Kiwifruit began as a wild Chinese fruit. The fuzzy green one in most stores, Hayward, is a single cultivar developed in New Zealand around 1924, and this page is about that green kiwifruit. Gold kiwifruit is a different species, and the study cards say so when a trial used it.
Green kiwifruit holds actinidin, an enzyme that digests protein. Gold varieties have much less or none: SunGold has far less than Hayward. In 12 older adults, two green kiwifruit a day made the amino acids from a beef meal reach the blood faster than gold kiwifruit did, though the total absorbed was the same. Actinidin is also one of the fruit’s allergens.
Much of the research was funded by Zespri, the growers’ marketing company, and we say so on each card where the paper does. In July 2025 the EU authorized a health claim that green kiwifruit contributes to normal bowel function by increasing stool frequency. One fruit (69 g) has 64 mg of vitamin C, 71% of the daily value.
Health benefits of kiwifruit
The top findings from 33 studies, strongest evidence first
What the stars mean
- Strong. Several randomized trials, pooled in a meta-analysis, point the same way, or regulators (FDA or EFSA) have approved the claim.
- Moderate. Good randomized trials support it, but there are fewer of them, or their results vary.
- Limited. Small, short or single trials, or mixed results. Promising, but it needs confirmation.
Population and lab studies get no stars: they show a link or a mechanism, not proof.
How we rate evidence →- ★★★More regular bowel movementsEating two large green kiwifruit (about 200 g of flesh) a day earned an EU health claim for normal bowel function. In people with constipation, two a day added about 1.5 complete bowel movements a week.
- ★★Mixed results on blood pressureThree kiwifruit a day for 8 weeks lowered 24-hour blood pressure more than one apple: top number by 3.6, bottom by 1.9 mm Hg. One pooled analysis found drops of 5.7 (top) and 4.1 (bottom) mm Hg, another found no significant effect.
- ★★Slightly lower LDL cholesterolA pooled analysis of 6 trials found kiwifruit lowered LDL by about 9 mg/dL, with no significant change in triglycerides or HDL. Another, of 5 trials in people with heart risk factors, saw a drop of 0.41 mmol/L that could be chance.
- ★★Less fatigue in people low in vitamin CTwo gold kiwifruit a day for 4 weeks reduced fatigue and improved well-being in young adults with low blood vitamin C. This was gold kiwifruit, not green.
- ★Higher iron stores in women with low ironTwo gold kiwifruit a day with iron-fortified cereal for 16 weeks raised iron stores more than a banana did. Median ferritin, a measure of stored iron, rose 10.0 µg/L with kiwifruit and 1.0 µg/L with banana.
All 33 studies, strongest evidence first
Green kiwifruit earned an EU health claim for normal bowel function at about 200 g of flesh a day
The European Food Safety Authority’s expert panel judged that eating green kiwifruit (the Hayward variety) and normal defecation have a cause and effect link. Each study alone had limits, but six pertinent human studies agreed that two to four green kiwifruit a day raised stool frequency, two of four that measured stool consistency also found an effect, and no diarrhea followed. The panel said two large fruit, around 200 g of flesh, give the effect. Zespri, the growers’ marketing company, applied for the claim, and the European Commission authorized it in July 2025 for fresh green kiwifruit only, not for powders or capsules.
Two green kiwifruit a day for 4 weeks added about 1.5 complete bowel movements a week in people with constipation
Randomized crossover trial in Italy, Japan and New Zealand: 63 healthy people, 60 with functional constipation and 61 with constipation-predominant irritable bowel syndrome (IBS-C) had two green kiwifruit or 7.5 g of psyllium a day, each for 4 weeks. Complete spontaneous bowel movements rose by 1.53 a week with functional constipation and 1.73 with IBS-C, and gut comfort scores improved. There were no significant side effects. Zespri was the main funder and two authors work for it.
Kiwifruit gave about 0.36 more bowel movements a week than psyllium in adults with chronic constipation
Meta-analysis of 23 studies (17 randomized trials, 1714 people) of foods, drinks and diets in chronic constipation; kiwifruit was the most tested food, in 7 studies. The difference against psyllium was 0.36 a week (range 0.24 to 0.48, 192 people), while prunes did not differ from psyllium. It is a small gain, and the authors say the evidence on foods is scarce.
Kiwifruit may add about 1 bowel movement a week over psyllium, but the pooled range just crossed zero
Meta-analysis of 7 randomized trials (399 people) of kiwifruit or kiwifruit extracts in constipation. Against psyllium the difference was 1.01 a week (range −0.02 to 2.04) and stools were softer. Against placebo, extracts did not clearly raise bowel movements (1.36, range −0.44 to 3.16) and may have caused more minor side effects. The authors rate the certainty of evidence low overall and ask for larger trials.
Three kiwifruit a day for 8 weeks lowered 24-hour blood pressure by 3.6/1.9 mm Hg compared with one apple
Randomized trial in 118 people with high-normal blood pressure or stage 1 hypertension. The 24-hour ambulatory drop was 3.6 mm Hg systolic (range 0.7 to 6.5) and 1.9 mm Hg diastolic. Office blood pressure and blood vessel function did not differ between the groups, so the cause of the drop is unclear.
A meta-analysis of 6 trials found kiwifruit lowered blood pressure by 5.7/4.1 mm Hg
Six randomized trials with 10 intervention arms. Systolic pressure fell 5.73 mm Hg and diastolic 4.08 mm Hg, with larger drops at 3 fruit a day, in people with higher starting pressure and in trials of 8 weeks or less. The authors urge caution because so few trials exist.
A meta-analysis of 5 trials found no significant effect of kiwifruit on blood pressure, cholesterol or blood sugar in people with heart risk factors
Five randomized trials with 489 people who had high cholesterol, high blood pressure, type 2 diabetes or were male smokers. Systolic pressure fell 1.72 mm Hg (range −4.27 to 0.84) and LDL cholesterol 0.41 mmol/L (range −0.99 to 0.18), both within chance. The authors see only a trend toward improvement.
A meta-analysis of 6 trials found kiwifruit lowered LDL cholesterol by about 9 mg/dL but changed little else
Six randomized trials in adults. LDL fell 9.30 mg/dL (range 1.04 to 17.56). Triglycerides, total and HDL cholesterol, fasting glucose, CRP, body weight, BMI and waist size did not change significantly.
Two gold kiwifruit a day for 4 weeks reduced fatigue and improved well-being in young adults with low vitamin C
Gold kiwifruit, not green. Placebo-controlled trial in 167 adults aged 18 to 35 with low blood vitamin C, who had 2 SunGold kiwifruit, a 250 mg vitamin C tablet or a placebo each day. Blood vitamin C reached saturation within 2 weeks in both active groups, and mood disturbance only trended better. Tablets had similar but not identical effects, and the mood outcomes were self-reported. Zespri funded the trial.
In a US trial, green kiwifruit, prunes and psyllium all raised weekly bowel movements, and kiwifruit had the fewest side effects
Partially randomized, exploratory trial in 79 adults with chronic constipation (75 with complete data: 29 on 2 green kiwifruit a day, 24 on 100 g of prunes, 22 on 12 g of psyllium) for 4 weeks. The share of responders was similar for the three. Kiwifruit improved stool consistency, straining and bloating. It was small and not fully randomized.
Two green kiwifruit a day for 4 weeks shortened colon transit time and raised bowel movements in people with IBS-C
Study in 54 patients with constipation-predominant irritable bowel syndrome and 16 healthy adults. Forty-one patients and all the healthy adults ate two Hayward green kiwifruit a day, while 13 patients took placebo capsules. Weekly bowel movements rose and colon transit time fell in the kiwifruit patients. The control group was small.
One kiwifruit per 30 kg of body weight a day for 3 weeks made stools bulkier, softer and more frequent in older adults
Crossover study in 38 healthy adults over 60 who ate their normal diet with or without kiwifruit, 3 weeks each. Kiwifruit improved every measure of laxation tested. For a 60 kg person, the dose works out to two fruit a day.
Eating 2 kiwifruit twice a day for 3 days increased water in the small bowel and colon on MRI scans
Crossover trial in 14 healthy adults who ate 2 kiwifruit twice a day or an equal-calorie maltodextrin drink. Stool was more frequent (1.46 a day against 1.14) and softer on kiwifruit. The scans may explain why. The abstract does not name the variety. Zespri funded the study and one author works there.
Three gold kiwifruit a day for 4 weeks raised complete bowel movements to 6.3 a week, against 4.5 on a fiber supplement
Gold kiwifruit, not green. Randomized single-blind crossover trial in 32 mildly constipated adults, who had 3 gold kiwifruit or 14.75 g of Metamucil (5 g of fiber) a day for 4 weeks each. The starting rate was 3.3 a week. Stools were softer with less straining, and pain, constipation and indigestion scores improved. Zespri supported the work.
Eating three gold kiwifruit a day with the skin for 4 weeks lowered the inflammation marker TNF-alpha in healthy people and in people with IBS-C
Gold kiwifruit, not green. Randomized crossover trial in 38 people (19 healthy and 19 with IBS-C) who ate 3 SunGold kiwifruit with or without the skin for 4 weeks each. TNF-alpha fell with the skin on in both groups, and in healthy people without it. Bowel movements rose and constipation and pain scores fell either way. The authors suggest the skin may add gut benefits that the flesh alone does not.
Green kiwifruit extract capsules (1 g a day) did not improve constipation in a placebo-controlled crossover trial
Forty adults with 3 or fewer bowel movements a week entered and 32 finished, taking capsules or placebo for 3 weeks each with a washout between. Bowel movements, stool type, symptom scores and quality of life did not differ. The authors suggest higher doses may be worth testing. It says little about the whole fruit.
A review of 12 trials found habitual green kiwifruit eased abdominal pain and indigestion as well as constipation
Systematic scoping review of 12 trials with 661 people (constipation, IBS-C and healthy). Pooled scores from the five trials that used the same symptom scale fell 0.85 for abdominal pain (range 0.57 to 1.1) and 0.33 for indigestion (range 0.15 to 0.52). Zespri funded the review, and 11 of the 12 trials had industry funding or support.
Three kiwifruit a day for 8 weeks lowered blood pressure by about 10/9 mm Hg in male smokers
Randomized controlled trial in 102 male smokers aged 44 to 74. Platelet aggregation fell 15% and ACE activity 11% in the kiwifruit group. A group on an antioxidant-rich diet lowered systolic pressure only if they had hypertension. The drop is larger than in other trials, so it needs confirming.
Two green kiwifruit a day for 4 weeks raised HDL cholesterol by 0.04 mmol/L in men with high cholesterol, with no change in LDL
Randomized crossover trial in 85 men with high LDL cholesterol, who ate two green kiwifruit a day with a healthy diet or the healthy diet alone. Total cholesterol, LDL, insulin, glucose, CRP and blood pressure did not differ. Triglycerides fell only in carriers of the APOE4 gene variant. The HDL rise was small.
Two green kiwifruit a day for 4 weeks did not change blood pressure in men with high cholesterol
The same 85-man crossover design, in men whose pressure was mostly normal (43.5%) or slightly raised (50.6%). Heart rate, stroke volume, cardiac output and vessel resistance did not change either.
Two gold kiwifruit before breakfast for 7 weeks did not change fasting glucose, insulin or cholesterol
Gold kiwifruit, not green. Randomized trial in 43 healthy Asian adults (42 finished) who had carbonated water with or without two fruit before breakfast. Systolic pressure was 2.7 mm Hg lower on kiwifruit (range −5.5 to 0.0), a borderline result. Uric acid and triglycerides did not rise despite the fruit sugar.
Eating 2 kiwifruit an hour before bed for 4 weeks shortened the time to fall asleep by 35% in adults with sleep problems
Small before-and-after study in 24 adults (22 women) with sleep problems and no control group. Total sleep time rose 13.4%, sleep efficiency 5.41% and the sleep quality score improved 42.4%, using a questionnaire, a diary and a wrist monitor. Without a comparison group, other causes cannot be ruled out.
Dried green kiwifruit with an evening meal improved morning alertness in young men
Randomized single-blind crossover study in 24 men, 12 good and 12 poor sleepers, who had two fresh green kiwifruit, dried kiwifruit powder with the skin, or water with an evening meal. Both forms raised a urine marker of serotonin breakdown. In poor sleepers, ease of waking improved 24% after the dried form. Each treatment was tested once, not over weeks. Zespri gave in-kind support and the fruit.
Green kiwifruit eaten with beef made amino acids appear in the blood faster than gold kiwifruit in older adults
Randomized double-blind crossover trial in 12 healthy older adults (6 men and 6 women) who ate 2 Hayward green or Hort16A gold kiwifruit a day for 14 days and again with 100 g of ground beef. Green kiwifruit contains the enzyme actinidin and this gold variety does not. The total amount absorbed and muscle protein turnover did not differ. Zespri gave grant funding but had no role in the design or write-up.
The equivalent of four gold kiwifruit a day for 4 weeks shortened head congestion and sore throat in older adults, without cutting the number of infections
Gold kiwifruit, not green. Crossover trial in 32 adults aged 65 and over comparing four kiwifruit with two bananas a day, 4 weeks each. Plasma vitamin C, vitamin E and lutein rose, while natural killer cell activity and CRP did not change. The trial was small.
Two gold kiwifruit with iron-fortified cereal for 16 weeks raised iron stores in women with low iron
Gold kiwifruit, not green. Randomized trial in 89 women aged 18 to 44 with low iron stores (69 in the final sample), who had iron-fortified cereal and milk with 2 gold kiwifruit or 1 banana each day. Median ferritin rose 10.0 µg/L with kiwifruit and 1.0 µg/L with banana. The fruit adds vitamin C, which helps iron absorption.
One gold kiwifruit a day raised blood vitamin C to a healthy level in young men, and two a day reached saturation
Gold kiwifruit, not green. Fifteen male students with below-average vitamin C ate half, one, two and then three fruit a day, 4 to 6 weeks each. Half a fruit raised blood levels, one reached the healthy range (above 50 µmol/L), and two raised it further with more vitamin C in the urine, a sign of saturation. The trial was small and men only.
Italian children who ate citrus fruit or kiwifruit 5 to 7 times a week had 34% lower odds of wheezing than those who ate them less than weekly
Survey of 18,737 children aged 6 to 7 in Italy. Citrus and kiwifruit were counted together, so kiwifruit alone is not separated out. A follow-up of 4,104 children a year later found the same pattern. Parents reported the symptoms, and other parts of the diet or home cannot be ruled out.
Among 311 people with kiwifruit allergy in Europe, reactions were more severe in those sensitized to actinidin and in Iceland
EuroPrevall study in 12 countries. Patients in Iceland mostly reacted to Act d 1, which is actinidin (32%), those in western, central and eastern Europe to Act d 8 (58% and 44%), and those in southern Europe to Act d 9 and Act d 10. The odds of severe allergy were about four times higher with Act d 1 sensitization (3.98) and 5.6 times higher in Iceland. Symptoms ranged from mild to anaphylaxis.
In UK patients with kiwifruit allergy, actinidin was not the major allergen, unlike earlier reports
Study of 76 patients with a history of kiwifruit allergy, 23 of them confirmed by a double-blind food challenge. A 38 kDa protein was recognized by 59%, and no patient’s antibodies bound actinidin on blots. The authors conclude that major allergens differ between populations.
In a Turkish kiwifruit-growing city, confirmed kiwifruit allergy affected 0.10% of schoolchildren
Cross-sectional study of 15,783 schoolchildren aged 6 to 18 in Rize who returned a questionnaire (20,800 invited). Parents reported 0.5% with IgE-mediated kiwifruit allergy, but oral food challenges confirmed 0.10%. Allergy was uncommon even where kiwifruit is widely grown and eaten.
In rats, actinidin from green kiwifruit increased stomach digestion of gluten 3.2-fold
Study in growing rats, not people. Diets with 20% freeze-dried green kiwifruit, which contains actinidin, or gold kiwifruit, which has almost none, were compared across 6 proteins. Actinidin also raised stomach digestion of beef muscle (0.6-fold) and soy protein isolate (0.6-fold), and it sped stomach emptying for some diets.
In a lab digestion model, green kiwifruit extract broke down pea protein, almonds, tofu and quinoa faster
Lab study with no people. Extracts of Hayward green and SunGold kiwifruit were added to a three-stage model of the mouth, stomach and gut. The green extract, which has more actinidin, usually broke proteins down more, including a major almond allergen. Zespri funded the work.
Who should be careful with kiwifruit
Most people can eat kiwifruit freely. Take a little care if one of these applies:
- Kiwifruit allergy. Kiwifruit is a common cause of food allergy, with reactions from mild to severe, and in a European study sensitization to actinidin, an enzyme in the fruit, went with more severe ones. It is uncommon (0.10% of schoolchildren in a Turkish kiwifruit city), but if you have reacted to it, see an allergist before trying it again.
- Irritable bowel syndrome. Monash University rates green kiwifruit low in FODMAPs at a serving of two medium fruit. Kiwifruit also softens stools, so people prone to diarrhea may want to start with one.
How to choose, store and eat kiwifruit
- Fresh green kiwifruit: the form behind the EU health claim, at about 200 g of flesh, around two large fruit, a day.
- Gold kiwifruit: a different species with much less actinidin. In a trial of mildly constipated adults, three a day raised complete bowel movements to 6.3 a week.
- Powders and capsules: the EU claim covers fresh green kiwifruit only, and extract capsules at 1 g a day did not improve constipation in a placebo-controlled trial.
Press the fruit gently: if it gives, it is ripe. Ripen firm ones in a bag with an apple or banana for a day or two, and keep them in the fridge once ripe, where unripe fruit lasts up to 6 weeks. Residues are no reason to skip it: in USDA tests of 177 kiwifruit samples in 2020, none had a residue above the legal limit.
Sources
- Commission Implementing Regulation (EU) 2025/1560 authorising a health claim on green kiwifruit. Official Journal of the European Union. 2025.
- Le TM, Bublin M, Breiteneder H, et al. Kiwifruit allergy across Europe: clinical manifestation and IgE recognition patterns to kiwifruit allergens. J Allergy Clin Immunol. 2013.
- Bublin M, Radauer C, Knulst A, et al. Effects of gastrointestinal digestion and heating on the allergenicity of the kiwi allergens Act d 1, actinidin, and Act d 2, a thaumatin-like protein. Mol Nutr Food Res. 2008.
- Haktanir Abul M, Dereci S, Hacisalihoglu S, Orhan F. Is kiwifruit allergy a matter in kiwifruit-cultivating regions? A population-based study. Pediatr Allergy Immunol. 2017.
- Zespri kiwifruit low FODMAP certified by Monash University, now listed in our app. Monash FODMAP blog. 2020.
- HappyHealthy fact sheet: kiwi. Mississippi State University Extension.
- Pesticide Data Program annual summary, calendar year 2020. USDA Agricultural Marketing Service.
History of kiwifruit
Kiwifruit is a Chinese fruit. It is native to central and eastern China, where the earliest identifiable description of the plant is in a Tang dynasty poem by Cen Shen, and the first recorded description of the fruit dates to the 12th century, in the Song dynasty. Before the 20th century it went by names such as míhóutáo, “macaque peach.”
The seeds reached New Zealand in 1904. Mary Isabel Fraser brought them back from a trip to Yichang, China, and nurseryman Alexander Allison grew plants from them. Plant scientist Ferguson notes that most of the important cultivars are selections from the wild, not the result of planned breeding programs.
New Zealand growers called it the Chinese gooseberry, a name first recorded there in 1917 that stayed standard into the 1950s. The Hayward cultivar was developed by Hayward Wright in Avondale around 1924, and commercial planting began in the 1940s. Exports to the United Kingdom and Australia began in 1953, and to California in 1959. Hayward still dominates international sales.
In 1959 the exporter Turners & Growers began using the name kiwifruit, coined by Jack Turner. According to Wikipedia, it refers to “kiwi” as a nickname for New Zealanders, not to the bird, and a US client had warned that “Chinese gooseberry” might meet trouble at quarantine. By 1970 all New Zealand exports used the new name, and the marketing board was renamed Zespri International in 1997.
Gold kiwifruit was bred in the 1980s and 1990s as the cultivar Hort16A, and it suffered heavy losses to disease. The bacterium Psa reached New Zealand in 2010 and badly damaged an industry that rested on only two cultivars. It recovered largely by switching to a less susceptible yellow-fleshed cultivar, now sold as SunGold.
China now grows most of the world’s kiwifruit: about 55% in 2023, or 2.36 million of 4.43 million tonnes, ahead of New Zealand and Italy.
Sources
- Kiwifruit. Wikipedia.
- Mary Isabel Fraser. Wikipedia.
- Ferguson AR. Kiwifruit: the wild and the cultivated plants. Adv Food Nutr Res. 2013.
- Nishiyama I. Fruits of the Actinidia genus. Adv Food Nutr Res. 2007.
- Vanneste JL. The scientific, economic, and social impacts of the New Zealand outbreak of bacterial canker of kiwifruit (Pseudomonas syringae pv. actinidiae). Annu Rev Phytopathol. 2017.
Frequently asked questions about kiwifruit
Is kiwifruit good for you?
For most people, yes. One fruit (69 g) has 42 calories, 2.1 g of fiber and 64 mg of vitamin C, 71% of the daily value. Two green kiwifruit a day raised bowel movements in people with constipation, and the EU authorized a health claim for it. The blood pressure, cholesterol and sleep results are smaller and mixed, and much of the research was funded by Zespri.
How many kiwis should you eat a day?
Two is the amount with the best evidence for bowel function. The EU claim asks for 200 g of fresh green kiwifruit flesh a day, about two large fruit; the fruit on this page weighs 69 g, so 200 g is nearer three of those. Constipation trials used 2 a day, and a blood pressure trial used 3 a day for 8 weeks. One study in older adults used 1 fruit per 30 kg of body weight.
Does kiwifruit help with constipation?
Yes, for many people with constipation, though the gain is modest. Two green kiwifruit a day added 1.53 complete bowel movements a week in functional constipation and 1.73 in IBS-C, in a trial funded by Zespri. A meta-analysis found 0.36 more bowel movements a week than with psyllium, but another rates the certainty of evidence low. Extract capsules at 1 g a day did not help in one trial.
Can you eat kiwi skin?
Yes, the skin is edible, but the fuzz on green kiwifruit makes most people peel it. No trial here tested eating the whole skin of fresh green kiwifruit. A trial of gold kiwifruit eaten with the skin found TNF-alpha, an inflammation marker, fell in healthy people and in people with IBS-C, and the authors say the skin may add gut benefits.
Does kiwifruit help you sleep?
Possibly, but the evidence is small. In 24 adults with sleep problems and no control group, 2 kiwifruit an hour before bed for 4 weeks went with a 35% shorter time to fall asleep and 13.4% more sleep. A crossover trial in 24 young men found dried green kiwifruit improved morning alertness. We found no large placebo-controlled sleep trial.
Is green or gold kiwifruit healthier?
Neither wins on everything. Green kiwifruit, the Hayward type, has the most actinidin: with beef it made amino acids appear in the blood faster than gold did in 12 older adults. Constipation trials used 2 green or 3 gold a day, and the EU claim covers green only. Gold trials found one fruit a day raised blood vitamin C to a healthy level. The nutrition numbers on this page are for green.
Does kiwifruit raise blood sugar?
Not much in these studies. In a 7-week trial in 43 healthy adults, two gold kiwifruit before breakfast did not change fasting glucose, and a meta-analysis of 5 trials found no significant effect on blood sugar in people with heart risk factors. One fruit (69 g) has 6.2 g of sugars and 2.1 g of fiber. If you have diabetes, check portions with your care team.
How many calories are in a kiwi?
One kiwifruit (69 g) has 42 calories, and 100 g has 61. Per 100 g that is 1.1 g of protein, 0.5 g of fat, 11.7 g of net carbs and 3 g of fiber.