Kiwifruit can increase the frequency of bowel movements for people with constipation, according to researchers in New Zealand.
“In addition to improved measures of constipation status, there was a significant improvement in stool consistency, reduction in constipation, indigestion/reflux, and abdominal pain resulting in an improved overall level of GI comfort,” write Richard Gearry, MD, PhD, of the University of Otago, New Zealand, and colleagues.
Gearry and colleagues describe their international multicenter controlled trial of kiwifruit as a constipation treatment in The American Journal of Gastroenterology.
Although constipation is common, previous researchers have reported a high rate of dissatisfaction with pharmaceutical treatments.
Fiber found in kiwifruit cell walls swells and holds water, which can soften stools and increase stool frequency. Other components of kiwifruit, such as raphides, may alter mucin production, leading to improved laxation.
The researchers set out to test the benefits of the fruit in a more rigorous trial. They recruited adults in New Zealand, Italy, and Japan who had either functional constipation or constipation-predominant irritable bowel syndrome (IBS-C), as well as healthy people as controls. The primary difference between functional constipation and IBS-C is that people with IBS-C experience abdominal pain along with constipation, they write.
Between June 12, 2014, and June 17, 2017, 184 participants were enrolled. Participants included 136 women and 48 men, a proportion consistent with the gender prevalence of constipation. The mean age was 30.5 years in Japan, 36.9 years in Italy, and 44.8 years in New Zealand, and the mean body mass index was 20.6 in Japan, 23.0 in Italy, and 25.4 in New Zealand.
For 2 weeks following recruitment, the participants became accustomed to recording their bowel movements with respect to frequency, completeness, spontaneity, stool form, laxative use, and degree of straining.
Participants were then randomly assigned to consume either two ripe green kiwifruit (Actinidia chinensis var. deliciosa “Hayward”) without the skins, or 7.5 g of psyllium per day for 4 weeks. Psyllium is considered a first-line treatment for both the constipation conditions with which participants were diagnosed. The fiber content of psyllium is similar to that of kiwifruit.
After 4 weeks, treatments were stopped for 4 weeks as a washout period, after which patients were switched to the other treatment for another 4 weeks.
The researchers provided them with two bisacodyl (5-g suppositories) as a pharmacologic rescue therapy.
Overall, 169 participants completed the study, and compliance with diary completion was over 80%.