Kiwis and apples are both celebrated for promoting gastrointestinal wellness, but which fruit truly stands out? As it turns out, kiwi may have an edge when it comes to digestion (the process of breaking down food), while the two offer similar benefits for overall gut health.
According to gut health dietitian and California State University Long Beach lecturer Amanda Sauceda, MS, RDN, what “makes kiwis stand out for digestion is how helpful they’ve been found to be for constipation.”
She pointed to two 2022 studies showing that after four weeks, people with functional constipation or constipation-dominant irritable bowel syndrome who ate two kiwis per day experienced less constipation—and in one of the studies, even greater improvement than those taking a fiber supplement.
Apples, on the other hand, certainly aren’t a bad choice for digestion. But apples’ primary digestive benefit is “in regulating stool consistency, rather than specifically accelerating or improving bowel movement frequency,” explained Minneapolis-based Oswald Digestive Clinic lead clinician Marcie Vaske, MS, LN, CNS.
Kiwi’s ability to ease constipation likely comes from its unique comination of nutrients—actinidin, a naturally occurring enzyme that breaks down proteins, and both soluble and insoluble fiber, explained Monica Amburn, MS, RDN, LDN, senior director of food and nutrition at the International Food Information Council.
“Kiwi fiber has a higher water retention and swelling capacity than apple or even wheat bran fiber,” Vaske added. “This means it can improve stool bulk and consistency more effectively, which is helpful if one struggles with constipation.”
Apples are high in fiber too—a serving contains just slightly less than the 4 grams found in kiwis—but the type is less balanced. The main fiber, pectin, is a soluble form that primarily helps soften stool, Vaske noted.
It’s also worth noting that, unlike kiwi, most of the digestion-supporting nutrients in apples are found in the peel, Vaske added—which many people don’t eat.
What’s more, apples could actually cause tummy troubles for some people due to their natural FODMAP content, Amburn said. “For these individuals, swapping to a low-FODMAP fruit such as kiwi is a great alternative,” she told Health.
When it comes to gut health—the overall well-being of the digestive tract, supported by the trillions of microbes that live there—kiwis and apples may actually be tied. “They both contain beneficial fibers to support a healthy microbiome,” Vaske said.
However, Sauceda noted that apples may have a slight advantage because their skin contains pectin, a fiber known for “feeding” healthy gut bacteria. “This also increases compounds called short-chain fatty acids, which help maintain the gut barrier,” she said.
Apples’ and kiwis’ gut-friendly antioxidants are neck-and-neck as well, with each containing “superior antioxidants,” Vaske said. These compounds help keep inflammation in the gut to a minimum and protect the integrity of the gut lining.
Looking to add more kiwis and apples to your meals and snacks? Doing so would be a good thing, according to Amburn.
“Apples and kiwis are fantastic fruits that both contain a mix of soluble and insoluble fibers, both of which are essential to a healthy gut microbiome and overall digestive function,” she said.
Vaske said the optimal daily portion for digestive benefits is one apple or two kiwis. Try any of these tasty, colorful suggestions:
- Add sliced apples or kiwi to oatmeal, yogurt, granola, or chia pudding.
- Toss together an all-green salad of leafy greens, apples, kiwis, celery, and a green goddess dressing.
- Make apple “bagels” by coring the fruit, slicing it horizontally, and topping with your favorite nut or seed butter, yogurt, or spice blend.
- Blend chopped kiwi into a smoothie or protein shake.
- Make skin-on stewed apples as an accompaniment to savory dishes like pork chops or grilled chicken.
- Mix diced kiwi or apple into a fruit salsa and serve with tortilla chips.