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Kiwi

Also known as: Actinidia deliciosa, Kiwi, Chinese gooseberry, Kiwifruit, Hayward kiwi

Overview

Kiwifruit, scientifically known as *Actinidia deliciosa*, is a nutrient-dense fruit originating from China but now cultivated worldwide. It is recognized for its high content of dietary fiber, vitamins (particularly vitamin C), minerals, and a unique proteolytic enzyme called actinidin. Kiwifruit is commonly consumed as a dietary supplement to support digestive health, especially in managing constipation. The fruit's composition contributes to its beneficial effects, promoting regular bowel movements and improving stool consistency. Available in various forms, including whole fruit, extracts, and powders, kiwifruit offers a natural approach to enhancing gastrointestinal function. Research suggests that regular consumption can lead to increased frequency of bowel movements and reduced abdominal discomfort. However, the quality of evidence is still considered low to moderate, highlighting the need for more extensive and rigorous studies to fully validate its benefits.

Benefits

Kiwifruit offers several evidence-based benefits, primarily related to digestive health. It has been shown to increase the frequency of spontaneous bowel movements (SBM) compared to placebo and psyllium, though the certainty of this evidence is low to moderate. Studies indicate a potential reduction in abdominal pain associated with constipation. Kiwifruit may also improve stool type, leading to softer stools as measured by the Bristol Stool Scale. Some evidence suggests a reduction in straining during defecation, though this finding is less robust. These benefits are particularly relevant for healthy adults experiencing functional constipation. While the effect sizes are generally modest, the improvements in bowel movement frequency and abdominal pain reduction support the clinical significance of kiwifruit consumption. Benefits are typically observed within a few days to four weeks of regular intake.

How it works

Kiwifruit's mechanism of action involves several biological pathways. Its high fiber content increases bulk and water absorption in the intestines, facilitating regular bowel movements. Actinidin, a proteolytic enzyme present in kiwifruit, aids in the breakdown of proteins, potentially improving gut motility and digestion. Kiwifruit interacts with the gastrointestinal system by enhancing gut motility, improving stool consistency, and alleviating symptoms of constipation. While the exact molecular targets are not fully understood, actinidin's role in protein digestion and its potential impact on gut health are recognized. The nutrients and actinidin from kiwifruit are generally well-absorbed, owing to its high water content and easily digestible fiber.

Side effects

Kiwifruit and its extracts are generally considered safe for consumption, with few reported adverse effects. Common side effects, occurring in a small percentage of users, may include minor gastrointestinal discomfort. Allergic reactions to kiwifruit are possible but uncommon. Severe allergic reactions, such as anaphylaxis, are rare but can occur in individuals with known allergies. There are no well-documented drug interactions, but caution is advised for individuals taking anticoagulant medications due to the high vitamin K content in kiwifruit. Individuals with known allergies to kiwifruit should avoid its consumption. Pregnant or breastfeeding women should consult healthcare providers before using kiwifruit supplements, although whole kiwifruit is generally considered safe. It's important to note that while kiwifruit is generally safe, encapsulated extracts may increase the risk of gastrointestinal discomfort compared to placebo.

Dosage

The minimum effective dose of kiwifruit is not definitively established, but studies have used forms providing approximately 1-2 grams of fiber per serving. Optimal dosages typically range from one to two kiwifruits per day or equivalent extracts/powders, although more research is needed to refine precise dosing guidelines. There is no established maximum safe dose, but excessive consumption may lead to gastrointestinal discomfort due to the high fiber content. Kiwifruit or its extracts can be consumed with meals to aid digestion and reduce potential gastrointestinal side effects. Whole kiwifruit is often preferred due to its balanced nutrient profile. Adequate hydration is essential to maximize the benefits of the fiber content. No specific cofactors are required, but a balanced diet supports the digestive benefits of kiwifruit.

FAQs

Is kiwifruit safe to consume?

Kiwifruit is generally safe, but individuals with allergies or those taking certain medications, like anticoagulants, should exercise caution. Consult a healthcare provider if you have concerns.

When is the best time to eat kiwifruit?

Consuming kiwifruit with meals can aid in digestion and minimize potential side effects. It can be incorporated into breakfast, lunch, or dinner.

How long does it take to see results from eating kiwifruit?

Users may experience improvements in bowel movement frequency, stool consistency, and reduced abdominal pain within a few days to weeks of regular consumption.

Is kiwifruit a quick fix for constipation?

Kiwifruit is not a quick fix but rather a dietary addition that can support long-term digestive health. Consistent consumption is key to experiencing its benefits.

Research Sources

https://pubmed.ncbi.nlm.nih.gov/36247043/ – This systematic review and meta-analysis, involving 399 participants with constipation, found that kiwifruit extracts may increase the frequency of spontaneous bowel movements, reduce abdominal pain, and improve stool type compared to placebo and psyllium. The certainty of evidence was rated as low to moderate due to the limited number of studies and variability in outcomes, using the GRADE approach for assessment.
https://onlinelibrary.wiley.com/doi/abs/10.1155/2022/7596920 – This systematic review and meta-analysis, including 175 subjects with functional constipation, showed that kiwifruit significantly increased defecation frequency and improved stool texture. The evidence was considered low quality due to heterogeneity in study designs and outcomes, highlighting the need for larger, more rigorous trials. The Risk of Bias 2 (RoB2) instrument was used for critical appraisals.
https://jmla.pitt.edu/ojs/jmla/article/download/1223/1368 – This URL links to an article discussing consistency in search strategies for systematic reviews, emphasizing the importance of thorough and reproducible methods. While not directly related to kiwifruit's effects, it underscores the methodological rigor needed in research synthesis.
https://www.researchgate.net/post/How-important-is-consistency-of-your-search-strategies-in-conducting-systematic-reviews – This ResearchGate post discusses the importance of consistency in search strategies for conducting systematic reviews. It highlights the need for thorough and reproducible methods to ensure the reliability and validity of research findings.
https://biomedpharmajournal.org/vol17no2/a-systematic-review-and-meta-analysis-of-kiwifruits-impact-on-functional-constipation/ – This systematic review and meta-analysis examines the impact of kiwifruit on functional constipation. The study provides evidence suggesting that kiwifruit consumption can lead to improvements in bowel function for individuals experiencing constipation.