Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK.
Department of Medicine, School of Clinical Sciences, Monash University, Australia.
Nutr Rev. 2024 Oct 1;82(10):1372-1385. doi: 10.1093/nutrit/nuad135.
Histidine-containing dipeptides (carnosine, anserine, beta-alanine and others) are found in human muscle tissue and other organs like the brain. Data in rodents and humans indicate that administration of exogenous carnosine improved cognitive performance. However, RCTs results vary.
To perform a systematic review and meta-analysis of randomized controlled trials (RCTs) of histidine-containing dipeptide (HCD) supplementation on cognitive performance in humans to assess its utility as a cognitive stabiliser.
OVID Medline, Medline, EBM Reviews, Embase, and Cumulative Index to Nursing and Allied Health Literature databases from 1/1/1965 to 1/6/2022 for all RCT of HCDs were searched.
2653 abstracts were screened, identifying 94 full-text articles which were assessed for eligibility. Ten articles reporting the use of HCD supplementation were meta-analysed.
The random effects model has been applied using the DerSimonian-Laird method. HCD treatment significantly increased performance on Wechsler Memory Scale (WMS) -2 Delayed recall (Weighted mean difference (WMD) (95% CI (CI)) = 1.5 (0.6, 2.5), P < .01). Treatment with HCDs had no effect on Alzheimer's Disease Assessment Scale-Cognitive (WMD (95% CI) = -0.2 (-1.1, 0.7), P = .65, I2 = 0%), Mini-Mental State Examination (WMD (95% CI) = 0.7 (-0.2, 1.5), P = .14, I2 = 42%), The Wechsler Adult Intelligence Scale (WAIS) Digit span Backward (WMD (95% CI) = 0.1 (-0.3, 0.5), P = .51, I2 = 0%), WAIS digit span Forward (WMD (95% CI) = 0.0 (-0.3, 0.4), P = .85, I2 = 33%) and the WMS-1 Immediate recall (WMD (95% CI) = .7 (-.2, 1.5), P = .11, I2 = 0%). The effect on delayed recall remained in subgroup meta-analysis performed on studies of patients without mild cognitive impairment (MCI), and in those without MCI where average age in the study was above 65.
HCD, supplementation improved scores on the Delayed recall examination, a neuropsychological test affected early in Alzheimer's disease. Further studies are needed in people with early cognitive impairment with longer follow-up duration and standardization of carnosine doses to delineate the true effect.
PROSPERO registration no. CRD42017075354.
组氨酸二肽（肌肽、鹅肌肽、β-丙氨酸等）存在于人体肌肉组织和大脑等其他器官中。啮齿动物和人类的数据表明，外源性肌肽的给药改善了认知表现。然而，RCT 结果存在差异。
对组氨酸二肽（HCD）补充剂对人类认知表现的随机对照试验（RCT）进行系统评价和荟萃分析，以评估其作为认知稳定剂的效用。
从 1965 年 1 月 1 日至 2022 年 1 月 6 日，在 OVID Medline、Medline、EBM Reviews、Embase 和 Cumulative Index to Nursing and Allied Health Literature 数据库中搜索了所有关于 HCD 的 RCT 的文献。
筛选了 2653 篇摘要，确定了 94 篇全文文章进行资格评估。对 10 篇报告使用 HCD 补充剂的文章进行了荟萃分析。
采用 DerSimonian-Laird 方法应用随机效应模型。HCD 治疗显著提高了韦氏记忆量表（WMS）-2 延迟回忆的表现（加权均数差（WMD）（95%置信区间（CI））= 1.5（0.6, 2.5），P<0.01）。HCD 治疗对阿尔茨海默病评估量表认知（WMD（95%CI）= -0.2（-1.1, 0.7），P=0.65，I2=0%）、简易精神状态检查（WMD（95%CI）= 0.7（-0.2, 1.5），P=0.14，I2=42%）、韦氏成人智力量表（WAIS）数字跨度回溯（WMD（95%CI）= 0.1（-0.3, 0.5），P=0.51，I2=0%）、WAIS 数字跨度前向（WMD（95%CI）= 0.0（-0.3, 0.4），P=0.85，I2=33%）和 WMS-1 即时回忆（WMD（95%CI）= 0.7（-0.2, 1.5），P=0.11，I2=0%）无影响。在对无轻度认知障碍（MCI）的患者进行的亚组荟萃分析和对研究中平均年龄大于 65 岁的无 MCI 的患者进行的亚组荟萃分析中，延迟回忆的效果仍然存在。需要在有早期认知障碍的人群中进行进一步的研究，以延长随访时间并标准化肌肽剂量，以明确其真实效果。
PROSPERO 注册号：CRD42017075354。
