Blackberries
Food · Fruit · Food, Typed Supps
One of the few fruits with enough vitamin K that it matters for anyone on blood thinners.
Stage by stage
- Intake (Soft, minimal chewing): Their soft, aggregate structure needs very little mechanical breakdown.
- Stomach (Sugars & fibre digest): Natural sugars digest quickly while fibre slows the overall rate.
- Small intestine (Fibre, vitamin C & K absorbed): Fibre and vitamin C absorb via dedicated pathways; fat-soluble vitamin K absorbs alongside dietary fat.
- Immune & clotting (Immune support & clotting factors): Vitamin C supports immune function; vitamin K activates clotting factors in the liver.
Timing
Any time, fresh or frozen. If on warfarin or a similar blood thinner, keep vitamin K intake consistent rather than avoiding it.
Time to effect
- Days to weeks: Vitamin K affects clotting factor synthesis within days; fibre and antioxidant benefits build with sustained regular 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: Keto, Low-FODMAP.
In season
August to October in the northern hemisphere, February to April in the southern.
Satiety
239 on the satiety index, where white bread is 100 — very 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
Mid — roughly £9 per kg, as a band midpoint rather than a price.
Key nutrients
Nutrition per 100g
- Calories: 45.9
- Protein: 1.2g
- Carbohydrate: 7.4g
- of which sugars: 7.4g
- Fat: 0.3g
- of which saturated: 0g
- Fibre: 4.5g
- Sodium: 1mg
Food vs. supplement
A cup of blackberries delivers 7.6g fibre and a real dose of vitamin K (24% DV) alongside vitamin C — a plain antioxidant or vitamin C supplement provides neither the fibre nor the K.
Kitchen tip
Don’t wash until ready to eat — they only keep 2 to 3 days fresh. Frozen retains comparable nutrients.
Common myth
“All berries are nutritionally the same.” In reality: Blackberries specifically combine unusually high fibre with unusually high vitamin K compared to other common berries — a real distinction, and one worth knowing if you take a blood thinner like warfarin.
Recipes that use it
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