Kiwifruit
Food · Fruit · Food, Typed Supps
Gold kiwifruit is sweeter with more vitamin C; green is sharper with more fibre and more of the enzyme that helps digest protein.
Stage by stage
- Intake (Actinidin released): Chewing ruptures the cells and releases actinidin, the protease responsible for the tingle green kiwifruit leaves on the tongue.
- Stomach (Assists protein breakdown): Actinidin stays active at stomach pH and measurably speeds the digestion of meat and dairy protein eaten alongside it.
- Small intestine (Vitamin C absorbed): Ascorbate is taken up by sodium-dependent transporters; one gold fruit exceeds the adult daily requirement.
- Large intestine (Fibre holds water): Pectic fibre retains water and increases stool bulk, the basis of the constipation evidence, which used green fruit.
Time to effect
- Days: Where kiwifruit affects regularity, the change generally appears within three to seven days of daily intake.
Allergens
None of the fourteen major allergens. Derived from what this food is, not from a product label.
Eating patterns
Fits: Vegan, Vegetarian, Pescatarian, Halal, Kosher, Gluten-free. Depends on the product: Low-FODMAP.
Satiety
164 on the satiety index, where white bread is 100 — high. Modelled from the Holt et al. (1995) measurements.
Environmental footprint
1.1 kg CO2e and 199 litres of freshwater per kg, matched to "Other fruit" in Poore & Nemecek (2018), Science 360.
Cost band
Cheap — roughly £3 per kg, as a band midpoint rather than a price.
Key nutrients
Nutrition per 100g
- Calories: 58
- Protein: 1.2g
- Carbohydrate: 11.1g
- of which sugars: 10.9g
- Fat: 0.5g
- of which saturated: 0g
- Fibre: 1.8g
- Sodium: 3mg
Food vs. supplement
A vitamin C tablet beats either cultivar on ascorbate alone, and absorption efficiency falls as the dose climbs. What no tablet replicates is the fibre and the digestive enzyme, and those are what the more interesting kiwifruit trials actually tested.
Kitchen tip
Eat the skin if you can tolerate it, since it roughly doubles the fibre. Keep raw kiwifruit out of gelatine desserts and away from cream, as actinidin breaks both down; blanching briefly deactivates it.
Common myth
"Gold and green kiwifruit are the same thing in different colours." In reality: They were bred in different directions. Gold carries appreciably more vitamin C and is sweeter and lower in acid; green carries more fibre and much more actinidin, and it is green fruit that the constipation trials used. The right one depends on why you are eating it.
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