Xu Manru, Zhu Yue, Chen Jinxin, Li Jie, Qin Jingbo, Fan Yiran, Ren Pan, Hu Huixue, Wu Wenbin
Department of Geriatrics, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China.
J Evid Based Med. 2024 Mar;17(1):134-144. doi: 10.1111/jebm.12588. Epub 2024 Mar 11.
With the increasing number of patients with cognitive impairment, nonpharmacological ways to delay cognitive impairment have attracted people's attention, such as lifestyle changes and nutritional supplementation. Folic acid supplementation appears to be a promising treatment option. However, it remains controversial whether folic acid supplementation is effective in delaying adult's cognitive impairment. Therefore, we conducted a meta-analysis to analyze the effects of folic acid supplementation on different cognitive impairments.
We systematically searched PubMed, Web of Science, EMbase, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure (CNKI), WanFang and VIP databases for randomized controlled trials on January 22, 2024. The included population comprised those diagnosed with cognitive impairment. We included trials that compared folic acid treatment with placebo, other dosing regimens, or other intervention controls. Conducting quality evaluation of included studies according to the Cochrane Risk of Bias tool. Statistical analyses were performed using Review Manager software.
Twenty-two trials, including 3604 participants, met inclusion criteria. Compared with controls, the cognitive function of Alzheimer's disease (AD) patients showed improvement with folic acid supplementation: supplementation with < 3 mg (standardized mean differences (SMD) = 0.15, 95% confidence interval (CI) -0.10 to 0.41), and supplementing with ≥ 3 mg folic acid could improve cognitive function in AD patients (SMD = 1.03, 95% CI 0.18 to 1.88). Additionally, it reduced homocysteine (HCY) levels (mean differences (MD) = -4.74, 95% CI -8.08 to -1.39). In mild cognitive impairment (MCI) patients, cognitive function improved with folic acid supplementation: supplementation with > 400 μg (SMD = 0.38, 95% CI 0.13 to 0.63), and supplementation with ≤ 400 μg (SMD = 1.10, 95% CI 0.88 to 1.31). It also reduced HCY levels at intervention ≤ 6 months (MD = -3.93, 95% CI -5.05 to -2.82) and intervention > 6 months (MD = -4.38, 95% CI -5.15 to -3.61). However, supplementing with folic acid did not improve cognitive function in vascular cognitive impairment (VCI) patients, with folic acid supplements < 3 mg (SMD = -0.07, 95% CI -0.23 to -0.08), folic acid supplements ≥ 3 mg (SMD = 0.46, 95% CI -0.57 to 1.49), however, it reduced HCY levels at intervention > 6 months (MD = -5.91, 95% CI -7.13 to -4.69) and intervention ≤ 6 months (MD = -11.15, 95% CI -12.35 to -9.95).
Supplement folic acid is beneficial to the cognitive profile of patients with MCI, supplementation with ≥ 3 mg folic acid can improve cognitive function in AD patients.
随着认知障碍患者数量的增加，延缓认知障碍的非药物方法引起了人们的关注，如生活方式改变和营养补充。补充叶酸似乎是一种有前景的治疗选择。然而，补充叶酸是否能有效延缓成年人的认知障碍仍存在争议。因此，我们进行了一项荟萃分析，以分析补充叶酸对不同认知障碍的影响。
我们于2024年1月22日系统检索了PubMed、Web of Science、EMbase、Cochrane对照试验中央注册库、中国知网（CNKI）、万方和维普数据库，以查找关于随机对照试验的文献。纳入人群包括那些被诊断为认知障碍的患者。我们纳入了比较叶酸治疗与安慰剂、其他给药方案或其他干预对照的试验。根据Cochrane偏倚风险工具对纳入研究进行质量评估。使用Review Manager软件进行统计分析。
22项试验，共3604名参与者，符合纳入标准。与对照组相比，补充叶酸后阿尔茨海默病（AD）患者的认知功能有所改善：补充<3mg叶酸（标准化均数差（SMD）=0.15，95%置信区间（CI）-0.10至0.41），补充≥3mg叶酸可改善AD患者的认知功能（SMD=1.03，95%CI 0.18至1.88）。此外，它降低了同型半胱氨酸（HCY）水平（均数差（MD）=-4.74，95%CI -8.08至-1.39）。在轻度认知障碍（MCI）患者中，补充叶酸后认知功能得到改善：补充>400μg叶酸（SMD=0.38，95%CI 0.13至0.63），补充≤400μg叶酸（SMD=1.10，95%CI 0.88至1.31）。在干预≤6个月（MD=-3.93，95%CI -5.05至-2.82）和干预>6个月（MD=-4.38，95%CI -5.15至-3.61）时，它也降低了HCY水平。然而，补充叶酸并未改善血管性认知障碍（VCI）患者的认知功能，补充<3mg叶酸（SMD=-0.07，95%CI -0.23至-0.08），补充≥3mg叶酸（SMD=0.46，95%CI -0.57至1.49），但在干预>6个月（MD=-5.91，95%CI -7.13至-4.69）和干预≤6个月（MD=-11.15，95%CI -12.35至-9.95）时，它降低了HCY水平。
补充叶酸对MCI患者的认知状况有益，补充≥3mg叶酸可改善AD患者的认知功能。
