The kiwi fruit is a popular remedy suggested for those experiencing occasional digestive irregularity and is often used as a natural way to encourage bowel movements. Scientific investigation has explored the long-standing belief that kiwi fruit possesses properties that can effectively address issues like constipation.
Clinical Evidence Supporting Kiwi for Digestive Regularity
Kiwi fruit consumption has been shown in human studies to significantly improve bowel function. Research indicates that eating two green kiwis daily for a period of four weeks can increase the frequency of complete spontaneous bowel movements per week. This effect has been observed in healthy adults as well as individuals dealing with functional constipation or irritable bowel syndrome with constipation (IBS-C).
In comparative trials, kiwi fruit has demonstrated an ability to increase stool frequency and improve consistency, often with better tolerability than common fiber supplements like psyllium husk. Specifically, studies have shown that kiwi consumption leads to softer stools and a greater sense of complete evacuation. Furthermore, participants reported higher satisfaction rates with kiwi fruit compared to psyllium or prunes, largely because it resulted in fewer uncomfortable side effects like bloating and gas.
The Digestive Components of Kiwi
The positive effects of kiwi fruit are attributed to its unique combination of fiber, water, and a specific enzyme. A single kiwi provides fiber that consists of both insoluble and soluble types, which work together to facilitate gut transit. The insoluble fiber adds bulk to the stool, helping it move more quickly through the digestive tract and promoting regularity. The soluble fiber component absorbs water, creating a gel-like substance that softens the stool and contributes to its overall volume. Kiwi fruit also has a high water-holding capacity, which increases water retention in the colon, further contributing to softer and bulkier stools.
Beyond fiber, kiwi fruit contains the enzyme actinidin, a cysteine protease unique to the fruit. Actinidin assists in the digestion of proteins, breaking them down into smaller components in the stomach and small intestine. By enhancing protein digestion, actinidin may reduce digestive discomfort such as bloating and may also stimulate receptors in the colon, contributing to increased gut motility and a faster transit time.
Recommended Consumption and Safety Guidelines
For digestive benefits, the most frequently studied and recommended amount is the consumption of two green kiwi fruits per day. This intake level generally provides approximately 4 grams of dietary fiber and has been shown to be effective without causing significant adverse effects. The fruit can be eaten at any time, but some suggest consuming it with a meal to maximize the digestive action of the actinidin enzyme on dietary proteins. While many people peel kiwi fruit, the skin also contains a notable amount of fiber and can be consumed. Kiwi fruit is generally considered safe and well-tolerated, with minimal reports of adverse gastrointestinal effects compared to other fiber treatments. The primary safety consideration is the potential for allergic reactions, particularly for individuals with a latex-fruit syndrome or an allergy to the fruit itself.