Improvement of functional constipation with kiwifruit intake in a Mediterranean patient population: An open, non-randomized pilot study

Introduction: Kiwifruit consumption has shown to improve functional constipation in healthy elderly population, according to studies in New Zealand and China. The aim of this study was to evaluate the effect of kiwifruit intake on functional constipation in a Mediterranean patient population characterized by its distinctive nutritional habits. Material and Methods: An open, non-controlled and non-randomized longitudinal study was conducted in 46 patients with constipation (Rome III criteria). Patients monitored for five weeks: weeks 1 and 2 no kiwifruit and weeks 3-5 three kiwifruit per day (Green kiwifruit, Actinidia deliciosa var Hayward). Bristol Scale, volume of stools, and ease of defecation was self- reported daily. The evolution of the categorical variables was tested using the Bhapkar test; functional data methodology was used for continuous variables, and Generalized Estimating Equation (GEE) models were adjusted. Results: The percentage of patients with ≥3 stools per week increased from 82.61% (95% CI: 69–91.2) at week 1 to 97.78% (95% CI: 87.4–99.9) at week 2 of kiwifruit intake, with 76.09% (95% CI: 61.9–86.2) responding during the first week. The reporting of stable ideal stools increased from 17.39% (95% CI: 8.8–31) at week 2 to 33.33% (95% CI: 21.3–48) at week 5. According to GEE models, the number of depositions increased significantly (p-values<0.001) in 0.398 daily units at week 1 the first week of intake, up to 0.593 daily units at week 5; significant improvements on facility in evacuation and volume of evacuation were found from the first week of intake (all p-values<0.001). Conclusions: The intake of three kiwifruits per day significantly improves the quality of evacuation (number of depositions, volume, consistency and ease) in a Mediterranean patient population suffering from functional constipation.