Home > Food and Drink, Heart Health, Women's Health > Kiwi Fruit Revelations

Kiwi Fruit Revelations

February 6, 2012 Written by JP       [Font too small?]

Nutritionists often advocate more fruits and vegetables in the average person’s diet. This is good, albeit incomplete advice. It’s kind of like saying, “Walking is a great form of exercise”. However, walking in a lush park is far more advisable than walking alongside a polluted downtown street. Likewise, increased consumption of just any fruits and vegetables won’t necessarily promote better health. Rather, focusing on low-glycemic, nutrient dense produce is a much better strategy. In practical terms, this means opting for leafy green vegetables instead of potatoes and fruits like kiwis instead of bananas.

Kiwis are an extraordinary and underappreciated fruit. They’re low in calories, rich in nutrients and suitable for just about anyone – including many diabetics. The medical literature is replete with examples of why we should all consider eating more of this exotic fruit. For starters, several recent studies reveal that eating kiwi fruits daily effectively: lowers diastolic blood pressure by 9 mm Hg and systolic blood pressure by 10 mm Hg; improves circulation by inhibiting platelet aggregation; and elevates HDL (“good”) cholesterol. These findings are very encouraging, but not altogether unexpected. Kiwis are an abundant source of cardioprotective nutrients (fiber, potassium and Vitamin K) and potent antioxidants (lutein, Vitamin C and zeaxanthin), which theoretically should benefit heart health. The difference now is that we have scientific evidence to confirm this assumption.

The cardiovascular benefits conferred by kiwis is reason enough to recommend them. But, what’s truly fascinating is the sheer breadth of their health promoting potential. Current research reports that eating kiwis daily: 1) reduces the duration and severity of upper respiratory tract infections; 2) benefits sleep quality by hastening sleep onset; 3) regulates reproductive hormones and symptoms relating to peri-menopause; 4) enhances the absorption of dietary and supplemental iron; 5) gently relieves constipation in various populations including children and those with irritable bowel syndrome; 6) improves lung function in youngsters with wheezing symptoms; 7) supports healthier vision thanks to high concentrations of antioxidant carotenoids.

Most of the studies  referenced today utilized 2 to 4 kiwis daily. This is a reasonable amount for most people to enjoy provided that no allergy to kiwi is known or suspected. Allergic reactions to this otherwise amazing fruit are indeed possible and can be severe. When selecting kiwis, it’s important to note that conventionally grown varieties are fine to purchase. A recent analysis by the Environmental Working Group determined that non-organic kiwis contain very low pesticide residues. I recommend eating kiwis along with a good source of fat in order to enhance the absorption of the fat soluble antioxidants and nutrients. Personally, I like to eat with them with Greek yogurt or organic cottage cheese. They can also be mixed into smoothies containing organic coconut milk as a source of healthy lipids. And, if you ask me, adding organic strawberries to the mix makes it even better.

Note: Please check out the “Comments & Updates” section of this blog – at the bottom of the page. You can find the latest research about this topic there!

To learn more about the studies referenced in today’s column, please click on the following links:

Study 1 – Kiwifruit Decreases Blood Pressure and Whole-Blood Platelet (link)

Study 2 - Effects of Kiwifruit Consumption on Serum Lipid Profiles and (link)

Study 3 – Consumption of Gold Kiwifruit Reduces Severity and Duration of (link)

Study 4 - Effect of Kiwifruit Consumption on Sleep Quality in Adults w/ Sleep (link)

Study 5 - A Preliminary Study of the Effectiveness of Chinese Therapeutic Food (link)

Study 6 - Gold Kiwifruit Consumed with an Iron-Fortified Breakfast Cereal Meal (link)

Study 7 - Kiwifruit Improves Bowel Function in Patients with Irritable Bowel (link)

Study 8 - Increasing Dietary Fiber Intake in Terms of Kiwifruit Improves (link)

Study 9 - Consumption of Fresh Fruit Rich in Vitamin C and Wheezing Symptoms (link)

Study 10 - Fruits and Vegetables That are Sources for Lutein and Zeaxanthin (link)

Kiwis Contain High Concentrations of Antioxidants Including Vitamin C

Source: British Journal of Nutrition (2002), 87 : pp 55-59 (link)

Bookmark and Share


Related Posts:

Tags: , ,
Posted in Food and Drink, Heart Health, Women's Health

12 Comments & Updates to “Kiwi Fruit Revelations”

  1. Orna Izakson, ND, RH (AHG) Says:

    Another great one, JP!

    These studies presumably looked at the common fuzzy kiwi (Actinidia deliciosa), which can be expensive or difficult to find in some places. But a lot of folks can grow them at home. A. deliciosa needs some warmth, but there are two other species that would likely have similar health benefits but are much hardier. A. arguta is known as hardy kiwi, and A. kalomikta is known as arctic beauty. Both are beautiful vines, grow grape-sized kiwi fruit with smooth skins and taste much like their larger fuzzy cousin.

    Here’s where I get mine, though they’re available at more and more nurseries these days: http://www.burntridgenursery.com/fruitingPlants/index_product.asp?dept=25&parent=23

  2. JP Says:

    Thank you for sharing that, Orna! Home grown fruits and vegetables are an excellent way to improve one’s health. My parents are an inspiration in that respect. They grow many of the fruits and veggies they eat on a daily basis. They also share the excess with their friends and neighbors. A wonderful example for us all! :-)

    Be well!

    JP

  3. liverock Says:

    Good on your parents for sharing their fruit and veg JP!

    What neighbourhoods need more than anything right now is a greater sense of community and this sort of action can help the sense of community grow.

    This town has the right idea which grows fruit and veg in public places and lets anybody pick it.

    http://www.dailymail.co.uk/femail/article-2072383/Eccentric-town-Todmorden-growing-ALL-veg.html#ixzz1gc26xy83

  4. JP Says:

    What an inspirational story, Liverock! Just great. :)

    Recently, I was doing some research on the many health benefits of gardening. Combine those with the satisfaction of contributing something positive to the community and you’ve got an even better scenario. Talk about a “grass roots” movement. ;)

    Be well!

    JP

  5. Mark Says:

    Thanks for the article! I wonder if the stated lowering of blood pressure is in fact more of a healthy normalizing, than a tendency towards lowering. I have quite low blood pressure and there is very little research into healthy foods that raise it. There is are a lot of warning about unhealthy foods that raise it, but that’s not quite what I’m after. ;)

  6. JP Says:

    Hi Mark,

    That may very well be the case. In many instances, substances that lower blood pressure (be they foods or supplements) primarily do so in established hypertensives. This argues for a normalizing effect.

    Please take a look at this piece about hypotension. There are some suggestions that you might want to consider – if you haven’t already.

    http://www.mayoclinic.com/health/low-blood-pressure/DS00590/METHOD=print

    Be well!

    JP

  7. Nina K. Says:

    Hiya JP ☺

    great article (as always)about KIWI ☺. Helps me through the cold days with lots of vitamin c!

    Be well!

    Nina K.

  8. JP Says:

    Update 07/26/15:

    http://www.nrjournal.com/article/S0271-5317%2815%2900071-8/fulltext

    Nutr Res. 2015 May;35(5):401-8.

    Kiwifruit-derived supplements increase stool frequency in healthy adults: a randomized, double-blind, placebo-controlled study.

    The worldwide growth in the incidence of gastrointestinal disorders has created an immediate need to identify safe and effective interventions. In this randomized, double-blind, placebo-controlled study, we examined the effects of Actazin and Gold, kiwifruit-derived nutritional ingredients, on stool frequency, stool form, and gastrointestinal comfort in healthy and functionally constipated (Rome III criteria for C3 functional constipation) individuals. Using a crossover design, all participants consumed all 4 dietary interventions (Placebo, Actazin low dose [Actazin-L] [600 mg/day], Actazin high dose [Actazin-H] [2400 mg/day], and Gold [2400 mg/day]). Each intervention was taken for 28 days followed by a 14-day washout period between interventions. Participants recorded their daily bowel movements and well-being parameters in daily questionnaires. In the healthy cohort (n = 19), the Actazin-H (P = .014) and Gold (P = .009) interventions significantly increased the mean daily bowel movements compared with the washout. No significant differences were observed in stool form as determined by use of the Bristol stool scale. In a subgroup analysis of responders in the healthy cohort, Actazin-L (P = .005), Actazin-H (P < .001), and Gold (P = .001) consumption significantly increased the number of daily bowel movements by greater than 1 bowel movement per week. In the functionally constipated cohort (n = 9), there were no significant differences between interventions for bowel movements and the Bristol stool scale values or in the subsequent subgroup analysis of responders. This study demonstrated that Actazin and Gold produced clinically meaningful increases in bowel movements in healthy individuals.

    Be well!

    JP

  9. JP Says:

    Update 07/26/15:

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4425162/

    Nutrients. 2015 Apr 9;7(4):2574-88.

    Enhanced human neutrophil vitamin C status, chemotaxis and oxidant generation following dietary supplementation with vitamin C-rich SunGold kiwifruit.

    Neutrophils are the body’s primary defenders against invading pathogens. These cells migrate to loci of infection where they engulf micro-organisms and subject them to an array of reactive oxygen species and antimicrobial proteins to effect killing. Spent neutrophils subsequently undergo apoptosis and are cleared by macrophages, thereby resolving the inflammatory episode. Neutrophils contain high concentrations of vitamin C (ascorbate) and this is thought to be essential for their function. This may be one mechanism whereby vitamin C enhances immune function. The aim of our study was to assess the effect of dietary supplementation with vitamin C-rich SunGold kiwifruit on four important functions of neutrophils: chemotaxis, oxidant generation, extracellular trap formation, and apoptosis. Fourteen young men (aged 18-30 years) with suboptimal plasma vitamin C status (<50 μmol/L) were supplemented for four weeks with two SunGold kiwifruit/day. Plasma vitamin C status was monitored weekly and neutrophil vitamin C levels were assessed at baseline and post-intervention. Neutrophil function assays were carried out on cells isolated at baseline and post-intervention. Plasma vitamin C levels increased to >70 μmol/L (p < 0.001) within one week of supplementation and there was a significant increase in neutrophil vitamin C status following four weeks’ intervention (p = 0.016). We observed a significant 20% increase in neutrophil chemotaxis post-intervention (p = 0.041) and also a comparable increase in oxidant generation (p = 0.031). Supplementation did not affect neutrophil extracellular trap formation or spontaneous apoptosis. Our data indicate that supplementation with vitamin C-rich kiwifruit is associated with improvement of important neutrophil functions, which would be expected to translate into enhanced immunity.

    Be well!

    JP

  10. JP Says:

    Update 07/26/15:

    http://informahealthcare.com/doi/abs/10.3109/08037051.2014.976979

    Blood Press. 2015 Feb;24(1):48-54. doi:

    The effect of kiwifruit consumption on blood pressure in subjects with moderately elevated blood pressure: a randomized, controlled study.

    BACKGROUND AND AIMS: Kiwifruit contains bioactive substances that may lower blood pressure (BP) and improve endothelial function. We examined the effects of adding kiwifruit to the usual diet on 24-h ambulatory BP, office BP and endothelial function.

    METHODS: In a parallel-groups study, 118 subjects with high normal BP or stage 1 hypertension (systolic BP 130-159 mmHg and/or diastolic BP 85-99 mmHg) were randomized to intake of three kiwifruits (intervention) or one apple (control) a day for 8 weeks. Office and 24-h ambulatory BP was measured along with biomarkers of endothelial function including metabolites of nitric oxide (NO) formation and finger photo-plethysmography.

    RESULTS: At randomization, mean 24-h ambulatory systolic/diastolic BP was 133 ± 13/82 ± 9 mmHg (n = 106). After 8 weeks, BP was lower in the group assigned to kiwifruit versus apple intake (between group difference, – 3.6 mmHg [95% CI - 6.5 to - 0.7], p = 0.017 and – 1.9 mmHg [95% CI - 3.6 to - 0.3]; p = 0.040, for systolic and diastolic BP, respectively). Changes in office BP and endothelial function did not differ between the groups.

    CONCLUSIONS: Among men and women with moderately elevated BP, intake of three kiwifruits was associated with lower systolic and diastolic 24-h BP compared with one apple a day. The effect may be regulated by mechanisms other than improvement of endothelial function.

    Be well!

    JP

  11. JP Says:

    Update 07/26/15:

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4155706/

    J Res Med Sci. 2014 Jun;19(6):520-4.

    Effects of topical Kiwifruit on healing of neuropathic diabetic foot ulcer.

    BACKGROUND: Kiwifruit (Actindia Deliciosa) is demonstrated to have antibacterial and pro-angiogenic effects. It also contains proteolytic enzymes (actinidin) and ascorbic acid. In this study, the effects of Kiwifruit on neuropathic diabetic foot ulcer healing in clinical settings were evaluated.

    MATERIALS AND METHODS: In this randomized clinical trial of 37 patients (17 in experimental and 20 in control groups) with neuropathic diabetic foot ulcer were studied in Isfahan-Iran. Patients of the control group received just the standard treatments. In the experimental group, in addition to the standard treatments, ulcers were dressed with pure extract of kiwifruit twice daily for 21 days. The ulcers were examined and evaluated based on macroscopic, microscopic and microbiological status. Pre- and post-interventions, biopsies were taken from the ulcers to perform microbiological and histological studies.

    RESULTS: Mean reduction in surface area of foot ulcer in the experimental group was significantly higher than the control group (168.11 ± 22.31 vs. 88.80 ± 12.04 mm(2) respectively, P < 0.0001). The amount of collagen and granulation tissues was significantly higher in the experimental groups than the control group (P value < 0.0001). Significantly higher levels of angiogenesis and vascularization were found in the kiwifruit treated patients (P value < 0.0001). No significant antibacterial effect was observed for kiwifruit.

    CONCLUSION: Natural compounds in the kiwifruit including protein-dissolving enzymes (Actinidin) improved different aspects of the wound healing process. Based on these benefits and safety aspects, we conclude that using kiwifruit is a simple, applicable and effective way for treatment of neuropathic diabetic foot ulcer.

    Be well!

    JP

  12. JP Says:

    Updated 09/22/15:

    http://www.nutritionj.com/content/14/1/97

    Nutr J. 2015 Sep 15;14(1):97.

    Effects of kiwi consumption on plasma lipids, fibrinogen and insulin resistance in the context of a normal diet.

    BACKGROUND AND AIMS: Among fruits, kiwi is one of the richest in vitamins and polyphenols and has strong anti-oxidant effects. We aimed to analyze the relationship between the consumption of kiwi and plasma lipid values, fibrinogen, and insulin resistance in adults within the context of a normal diet and physical-activity.

    METHODS: Cross-sectional study. Participants (N = 1469), who were free of cardiovascular diseases, completed a visit, which included the collection of information concerning the participant’s usual diet and kiwi consumption using a previously validated, semi-quantitative, 137-item food-frequency-questionnaire. Fasting laboratory determinations included plasma lipids, fibrinogen and insulin resistance. Regular physical-activity was determined using accelerometry.

    RESULTS: Consumers of at least 1 kiwi/week presented higher plasma values of HDL-cholesterol (mean difference 4.50 [95 % CI: 2.63 to 6.36]) and lower triglyceride values (mean difference -20.03 [95 % CI: -6.77 to -33.29]), fibrinogen values (mean difference -13.22 [95 % CI: -2.18 to -24.26]) and HOMAir values (mean difference -0.30 [95 % CI: -0.09 to -0.50]) (p < 0.05, for all comparisons) than those who consumed less than 1 kiwi per week. In an adjusted logistic regression analysis, this group had a lower odds-ratio for presenting plasmatic fibrinogen concentrations above 400 mg/dL (OR = 0.68, 95 % CI 0.49 to 0.95), HDL-Cholesterol plasma values below 45 mg/dL (OR = 0.57, 95 % CI 0.36 to 0.91) and a HOMAir above 3 (OR = 0.61, 95 % CI 0.37 to 1.00).

    CONCLUSIONS: Consumption of at least one kiwi/week is associated with lower plasma concentrations of fibrinogen and improved plasma lipid profile in the context of a normal diet and regular exercise.

    Be well!

    JP

Leave a Comment




*
To prove you're a person (not a spam script), type the security word shown in the picture. Click on the picture to hear an audio file of the word.
Click to hear an audio file of the anti-spam word