Flaxseed

Food · Fat & Oil · Food, Typed Supps

A plant omega-3 source your body converts far less efficiently than fish oil.

Stage by stage

Intake (Whole seeds pass through intact): Whole seeds largely pass through undigested unless ground first.
Stomach (Oil & fibre released): Ground flax begins releasing its oil and fibre.
Small intestine (ALA & fibre absorbed): ALA (a plant omega-3) and soluble fibre are absorbed.
Liver (Partial conversion to EPA/DHA): A small fraction of ALA is converted to the more active EPA/DHA forms.

Timing

Ground flaxseed is absorbed far better than whole seeds, which often pass through the gut undigested.

Time to effect

Weeks: Regular intake contributes to fibre intake and, more gradually, omega-3 status.

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, Keto, Gluten-free. Depends on the product: Low-FODMAP.

Satiety

161 on the satiety index, where white bread is 100 — high. Modelled from the Holt et al. (1995) measurements.

Cost band

Pricey — roughly £12 per kg, as a band midpoint rather than a price.

Key nutrients

ALA (plant omega-3)
Soluble & insoluble fibre
Lignans
Magnesium

Nutrition per 100g

Calories: 450
Protein: 21.6g
Carbohydrate: 2.8g
of which sugars: 1.5g
Fat: 32.6g
of which saturated: 3.3g
Fibre: 32.9g
Sodium: 60mg

Food vs. supplement

The body converts only a small percentage of flaxseed’s ALA into the more active EPA/DHA forms found directly in fish oil — flaxseed is a genuine omega-3 source, just a much less efficient one gram-for-gram than fish or algae oil.

Kitchen tip

Grind it fresh in a coffee grinder and store it in the fridge — pre-ground flax oxidizes and loses potency faster than the whole seed.

Common myth

Flaxseed and fish oil provide the same omega-3 benefit. In reality: They both provide omega-3s, but flaxseed’s ALA converts to EPA/DHA at a low rate in the body — fish oil delivers those active forms directly.

Recipes that use it

In the glossary

Absorption