子的影响：单盲实验设计。

背景技术叶酸和维生素B12是众所周知的必需营养素，在大脑的正常功能中起关键作用。炎症过程至少在AD的病理中起一定作用。有效的营养干预措施可改善认知缺陷，减少周围炎症细胞因子水平，已引起特别关注。目的本研究旨在确定单独或联合添加叶酸和维生素B12是否可以通过降低外周炎症细胞因子水平来改善认知能力。方法将240名MCI参与者按等比例随机分为四个治疗组：仅叶酸，仅维生素B12，叶酸加维生素B12或对照组，每天治疗6个月。用WAIS-RC测量认知度。使用ELISA测量炎性细胞因子的水平。通过方差或混合效应模型的重复测量分析来分析认知功能或血液生物标志物的变化。该试验已注册，试验编号为ChiCTR-ROC-16008305。结果与对照组相比，叶酸加维生素B12组的血清叶酸，高半胱氨酸，维生素B12和IL-6，TNF-α，MCP-1的改善明显。叶酸和维生素B12的添加显着改变了全智商（影响大小d = 0.169; P = 0.024），口头智商（影响大小d = 0.146; P = 0.033），信息（d = 0.172; P = 0.019）和数字跨度（d = 0.187; P = 0.009）得分。土耳其的事后测试发现，在所有指标上，叶酸和维生素B12的补充比单独叶酸有效得多。结论口服叶酸加维生素B12在MCI老年人中使用六个月可以显着改善认知能力并降低人外周血中炎性细胞因子的水平。叶酸和维生素B12的组合明显优于单独的叶酸或维生素B12。