Know2eat

Leek

Allium ampeloprasum var. porrum

What leek has been studied for

2 associations assessed — 2 with at least some human evidence behind them. Strongest first.

  • 2 Limited
3 things to know first — allergies, interactions and intake limits

About leek

An allium grown for its thick blanched stem of tightly wrapped leaf sheaths rather than a bulb. Milder and sweeter than onion, and the standard aromatic base of northern European soups.

Also known as Leeks, Poireau, Porrum

Heart HealthGut & Digestive Health

The evidence in depth

Best supported: Limited

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how impressive the food is. How we rate evidence.

Cardiovascular risk markers

Heart Health
Limited evidence

Higher total allium intake is associated with lower cardiovascular risk in observational studies, and most of the trial evidence in that family concerns garlic rather than leek. Nothing has tested leeks specifically against a cardiovascular outcome.

Limited evidence. Early human work, or mostly lab and animal research.

1 source

Deep research mode adds each paper’s own conclusion and stated limitations.

Gut microbiome

Gut & Digestive Health
Limited evidence

Leeks supply inulin-type fructans, and isolated fructans increase bifidobacteria in human trials. The dose from a normal portion of leek is well below what those trials used, and no study has fed leeks and sequenced the microbiome.

Limited evidence. Early human work, or mostly lab and animal research.

2 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Ask about Leek

Ask about Leek

Answers are written only from the entries on this page — the same nutrients, compounds, claims and citations you can read above. Nothing is added from outside the database, and every answer lists what it was built from.

AI explanations are not switched on for this site, so there is nothing to ask here. Everything above is read straight from the database and does not need them.

Key nutrients

Nutrient content per 100 grams
NutrientAmount% DV
Macronutrients
Calories61 kcal3%
Protein1.5 g3%
Total fat0.3 g0%
Carbohydrate14.2 g5%
Fibre1.8 g6%
Total sugars3.9 g—
Water83 g—
Fats
Saturated fat0.04 g0%
Monounsaturated fat0.0040 g—
Polyunsaturated fat0.166 g—
Cholesterol0 mg0%
EPA (omega-3)0 g—
DHA (omega-3)0 g—
DPA (omega-3)0 g—
Linoleic acid (omega-6)0.067 g—
Vitamins
Vitamin A83 µg9%
Vitamin C12 mg13%
Vitamin D0 µg0%
Vitamin E0.92 mg6%
Vitamin K47 µg39%
Thiamin (B1)0.06 mg5%
Riboflavin (B2)0.03 mg2%
Niacin (B3)0.4 mg3%
Pantothenic acid (B5)0.14 mg3%
Vitamin B60.233 mg14%
Folate64 µg16%
Vitamin B120 µg0%
Choline9.5 mg2%
Minerals
Calcium59 mg5%
Iron2.1 mg12%
Magnesium28 mg7%
Phosphorus35 mg3%
Potassium180 mg4%
Sodium20 mg1%
Zinc0.12 mg1%
Copper0.12 mg13%
Manganese0.481 mg21%
Selenium1 µg2%
Other measured compounds
Beta-carotene1000 µg—
Alpha-carotene0 µg—
Lycopene0 µg—
Lutein + zeaxanthin1900 µg—
Caffeine0 mg—
Ash1.05 g—

Nutrient values are per 100 g of the USDA reference entry named on this page and vary with variety, growing conditions, storage and preparation.

Source record: Leeks, (bulb and lower leaf-portion), raw (USDA FoodData Central, FDC ID 169246).

% DV uses the FDA Daily Values for adults and children aged 4 and over. A dash means no Daily Value has been established for that nutrient.

Bioactive compounds

Compounds present in meaningful amounts. Presence is banded rather than quantified, because whole-food levels vary enormously with variety, growing conditions, storage and preparation.

How preparation changes things

Only effects with real support are listed. If a preparation method is missing, it is because nothing dependable is documented — not because it makes no difference.

Nothing dependable is recorded about how preparation changes this food’s nutritional properties. Rather than guess, this section stays empty.

Things to know

Allergies, interactions and intake concerns. Every food gets this section — a reference where everything is uniformly good is not a reference.

  • Too much

    Fructans and irritable bowel syndrome

    Leeks are among the highest-fructan vegetables and a frequent hidden trigger in stocks, soups and sauces. The green leaf tops are much lower in fructans than the white part, which is the usual workaround on a low-FODMAP diet.

  • Allergy

    Allium allergy

    Genuine allergy to alliums is uncommon but documented, with reactions ranging from contact dermatitis in cooks to oral symptoms. People reacting to onion or garlic often react to leek as well.

  • Worth knowing

    Grit between the layers

    Soil is trapped between the leaf sheaths as the plant is earthed up. Leeks need splitting and washing thoroughly rather than a rinse, which is a practical matter rather than a health one.