Encapsulated green kiwifruit extract: a randomised controlled trial investigating alleviation of constipation in otherwise healthy adults

Asia Pac J Clin Nutr. 2015;24(3):421-9. doi: 10.6133/apjcn.2015.24.3.15.


Objectives: Previous clinical trials have shown bowel function is improved through consumption of whole kiwifruit (Actinidia deliciosa). This study investigated whether encapsulated kiwifruit extract (1 g/day) could alleviate constipation in otherwise healthy adults.

Methods: Forty adults with confirmed constipation entered this trial, of which 32 completed with >80% compliance. Two capsules were self-administered morning and evening for 2 periods, each of 3 weeks duration, separated by a 3+ week washout in a double blind, randomised, placebo controlled crossover. Inclusion criteria included constipation with <=3 bowel movements (BM) per week. Daily records of defecation frequency and stool characteristics were obtained throughout treatment, as well as a measurement of gastrointestinal symptoms rating scale (GSRS) and quality of life (QoL) before and after each intervention arm.

Results: There was no difference in total BM over 3 weeks (p>0.05) or mean BM during each of weeks 1, 2 and 3 (p>0.05) between the kiwifruit extract and placebo when assessed from a faecal diary. There was also no detectable difference in defecation related scores of BM ease of defecation, volume, consistency or BM type assessed using Bristol stool chart scores. Nor was there a significant change in GSRS or QoL between pre and post treatment measures, when compared to placebo (p>0.05).

Conclusions: This trial showed that improvement in bowel function or comfort was not achieved through supplementation with 1 g/day freeze dried kiwifruit extract. Efficacy from prior kiwifruit powder and whole fruit trials indicate that investigating higher doses of encapsulated kiwifruit extract may be worthwhile.

目的:以前的临床试验显示食用整个猕猴桃能够改善肠道功能。本研究探讨 猕猴桃提取物胶囊(1 g/天)是否能够缓解健康成人便秘。方法:四十个便秘 的成年人进入该试验,其中32 人完成了试验,达标率为80%。这是一个双 盲、随机、安慰剂对照的交叉试验,每期3 周,每日2 粒胶囊早晚各服一粒, 两期间是一个3 周的洗脱期。纳入标准为便秘,即每周排便<=3 次。在整个治 疗期间,每天记录排便频率和粪便特征,每次干预前后用消化道症状评定量表 (GSRS)和生活质量(QoL)问卷评估胃肠道症状。结果:当通过粪便日记 评估时,没有发现猕猴桃提取物和安慰剂之间在3 周干预期总的大便次数 (p>0.05)或第1、第2 和第3 周两组之间平均大便次数有差异(p>0.05)。 也没有检测到用布里斯托尔大便图表测得的用于评估排便的容易性、大便的体 积、排便的连贯性或大便的类型的得分之间有差异。与安慰剂相比,也没有发 现干预前后GSRS 或QoL 有显著变化(p>0.05)。结论:本实验表明,通过 每天补充1 g 冷冻干燥的猕猴桃提取物不能改善肠道功能或舒适度。之前的猕 猴桃粉和全果的实验疗效表明:探讨高剂量的猕猴桃提取物胶囊可能值得一 试。.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actinidia*
  • Adult
  • Capsules
  • Constipation / drug therapy*
  • Cross-Over Studies
  • Dietary Supplements*
  • Double-Blind Method
  • Female
  • Fruit*
  • Humans
  • Male
  • Middle Aged
  • Plant Extracts / pharmacology*
  • Treatment Outcome
  • Young Adult


  • Capsules
  • Plant Extracts