INTRODUCTION Improvement of cognitive function may be desirable for healthy individuals and clinically beneficial for those with cognitive impairment such as from Alzheimer's disease (AD) or mild cognitive impairment (MCI). The aim of this systematic review is to investigate the cognitive effects of oral saffron intake, in patients with MCI/AD and/or in non-demented individuals, by following the PRISMA guidelines. METHODS We performed a literature search on MedLine, Cochrane library, and ClinicalTrials.gov to identify randomized controlled trials (RCTs) investigating the effects of oral saffron administration in patients with MCI/AD and/or in non-demented individuals. RESULTS Five studies (enrolling 325 individuals) met our inclusion criteria. Four studies included patients with MCI/AD, and one study included cognitively normal individuals. Saffron was well-tolerated in all groups. Regarding cognitively impaired patients, scores on Alzheimer's Disease Assessment Scale-cognitive subscale or Mini mental state examination were significantly better when saffron was compared with placebo and did not differ significantly when saffron was compared with donepezil or memantine. Saffron effects on functional status were similar with its effects on cognition. CONCLUSIONS Saffron was shown to be equally effective to common symptomatic drugs for MCI/AD and resulted in no difference in the incidence of side effects, when compared with placebo or drugs. The promising results should be seen cautiously, since the evidence was derived from studies with potentially high risk of bias (ROB). RCTs with larger sample sizes and low ROB are required to definitively assess the potential role of saffron as an MCI/AD treatment.

中文翻译：

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藏红花（Crocus sativus L.）对认知功能的影响。对随机对照试验的系统评价。

引言 认知功能的改善可能对健康个体有益，对患有认知障碍（例如阿尔茨海默病 (AD) 或轻度认知障碍 (MCI)）的患者具有临床益处。本系统评价的目的是遵循 PRISMA 指南，研究口服藏红花摄入对 MCI/AD 患者和/或非痴呆症患者的认知影响。方法 我们在 MedLine、Cochrane 图书馆和 ClinicalTrials.gov 上进行了文献检索，以确定随机对照试验 (RCT)，这些试验研究了口服藏红花给药对 MCI/AD 患者和/或非痴呆个体的影响。结果 五项研究（招募 325 人）符合我们的纳入标准。四项研究包括 MCI/AD 患者，一项研究包括认知正常的个体。藏红花在所有组中都具有良好的耐受性。对于认知障碍患者，当藏红花与安慰剂相比时，阿尔茨海默病评估量表-认知分量表或迷你精神状态检查的得分明显更好，而当藏红花与多奈哌齐或美金刚相比时，没有显着差异。藏红花对功能状态的影响与其对认知的影响相似。结论 与安慰剂或药物相比，藏红花与 MCI/AD 的常见对症药物同样有效，并且副作用发生率没有差异。应该谨慎看待有希望的结果，因为证据来自具有潜在高偏倚风险 (ROB) 的研究。