Why YOU need to start eating KIWIS - a potential superfood

Summary

These studies suggest kiwis have numerous health benefits, including cardiovascular, digestive, immune, metabolic, and antioxidative properties, supporting their classification as a superfood.

Note: I may be slightly biased; this is in my list of top 3 fruits (and it’s not 2nd or 3rd). Thanks to Jeff Nippard for putting me on this!

Introduction

Kiwifruit, often referred to as a "superfood," is renowned for its high nutritional value and potential health benefits. This synthesis examines the evidence from multiple research studies to determine whether kiwifruit can be considered a superfood based on its health-promoting properties.

Key Insights

• Cardiovascular Health Benefits:

  • Kiwifruit consumption reduces platelet aggregation and lowers blood triglycerides, which may benefit cardiovascular health.

  • It improves lipid homeostasis and fatty acid metabolism, reducing total cholesterol and triglycerides while increasing HDL levels.

• Digestive Health:

  • Kiwifruit aids digestion and alleviates symptoms of gastrointestinal disorders, including constipation and irritable bowel syndrome, due to its fibre content and the enzyme actinidin.

  • Regular kiwifruit consumption improves bowel movements and increases the faecal content of beneficial bacteria, which may reduce the risk of colorectal cancer.

• Antioxidant Properties:

  • Kiwifruit is rich in antioxidants, including vitamins C and E, polyphenols, and flavonoids, which help scavenge free radicals and reduce oxidative stress.

  • Different varieties of kiwifruit, including kiwi berries and dwarf kiwi, exhibit high antioxidant activities, which are linked to their phenolic and flavonoid content.

• Metabolic Health:

  • Regular kiwifruit consumption can improve glucose and insulin balance, support body weight maintenance, and enhance energy homeostasis, which is crucial for metabolic health.

  • Kiwifruit seed oil has been shown to prevent obesity by regulating inflammation, thermogenesis, and gut microbiota in high-fat diet-induced obese mice.

• Gut Microbiota:

  • Kiwifruit consumption increases the richness and diversity of gut microbiota, promoting the growth of beneficial bacteria and reducing harmful bacteria.

• Cancer Prevention:

  • The high ascorbic acid content in kiwifruit helps reduce DNA oxidative injury, which may lower the risk of cancer development, particularly colorectal cancer.

Sleep

This deserves a section on its own.

• Improvement in Sleep Quality and Quantity:

  • In various studies, kiwifruit consumption has been shown to improve both sleep quality and quantity, making it a promising natural intervention for sleep enhancement.

• Mechanism of Action:

  • The sleep-promoting effects of kiwifruit, particularly its peel extracts, are believed to be mediated through a GABAergic mechanism, similar to the action of diazepam, a known sedative-hypnotic agent.

• Dose-Dependent Effects:

  • Studies indicate that the sleep benefits of kiwifruit peel extracts are dose-dependent, with higher doses leading to greater increases in sleep duration and decreases in sleep latency.

• Sustained Effects Without Tolerance:

  • Sub-chronic administration of green kiwifruit peel extract has shown sustained sleep-promoting effects without developing tolerance, suggesting its potential for long-term use.

Conclusion

Kiwifruit exhibits multiple health benefits, including cardiovascular protection, improved digestive health, potent antioxidant properties, and positive effects on metabolic health and gut microbiota. Kiwifruit, particularly its peel extracts, has demonstrated significant potential in improving sleep quality and duration through a GABAergic mechanism. These attributes collectively support the classification of kiwifruit as a superfood, making it a valuable addition to a balanced diet for promoting overall health and wellness.

Sources:

1. D. Richardson et al. "The nutritional and health attributes of kiwifruit: a review." European Journal of Nutrition, 57 (2018): 2659 - 2676.

2. Murilo Dias et al. "Chemical composition and bioactive properties of byproducts from two different kiwi varieties.." Food research international, 127 (2020): 108753 .

3. G. Lippi et al. "Kiwifruit and Cancer: An Overview of Biological Evidence." Nutrition and Cancer, 72 (2020): 547 - 553.

4. A. Duttaroy et al. "Effects of kiwi fruit consumption on platelet aggregation and plasma lipids in healthy human volunteers." Platelets, 15 (2004): 287 - 292.

5. Jiyue Zhang et al. "Assessment of the phytochemical profile and antioxidant activities of eight kiwi berry (Actinidia arguta (Siebold & Zuccarini) Miquel) varieties in China." Food Science & Nutrition, 9 (2021): 5616 - 5625.

6. HyeJin Yang et al. "Green and gold kiwifruit peel ethanol extracts potentiate pentobarbital-induced sleep in mice via a GABAergic mechanism.." Food chemistry, 136 1 (2013): 160-3 .

7. Madeleine Gratwicke et al. "Nutritional Interventions to Improve Sleep in Team-Sport Athletes: A Narrative Review." Nutrients, 13 (2021).

8. Duhyeon Kim et al. "Effects of Green Kiwifruit Peel Extract on Sleep-Wake Profiles in Mice: A Polysomnographic Study Based on Electroencephalogram and Electromyogram Recordings." Nutrients, 14 (2022).

9. Ronan J. Doherty et al. "Sleep and Nutrition Interactions: Implications for Athletes." Nutrients, 11 (2019).

🌟 Thank you for joining us 

We want to extend our heartfelt gratitude for taking the time to read our newsletter. As qualified doctors, we want to learn more about optimising our health and the health of our loved ones with accurate and evidence-based information in an era where misinformation can cloud our understanding of health. We’re also the first to share this with the public because everyone deserves access to credible health insights.

💬 Your feedback is invaluable to us

Feedback fuels our motivation to continually improve and refine our content. Whether it's a suggestion or a correction, we welcome your input with open arms. After all, our goal is to cater to our combined curiosity and answer health-related questions. Just reply to this email 😄 

🌐 Topic Suggestion

We invite you to continue participating actively in our community as we progress. Share your thoughts, ask questions, and tell us what topics interest you. Is there a specific health condition you'd like us to cover? Are there wellness practices you're interested in exploring? Feel free to reach out to us with your thoughts and ideas. We're here to learn, share, and grow as a community of health enthusiasts. Feel free to hit reply to this email! Together, let's navigate the vast landscape of health with clarity and accuracy.

Thank you once again for being a part of our health-focused family. Stay curious, stay healthy, and stay connected!

Disclaimer:

By subscribing to and reading this newsletter, you acknowledge and agree that you voluntarily choose to read the content and use this information at your own risk.

The information provided in this newsletter, including text, graphics, images, and other material, is for informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. The content is not intended to replace the advice of a qualified healthcare professional.

While the information is based on research, it should not be used to disregard or delay seeking advice from a healthcare provider. Always consult a healthcare professional before deciding about your health or medical conditions.

The authors of this newsletter, including qualified doctors, have made every effort to ensure that the information is accurate and current. However, medical knowledge is constantly evolving, and errors can occur. Therefore, this newsletter's authors, editors, and publishers cannot be held responsible for the information's accuracy, completeness, or suitability for any particular individual or situation.

This newsletter's authors, editors, and publishers are not liable for any direct, indirect, consequential, special, exemplary, or other damages arising from applying the information in this newsletter.