Kiwifruit and Digestive Health
Professor Richard Gearry
University of Otago, New Zealand
Digestive discomfort, including constipation is a common condition throughout the world and is reported to affect around 15% of adults in western countries1. Gastrointestinal discomfort and bowel habit are two target areas for potential health claims for foods identified by EFSA2.
Green kiwifruit (Actinidia deliciosa var. Hayward) are often used as a natural food to assist with the relief of constipation and potential relief of gastrointestinal symptoms3-5. The randomised, controlled cross-over clinical trial presented here was carried out in New Zealand, but is currently also in progress in two other sites around the world – Italy and Japan – using the same protocol.
Three cohorts of participants were recruited: A healthy group (H); a functionally constipated group (FC); and a group with irritable bowel syndrome constipated type (IBS-C) assigned according to Rome III criteria6,7. The cross-over design will be completed using the kiwifruit intervention (2 green kiwifruit per day [Actinidia deliciosa var. Hayward]), compared to a positive control intervention of psyllium (7.5 g of psyllium per day providing 6 g fibre)8. All participants were free living and required to maintain their normal dietary and lifestyle habits for the duration of the trial.
The primary outcome measure, quantification of complete spontaneous bowel movement [CBSM], is currently being analysed and results will be presented at the 1st International Symposium on Kiwifruit and Health for the first time.
The secondary outcome measures included additional stool frequency measures, validated questionnaires on digestive symptoms and comfort using the Gastrointestinal Symptom Rating Scale [GSRS]. The IBS-QOL questionnaire together with objective measures of gastrointestinal transit times using Smart Pills are not presented here.
This goal of this study was to demonstrate the efficacy of kiwifruit as a food intervention for the relief of constipation and associated symptoms in functionally constipated adults, and those with IBS-C.
1. Wald A et al. The burden of constipation on quality of life: results of a multinational survey. Aliment Pharmacol Ther. 2007;26(2):227-36. // 2. EFSA Panel on Dietetic Products Nutrition and Allergies (NDA), Guidance on the scientific requirements for health claims related to gut and immune function. EFSA Journal. 2011;9(4):1984. // 3. Chan AO et al. Increasing dietary fiber intake in terms of kiwifruit improves constipation in Chinese patients. World J Gastroenterol. 2007;13(35):4771-5. // 4. Chang CC et al. Kiwifruit improves bowel function in patients with irritable bowel syndrome with constipation. Asia Pac J Clin Nutr. 2010;19(4):451-7. // 5. Rush EC et al. Kiwifruit promotes laxation in the elderly. Asia Pac J Clin Nutr. 2002;11(2):164-8. // 6. Longstreth GF et al. Functional bowel disorders. Gastroenterology. 2006;130(5):1480-91. // 7. Rome Foundation Rome III Disorders and Criteria. http://www.romecriteria.org/criteria (accessed 16 February). // 8. Attaluri A et al. Randomised clinical trial: dried plums (prunes) vs. psyllium for constipation. Aliment Pharmacol Ther. 2011;33(7):822-8.