Grape
Food · Fruit · Food, Typed Supps
The different colours are mostly a difference in pigment, not in sugar.
Stage by stage
- Intake (Skin ruptured): Chewing breaks the skin, releasing the pigments and polyphenols that distinguish one colour from another.
- Digestion (Free sugars, no hydrolysis needed): Glucose and fructose arrive already free, so absorption begins almost at once with little fibre to slow it.
- Absorption (Rapid sugar uptake): Sugars are absorbed quickly; polyphenols are absorbed poorly and mostly travel on to the colon.
- Use (Energy and microbial metabolites): Sugar is used or stored, while gut bacteria convert the polyphenols into the smaller phenolic acids that reach the circulation.
Time to effect
- Under an hour: Blood glucose rises within roughly 30 to 60 minutes of a normal serve.
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, Low-FODMAP, Gluten-free.
In season
August to October in the northern hemisphere, February to April in the southern.
Satiety
145 on the satiety index, where white bread is 100 — high. Modelled from the Holt et al. (1995) measurements.
Environmental footprint
1.5 kg CO2e and 420 litres of freshwater per kg, matched to "Berries & grapes" 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: 66
- Protein: 0.8g
- Carbohydrate: 15.8g
- of which sugars: 15.4g
- Fat: 0g
- of which saturated: 0g
- Fibre: 1g
- Sodium: 0mg
Food vs. supplement
Grape seed extract and resveratrol capsules deliver doses that no realistic amount of fruit approaches, and the evidence that those doses help healthy people is weak. Grapes earn their place as fruit — water, potassium, a little fibre and a genuinely varied polyphenol mix — not as a dilute supplement.
Kitchen tip
Wash and decant into a bowl rather than eating from the bunch. For anyone watching glucose, eating grapes after a meal rather than alone flattens the rise more than any choice between varieties.
Common myth
"Red grapes are much healthier than green, because of resveratrol." In reality: Red and black skins do carry anthocyanins that green ones lack, but the resveratrol dose from any grape is a small fraction of a milligram — thousands of times below the doses used in the studies that made it famous. Choose the colour you will actually eat.
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