Apple

Food · Fruit · Food, Typed Supps

Most of its fibre, and a notable antioxidant, live in the skin.

Stage by stage

Intake (Skin-concentrated compounds): Chewing with skin on releases fibre and plant compounds concentrated there.
Stomach (Pectin forms a gel): Its soluble fibre (pectin) begins forming a gel, similar to oats’ beta-glucan.
Small intestine (Slows sugar absorption): Pectin slows sugar absorption; quercetin and other polyphenols are absorbed, mostly from the skin.
Bloodstream & gut (Antioxidant activity & fermentation): Absorbed polyphenols circulate with antioxidant activity; unabsorbed fibre feeds gut bacteria.

Timing

Skin on retains the most fibre and polyphenol content.

Time to effect

Hours: Pectin begins slowing sugar absorption within the same meal.

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.

In season

September to December in the northern hemisphere, March to June in the southern.

Satiety

197 on the satiety index, where white bread is 100 — very high. Measured by Holt et al. (1995).

Environmental footprint

0.4 kg CO2e and 180 litres of freshwater per kg, matched to "Apples" in Poore & Nemecek (2018), Science 360.

Cost band

Cheap — roughly £2 per kg, as a band midpoint rather than a price.

Key nutrients

Pectin (soluble fibre)
Quercetin (in skin)
Vitamin C

Nutrition per 100g

Calories: 51.9
Protein: 0.3g
Carbohydrate: 11.8g
of which sugars: 11.6g
Fat: 0g
of which saturated: 0g
Fibre: 2.4g
Sodium: 1mg

Food vs. supplement

Peeling an apple removes much of its fibre and nearly all its quercetin — a quercetin supplement delivers an isolated, concentrated dose, while the whole apple delivers a smaller amount alongside fibre and water.

Kitchen tip

Most of the fibre and a good share of the antioxidants sit in and near the skin - peeling it removes a real chunk of the benefit.

Common myth

“Apple juice offers the same benefits as a whole apple.” In reality: Juicing removes virtually all the fibre and much of the skin-concentrated quercetin, leaving mostly sugar and water.