# Leeks (Allium ampeloprasum)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/leeks
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-31
**Evidence Score:** 2 / 10
**Category:** Vegetable
**Also Known As:** Wild leek, Broadleaf wild leek, Elephant garlic, Great-headed garlic, Levant garlic, Pearl onion, Kurrat, Lebanese wild leek

## Overview

Leeks (Allium ampeloprasum) contain organosulfur compounds and tocotrienols that provide antioxidant activity through [free radical scaveng](/ingredients/condition/antioxidant)ing mechanisms. The seed oil demonstrates particularly high concentrations of γ-tocotrienol (79.56 mg/100g) and δ-tocotrienol (52.08 mg/100g).

## Health Benefits

• [Antioxidant activity](/ingredients/condition/antioxidant) demonstrated through in vitro DPPH and ABTS radical scavenging assays (preliminary evidence only)
• Oxidative stability properties from seed oil containing tocotrienols (γ- and δ- forms at 79.56 and 52.08 mg/100 g oil) (in vitro evidence)
• Source of organosulfur compounds including S-alkyl-cysteine sulphoxides with potential health-promoting properties (traditional use, no clinical evidence)
• Rich in phenolics (up to 35.50 mg GAE/g DW in leaves) and flavonoids with metal chelation capacity (in vitro evidence only)
• Contains essential fatty acids including linoleic acid (71.65% in seed oil) (compositional data only)

## Mechanism of Action

Leeks' organosulfur compounds neutralize DPPH and ABTS free radicals through electron donation mechanisms. The tocotrienols (γ- and δ- forms) in leek seed oil protect against lipid peroxidation by breaking radical chain reactions in cellular membranes. These vitamin E analogs demonstrate superior [antioxidant activity](/ingredients/condition/antioxidant) compared to traditional tocopherols in oxidative stability assays.

## Clinical Summary

Current evidence for leeks is limited to preliminary in vitro studies demonstrating [antioxidant](/ingredients/condition/antioxidant) capacity through DPPH and ABTS radical scavenging assays. Research has identified significant tocotrienol content in leek seed oil, with γ-tocotrienol at 79.56 mg/100g and δ-tocotrienol at 52.08 mg/100g. No human clinical trials have been conducted to evaluate therapeutic efficacy. The existing evidence represents early-stage laboratory research requiring validation in human studies.

## Nutritional Profile

Leeks (Allium ampeloprasum) per 100g raw edible portion: Macronutrients - Energy ~61 kcal, Carbohydrates ~14.2g (including ~1.8g dietary fiber, primarily fructooligosaccharides and inulin-type fructans acting as [prebiotic](/ingredients/condition/gut-health)s), Protein ~1.5g (containing sulfur-containing amino acids including S-allyl-cysteine sulphoxide/alliin ~0.5-1.0mg/g fresh weight), Fat ~0.3g. Key Micronutrients - Vitamin K1 (phylloquinone): ~47mcg (39% DV, high bioavailability when consumed with dietary fat), Folate (B9): ~64mcg (16% DV, as polyglutamate forms requiring intestinal deconjugation before absorption), Vitamin C: ~12mg (13% DV, heat-labile, reduced by cooking), Vitamin A (as carotenoids): ~83mcg RAE primarily from lutein and beta-carotene in green portions, Manganese: ~0.36mg (16% DV), Iron: ~2.1mg (non-heme form, bioavailability enhanced by co-consumed vitamin C), Copper: ~0.12mg, Calcium: ~59mg (bioavailability moderately reduced by oxalate content). Bioactive Compounds - Organosulfur compounds: S-alk(en)yl-cysteine sulphoxides including S-propyl-cysteine sulphoxide and S-propenyl-cysteine sulphoxide as primary forms (distinct from garlic's alliin dominance); Flavonoids: Kaempferol glycosides (~0.5-3.0mg/100g, concentrated in outer green leaves) and quercetin at lower concentrations than onion; Polyphenols: total phenolic content approximately 30-60mg gallic acid equivalents/100g fresh weight (higher in outer leaves); Carotenoids: lutein and zeaxanthin ~1mg/100g (concentrated in dark green portions, fat-soluble, bioavailability improved with lipid co-ingestion); Chlorophyll a and b present in green leaf portions. Seed oil composition (not culinary use): tocotrienols including γ-tocotrienol at 79.56mg/100g oil and δ-tocotrienol at 52.08mg/100g oil as documented. Bioavailability Notes - Organosulfur compounds released upon cell damage (chopping/chewing) via alliinase enzyme activity; cooking deactivates alliinase reducing bioactive sulfur compound yield; inulin-type fructans resist upper GI digestion reaching colon intact for fermentation; vitamin K and carotenoid absorption significantly enhanced by co-consumption with fats; iron absorption estimated at 5-12% (non-heme) dependent on meal composition.

## Dosage & Preparation

No clinically studied dosage ranges are available as human trials are absent. Traditional dietary consumption involves the whole vegetable in culinary preparations. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Leeks are generally recognized as safe when consumed as food, with no known serious adverse effects in healthy individuals. Some people may experience digestive upset, gas, or bloating due to the oligosaccharide content. Individuals taking anticoagulant medications should exercise caution as organosulfur compounds may theoretically enhance bleeding risk. Pregnancy and breastfeeding safety data is limited, though culinary use appears safe.

## Scientific Research

No human clinical trials, RCTs, or meta-analyses specific to Allium ampeloprasum (leeks) were identified. Research is limited to in vitro [antioxidant](/ingredients/condition/antioxidant) assays showing radical scavenging activity correlated with phenolic and flavonoid content, without any PubMed PMIDs for clinical outcomes available.

## Historical & Cultural Context

Allium ampeloprasum has been cultivated for centuries as an edible wild leek with ethnopharmacological use in Tunisia for its bioactive compounds. Traditional culinary and potential medicinal roles in regional diets are suggested by its characteristic flavor from S-alkyl-cysteine sulphoxides.

## Synergistic Combinations

Garlic, Onion, Vitamin E, Selenium, Quercetin

## Frequently Asked Questions

### What compounds in leeks provide health benefits?

Leeks contain organosulfur compounds and high concentrations of tocotrienols, particularly γ-tocotrienol (79.56 mg/100g oil) and δ-tocotrienol (52.08 mg/100g oil). These compounds demonstrate antioxidant activity through free radical scavenging mechanisms.

### How do leeks compare to other allium vegetables?

Leeks (Allium ampeloprasum) belong to the same family as garlic and onions but have distinct phytochemical profiles. While sharing organosulfur compounds with other alliums, leek seed oil shows particularly high tocotrienol content compared to other members of the allium family.

### Are there any proven health benefits of leeks?

Current evidence is limited to laboratory studies showing antioxidant activity through DPPH and ABTS radical scavenging assays. No human clinical trials have been conducted to prove therapeutic benefits, so health claims remain preliminary.

### Can leeks interact with blood thinning medications?

Theoretically, leeks' organosulfur compounds could enhance anticoagulant effects of blood thinning medications, potentially increasing bleeding risk. However, no specific drug interactions have been documented in clinical studies.

### What is the difference between leek bulb and seed oil?

Leek seed oil contains concentrated tocotrienols (γ- and δ- forms totaling over 130 mg/100g oil) while the bulb provides organosulfur compounds. The seed oil demonstrates superior oxidative stability properties compared to the commonly consumed bulb portion.

### What is the research quality and strength of evidence for leek health benefits?

Most leek research consists of in vitro studies (test-tube assays) demonstrating antioxidant activity through DPPH and ABTS radical scavenging, which provides preliminary evidence only and does not confirm human health effects. Clinical trials in humans are limited, meaning many traditional health claims lack robust scientific validation. The organosulfur compounds in leeks show theoretical promise based on their chemical properties, but evidence-based recommendations require controlled human studies that are currently insufficient.

### Can I get enough leek compounds from whole food sources instead of supplements?

Yes—leeks are USDA nutrient-dense foods and eating whole leeks provides the complete matrix of organosulfur compounds, vitamins, and minerals in their natural form. Whole leeks contain S-alkyl-cysteine sulphoxides and other bioactive compounds without the processing required for supplements or isolated oils. Since clinical evidence for supplemental leek extracts remains limited, consuming leeks as food is a well-established approach to obtain their nutritional profile.

### Is leek seed oil more effective than whole leek consumption for antioxidant benefits?

Leek seed oil contains concentrated tocotrienols (γ- and δ- forms) that demonstrate oxidative stability in vitro, but direct human comparisons between seed oil and whole leeks are not available. While seed oil provides isolated compounds, whole leeks offer a broader spectrum of nutrients and compounds that may work synergistically. Without clinical evidence comparing efficacy in humans, whole leek consumption remains the evidence-based approach to obtaining leek's nutritional benefits.

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*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
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