Onion (Allium cepa L.)

About

What it is and where it shows up.

Onion (Allium cepa L.) is a widely consumed bulb vegetable used globally as a whole food ingredient prized for its pungent flavor, aroma, and nutritional value. It is rich in bioactive phytochemicals—including organosulfur compounds, quercetin glucosides, flavonoids, and polysaccharides—that underlie both its culinary and health-promoting properties.

Safety summary

The regulatory and scientific consensus.

Onions are broadly recognized as safe for human consumption across all major food regulatory authorities with no established ADI, as they are whole foods rather than additives. Accumulated scientific evidence supports antioxidant, anti-inflammatory, antihypertensive, anti-obesity, and anti-diabetic effects attributable to quercetin and organosulfur compounds. Individuals with IBS may experience significant digestive discomfort due to high fructan (FODMAP) content, and those on anticoagulant or antiplatelet therapies should exercise caution due to documented antiplatelet activity.

Regulatory landscape

What food-safety regulators have decided.

Jurisdiction	Status	Note
FSANZ (Food Standards Australia New Zealand) (Australia)	Approved	Onions are freely sold as whole food vegetables under the Australia New Zealand Food Standards Code. No specific additive classification, E number, or usage restriction applies to the raw vegetable.source
EFSA (European Food Safety Authority) (European Union)	Approved	Onions are freely marketed as whole vegetables across all EU member states under Regulation (EC) No 178/2002 (General Food Law). No specific EFSA safety opinion or maximum usage limit is required for whole food vegetables.source
FSSAI (Food Safety and Standards Authority of India) (India)	Approved	Onions are recognized as a standard food item under the Food Safety and Standards Act, 2006 and FSS Regulations notified in the Gazette of India on 1 August 2011. Freely sold as fresh vegetables with no maximum intake restrictions. Onion and vegetable extracts may be used in nutraceuticals per FSSAI (Health Supplements & Nutraceuticals) Regulations, 2016 with prior approval for specific health claims.source
FDA (Food and Drug Administration) (United States)	Approved	Onions are a whole food vegetable with a centuries-long history of safe human consumption; they do not require a GRAS notification or food-additive approval and are freely sold as fresh produce under FDA jurisdiction. No usage-level restrictions exist.source

Who should approach with care

Whose guidance would steer them away.

Ibs — Onions are very high in fructans—a poorly absorbed, fermentable FODMAP—which can trigger bloating, gas, cramping, and altered bowel habits in individuals with irritable bowel syndrome.

Ibd — Raw onions may irritate the gut lining and exacerbate symptoms during active flares of inflammatory bowel disease (Crohn's disease or ulcerative colitis); well-cooked onion is generally better tolerated.

Heart Disease — Onions possess documented antiplatelet and antithrombotic activity; patients on anticoagulant or antiplatelet medications (e.g., warfarin, aspirin, clopidogrel) should consult their physician before consuming high-dose onion supplements or extracts.

Infants — Raw or large quantities of onion are inappropriate for very young infants due to potential digestive intolerance and strong bioactive content; small amounts of cooked, pureed onion are typically introduced gradually after 6 months of age.

Migraine — Onions contain biogenic amines and sulfur compounds that are recognized dietary triggers for migraine headaches in susceptible individuals, and elimination diets for migraine frequently include onion restriction.

Research citations

The sources behind this verdict.

1PubMed. Antiobesity effects of onion (Allium cepa) in subjects with obesity: Systematic review and meta-analysis, 2023. pubmed.ncbi.nlm.nih.gov
2PubMed. Recent Advances in Bioactive Compounds, Health Functions, and Safety Concerns of Onion (Allium cepa L.), 2021. pubmed.ncbi.nlm.nih.gov
3PubMed. A review of anti-inflammatory, antioxidant, and immunomodulatory effects of Allium cepa and its main constituents, 2021. pmc.ncbi.nlm.nih.gov
4PubMed. The effects of Allium cepa L. (onion) and its active constituents on metabolic syndrome: A review, 2021. pmc.ncbi.nlm.nih.gov
5PubMed. Onions—a global benefit to health, 2002. pubmed.ncbi.nlm.nih.gov

Independently researched5 citations