Jepson Ruth G, Williams Gabrielle, Craig Jonathan C
Department of Nursing and Midwifery, University of Stirling, Stirling, UK.
Cochrane Database Syst Rev. 2012 Oct 17;10(10):CD001321. doi: 10.1002/14651858.CD001321.pub5.
Cranberries have been used widely for several decades for the prevention and treatment of urinary tract infections (UTIs). This is the third update of our review first published in 1998 and updated in 2004 and 2008.
To assess the effectiveness of cranberry products in preventing UTIs in susceptible populations.
We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL in The Cochrane Library) and the Internet. We contacted companies involved with the promotion and distribution of cranberry preparations and checked reference lists of review articles and relevant studies.Date of search: July 2012
All randomised controlled trials (RCTs) or quasi-RCTs of cranberry products for the prevention of UTIs.
Two authors independently assessed and extracted data. Information was collected on methods, participants, interventions and outcomes (incidence of symptomatic UTIs, positive culture results, side effects, adherence to therapy). Risk ratios (RR) were calculated where appropriate, otherwise a narrative synthesis was undertaken. Quality was assessed using the Cochrane risk of bias assessment tool.
This updated review includes a total of 24 studies (six cross-over studies, 11 parallel group studies with two arms; five with three arms, and two studies with a factorial design) with a total of 4473 participants. Ten studies were included in the 2008 update, and 14 studies have been added to this update. Thirteen studies (2380 participants) evaluated only cranberry juice/concentrate; nine studies (1032 participants) evaluated only cranberry tablets/capsules; one study compared cranberry juice and tablets; and one study compared cranberry capsules and tablets. The comparison/control arms were placebo, no treatment, water, methenamine hippurate, antibiotics, or lactobacillus. Eleven studies were not included in the meta-analyses because either the design was a cross-over study and data were not reported separately for the first phase, or there was a lack of relevant data. Data included in the meta-analyses showed that, compared with placebo, water or not treatment, cranberry products did not significantly reduce the occurrence of symptomatic UTI overall (RR 0.86, 95% CI 0.71 to 1.04) or for any the subgroups: women with recurrent UTIs (RR 0.74, 95% CI 0.42 to 1.31); older people (RR 0.75, 95% CI 0.39 to 1.44); pregnant women (RR 1.04, 95% CI 0.97 to 1.17); children with recurrent UTI (RR 0.48, 95% CI 0.19 to 1.22); cancer patients (RR 1.15 95% CI 0.75 to 1.77); or people with neuropathic bladder or spinal injury (RR 0.95, 95% CI: 0.75 to 1.20). Overall heterogeneity was moderate (I² = 55%). The effectiveness of cranberry was not significantly different to antibiotics for women (RR 1.31, 95% CI 0.85, 2.02) and children (RR 0.69 95% CI 0.32 to 1.51). There was no significant difference between gastrointestinal adverse effects from cranberry product compared to those of placebo/no treatment (RR 0.83, 95% CI 0.31 to 2.27). Many studies reported low compliance and high withdrawal/dropout problems which they attributed to palatability/acceptability of the products, primarily the cranberry juice. Most studies of other cranberry products (tablets and capsules) did not report how much of the 'active' ingredient the product contained, and therefore the products may not have had enough potency to be effective.
AUTHORS' CONCLUSIONS: Prior to the current update it appeared there was some evidence that cranberry juice may decrease the number of symptomatic UTIs over a 12 month period, particularly for women with recurrent UTIs. The addition of 14 further studies suggests that cranberry juice is less effective than previously indicated. Although some of small studies demonstrated a small benefit for women with recurrent UTIs, there were no statistically significant differences when the results of a much larger study were included. Cranberry products were not significantly different to antibiotics for preventing UTIs in three small studies. Given the large number of dropouts/withdrawals from studies (mainly attributed to the acceptability of consuming cranberry products particularly juice, over long periods), and the evidence that the benefit for preventing UTI is small, cranberry juice cannot currently be recommended for the prevention of UTIs. Other preparations (such as powders) need to be quantified using standardised methods to ensure the potency, and contain enough of the 'active' ingredient, before being evaluated in clinical studies or recommended for use.
几十年来，蔓越莓已被广泛用于预防和治疗尿路感染（UTIs）。这是我们首次发表于1998年、并于2004年和2008年更新的综述的第三次更新。
评估蔓越莓产品在易感人群中预防UTIs的有效性。
我们检索了MEDLINE、EMBASE、Cochrane对照试验中心注册库（Cochrane图书馆中的CENTRAL）和互联网。我们联系了参与蔓越莓制剂推广和分销的公司，并查阅了综述文章和相关研究的参考文献列表。检索日期：2012年7月
所有关于蔓越莓产品预防UTIs的随机对照试验（RCTs）或半随机对照试验。
两位作者独立评估并提取数据。收集了关于方法、参与者、干预措施和结果（有症状UTIs的发生率、阳性培养结果、副作用、治疗依从性）的信息。在适当情况下计算风险比（RR），否则进行叙述性综述。使用Cochrane偏倚风险评估工具评估质量。
本次更新的综述共纳入24项研究（6项交叉研究、11项双臂平行组研究；5项三臂研究和2项析因设计研究），共4473名参与者。2008年更新纳入了10项研究，本次更新增加了14项研究。13项研究（2380名参与者）仅评估了蔓越莓汁/浓缩汁；9项研究（1032名参与者）仅评估了蔓越莓片/胶囊；1项研究比较了蔓越莓汁和片剂；1项研究比较了蔓越莓胶囊和片剂。对照/对照组为安慰剂、不治疗、水、马尿酸乌洛托品、抗生素或乳酸菌。11项研究未纳入荟萃分析，原因要么是设计为交叉研究且未单独报告第一阶段的数据，要么是缺乏相关数据。纳入荟萃分析的数据显示，与安慰剂、水或不治疗相比，蔓越莓产品总体上并未显著降低有症状UTI的发生率（RR 0.86，95%CI 0.71至1.04），在任何亚组中均未显著降低：复发性UTIs女性（RR 0.74，95%CI 0.42至1.31）；老年人（RR 0.75，95%CI 0.39至1.44）；孕妇（RR 1.04，95%CI 0.97至1.17）；复发性UTI儿童（RR 0.48，95%CI 0.19至1.22）；癌症患者（RR 1.15，95%CI 0.75至1.77）；或神经性膀胱或脊髓损伤患者（RR 0.95，95%CI：0.75至1.20）。总体异质性为中度（I² = 55%）。蔓越莓对女性（RR 1.31，95%CI 0.85，2.02）和儿童（RR 0.69，95%CI 0.32至1.51）的有效性与抗生素无显著差异。与安慰剂/不治疗相比，蔓越莓产品的胃肠道不良反应无显著差异（RR 0.83，95%CI 0.31至2.27）。许多研究报告了低依从性和高退出/失访问题，他们将其归因于产品的适口性/可接受性，主要是蔓越莓汁。大多数其他蔓越莓产品（片剂和胶囊）的研究未报告产品中含有多少“活性”成分，因此这些产品可能没有足够的效力来发挥作用。
在本次更新之前，似乎有一些证据表明蔓越莓汁可能在为期12个月的时间内减少有症状UTIs的数量，特别是对于复发性UTIs女性。增加的14项研究表明蔓越莓汁的效果不如先前所示。尽管一些小型研究表明对复发性UTIs女性有小的益处，但纳入一项大得多的研究结果时并无统计学显著差异。在三项小型研究中，蔓越莓产品在预防UTIs方面与抗生素无显著差异。鉴于研究中有大量的退出/失访（主要归因于长期食用蔓越莓产品特别是果汁时的可接受性），以及预防UTI的益处较小的证据，目前不推荐使用蔓越莓汁预防UTIs。其他制剂（如粉剂）在临床研究中进行评估或推荐使用之前，需要使用标准化方法进行定量以确保效力，并含有足够的“活性”成分。
