# Scallion (Allium fistulosum)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/scallion
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-24
**Evidence Score:** 2 / 10
**Category:** Vegetable
**Also Known As:** Allium fistulosum, Welsh onion, Spring onion, Green onion, Bunching onion, Japanese bunching onion, Negi, Cong

## Overview

Scallion (Allium fistulosum) contains bioactive compounds including flavonoids, vitamin C, and organosulfur compounds that demonstrate anti-inflammatory and [antioxidant](/ingredients/condition/antioxidant) properties. The primary mechanisms involve modulation of IL-10/CD163 and IFN-γ/iNOS [inflammatory pathway](/ingredients/condition/inflammation)s.

## Health Benefits

• [Anti-inflammatory](/ingredients/condition/inflammation) effects demonstrated through modulation of IL-10/CD163 and IFN-γ/iNOS pathways (in vitro evidence only)
• [Antioxidant activity](/ingredients/condition/antioxidant) from flavonoids (465.87 mg/g), vitamin C (0.161 mg/g), and carotenoids (2.87 mg/g) in leaf extracts (in vitro studies)
• Antimicrobial properties attributed to allicin and polysulfides formed upon tissue damage (in vitro evidence)
• Potential anti-obesity effects reported in animal studies (preliminary evidence)
• [Immunomodulatory](/ingredients/condition/immune-support) activity with Onionin A1 inhibiting IL-10-induced CD163 expression in cell lines (in vitro only)

## Mechanism of Action

Scallion's bioactive compounds modulate inflammatory responses through the IL-10/CD163 anti-[inflammatory pathway](/ingredients/condition/inflammation) while suppressing IFN-γ/iNOS pro-inflammatory signaling. The flavonoids (465.87 mg/g) and vitamin C (0.161 mg/g) in leaf extracts provide [antioxidant protection](/ingredients/condition/antioxidant) by scavenging free radicals. Organosulfur compounds contribute to [antimicrobial](/ingredients/condition/immune-support) activity through cell membrane disruption mechanisms.

## Clinical Summary

Current evidence for scallion's health benefits comes primarily from in vitro laboratory studies rather than human clinical trials. Research has quantified specific bioactive compound concentrations including 465.87 mg/g flavonoids, 0.161 mg/g vitamin C, and 2.87 mg/g carotenoids in leaf extracts. The [anti-inflammatory](/ingredients/condition/inflammation) and [antimicrobial](/ingredients/condition/immune-support) properties demonstrated in cell culture studies require validation through controlled human studies. No large-scale clinical trials have been conducted to establish therapeutic dosages or clinical efficacy.

## Nutritional Profile

Per 100 g raw scallion (green onion, Allium fistulosum): Energy ~32 kcal; Water ~89.8 g; Protein ~1.83 g; Total fat ~0.19 g; Carbohydrates ~7.34 g (including ~2.33 g sugars, primarily fructose and glucose); Dietary fiber ~2.6 g (mix of soluble fructans/inulin-type fructooligosaccharides and insoluble cellulose/hemicellulose). VITAMINS: Vitamin K1 (phylloquinone) ~207 µg (173% DV, high bioavailability from lipid-soluble matrix when consumed with fat); Vitamin C (ascorbic acid) ~18.8 mg (21% DV, degrades significantly with cooking — ~30–50% loss upon boiling); Folate (B9) ~64 µg (16% DV); Vitamin A as provitamin A carotenoids (primarily β-carotene ~598 µg, equivalent to ~997 IU; bioavailability enhanced by fat co-ingestion and thermal processing); Riboflavin (B2) ~0.08 mg; Thiamine (B1) ~0.055 mg; Vitamin B6 (pyridoxine) ~0.061 mg; Vitamin E (α-tocopherol) ~0.55 mg; Niacin ~0.525 mg. MINERALS: Potassium ~276 mg; Calcium ~72 mg (moderate bioavailability ~20–30%, partially limited by oxalate content); Iron ~1.48 mg (non-heme form, bioavailability ~5–12%, enhanced by concurrent vitamin C intake); Manganese ~0.16 mg; Magnesium ~20 mg; Phosphorus ~37 mg; Zinc ~0.39 mg; Copper ~0.083 mg; Selenium ~0.6 µg. BIOACTIVE COMPOUNDS: Organosulfur compounds — alliin (S-allyl-L-cysteine sulfoxide) converted to allicin and further to diallyl disulfide (DADS), diallyl trisulfide (DATS), and methyl allyl disulfide upon tissue disruption by alliinase enzyme (estimated total thiosulfinates ~0.5–1.5 mg/g fresh weight in green leaves, higher ~2–5 mg/g in white bulb portion); Flavonoids — quercetin (primarily as quercetin-3,4'-diglucoside and quercetin-4'-glucoside, total quercetin glycosides ~10–50 mg/100 g in green leaves; bioavailability of glucoside forms is relatively high at ~50% absorption compared to aglycone); kaempferol glycosides present in lower concentrations (~2–10 mg/100 g); Phenolic acids — ferulic acid, caffeic acid, and p-coumaric acid (~5–20 mg GAE/100 g total phenolics); Fructooligosaccharides (FOS)/inulin-type fructans ~0.5–1.5 g/100 g ([prebiotic](/ingredients/condition/gut-health) activity, resistant to upper GI digestion, fermented by colonic Bifidobacterium and Lactobacillus spp. producing short-chain fatty acids); Carotenoids — lutein + zeaxanthin ~1137 µg/100 g (bioavailability improved with dietary fat; relevant to macular health); Chlorophyll present in green portions (~15–30 mg/100 g); Saponins — trace to low levels in bulb tissue; Pectin and arabinogalactans contributing to soluble fiber fraction. NOTE: Green leaf portions are significantly richer in vitamins A, C, K, and flavonoids compared to the white sheath/bulb portion, which is richer in organosulfur compounds and fructans. Nutrient density is high relative to caloric content, making scallions a micronutrient-dense low-calorie food.

## Dosage & Preparation

No clinically studied dosage ranges are reported for extracts, powders, or standardized forms of Allium fistulosum. Studies do not specify standardization levels used. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Scallion is generally recognized as safe when consumed as food, with minimal reported adverse effects in healthy individuals. Individuals with allium allergies may experience allergic reactions including skin irritation or digestive upset. No significant drug interactions have been documented, though individuals taking anticoagulant medications should monitor intake due to potential vitamin K content. Safety during pregnancy and lactation is presumed safe at food levels, but therapeutic doses have not been studied in these populations.

## Scientific Research

No human clinical trials, RCTs, or meta-analyses on Allium fistulosum were found in the available research. Evidence is limited to in vitro and animal studies showing anti-obesity, anti-viral, antimicrobial, anti-tumor, anti-oxidant, [anti-inflammatory](/ingredients/condition/inflammation), and [immunomodulatory](/ingredients/condition/immune-support) effects.

## Historical & Cultural Context

Allium fistulosum has been used as an important spice worldwide with implied historical roles in traditional medicine due to its phytochemicals. Pharmacological evidence builds on its long-standing use for potential anti-obesity, anti-viral, and [anti-inflammatory](/ingredients/condition/inflammation) benefits, though specific traditional medicine systems or indications are not detailed.

## Synergistic Combinations

Garlic, Turmeric, Ginger, Quercetin, Vitamin C

## Frequently Asked Questions

### What are the main active compounds in scallion?

Scallion contains flavonoids (465.87 mg/g), vitamin C (0.161 mg/g), carotenoids (2.87 mg/g), and organosulfur compounds. These bioactive compounds are responsible for the anti-inflammatory, antioxidant, and antimicrobial properties demonstrated in laboratory studies.

### How does scallion reduce inflammation?

Scallion modulates inflammation through the IL-10/CD163 anti-inflammatory pathway while suppressing pro-inflammatory IFN-γ/iNOS signaling. This dual action helps balance immune responses, though evidence comes from in vitro studies only.

### Is there clinical evidence for scallion health benefits?

Current evidence for scallion's health benefits comes primarily from laboratory studies rather than human clinical trials. While in vitro research shows promising anti-inflammatory and antioxidant effects, controlled human studies are needed to confirm therapeutic benefits.

### What is the difference between scallion and green onion?

Scallion (Allium fistulosum) and green onion are often used interchangeably, though scallions technically refer to young onions harvested before bulb formation. Both contain similar bioactive compounds including flavonoids and organosulfur compounds with comparable health-promoting properties.

### Are there any side effects from eating scallions?

Scallions are generally safe when consumed as food, with minimal side effects in healthy individuals. People with allium allergies may experience digestive upset or skin reactions, and those taking blood-thinning medications should monitor intake due to potential nutrient interactions.

### Can I get sufficient antioxidants from eating scallions regularly, or do I need a supplement?

Scallions provide meaningful antioxidants including flavonoids, vitamin C, and carotenoids that contribute to overall dietary antioxidant intake. However, the bioavailable amounts depend on preparation method—raw scallions retain more heat-sensitive vitamin C than cooked varieties. For therapeutic antioxidant doses demonstrated in research studies, supplemental extracts typically concentrate these compounds far beyond what fresh scallions alone provide, though whole food consumption still offers nutritional value as part of a balanced diet.

### Is scallion safe for pregnant women or nursing mothers?

Scallions are generally recognized as safe food by the USDA and are commonly consumed during pregnancy and lactation in many cuisines without documented adverse effects. However, high-dose scallion supplements or extracts have not been formally studied in pregnant or nursing populations, so whole food consumption is preferred during these periods. Pregnant women should consult their healthcare provider before using concentrated scallion supplements, as safety data in this population is limited.

### How does cooking or processing scallions affect their antimicrobial and antioxidant properties?

Raw scallions generate antimicrobial allicin and polysulfides when cells are damaged through cutting or chewing, making fresh preparations potentially more antimicrobially active than cooked forms. Heat exposure significantly reduces vitamin C content and may degrade some flavonoids, though certain carotenoids become more bioavailable after cooking. For maximum antimicrobial benefit, consume scallions raw or minimally processed; for overall antioxidant contribution, including both raw and cooked preparations in your diet provides complementary nutrient profiles.

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