Does Eating Two Kiwifruit a Day Actually Fix Constipation Better Than Prunes?

If you have spent any time on the internet looking for a food that keeps things moving, you have met the prune. It works. But prunes are sweet, sorbitol-heavy, and a lot of people find two servings a day rough on the gut. The more interesting recent contender is green kiwifruit, and there is now a decent head-to-head trial worth knowing about.

A 2023 randomized crossover study published in The American Journal of Gastroenterology (Chey and colleagues) tested green kiwifruit against prunes and psyllium in adults with functional constipation and IBS-constipation across three countries (see [1]). Two kiwifruit a day, four weeks per treatment. Kiwifruit produced a clinically meaningful increase in complete spontaneous bowel movements, and it did it with fewer complaints about gas and bloating than the other two. Prunes and psyllium worked too, but people tolerated the kiwifruit better, which matters because the best fiber intervention is the one you will actually keep eating. This lines up with earlier work from the same research group in Asian populations showing kiwifruit improved transit and stool frequency (see [2]).

The likely mechanism is not just fiber. Green kiwifruit contains an enzyme called actinidin plus a fiber that holds water well, so it softens stool and adds bulk without the heavy sorbitol load that makes prunes gassy for some people. Roughly two kiwifruit gets you around 6 grams of fiber, which is real but not enormous, so the effect is probably a combination of the fiber, the water-holding capacity, and the enzyme working together. Translation: it is doing more than its fiber number alone would predict.

Here is the practical read. If prunes work for you and you like them, keep going, this is not a reason to switch. But if prunes leave you bloated, two green kiwifruit a day is a genuinely evidence-backed swap that most people tolerate better, and it is a pleasant thing to eat rather than a chore. Give any change a couple of weeks before you judge it, because gut habits are a trend, not a single morning. If you log your meals in /nutrition, tagging the days you add kiwifruit makes it easy to see whether your own pattern actually shifts.

This is general information, not medical advice — talk to a qualified clinician about your own situation.