Onion / Red Onion
Allium cepa
Quercetin and fisetin from onion — particularly red onions — are among the most studied flavonoid anti-cancer compounds. Quercetin inhibits cancer cell proliferation across multiple cancer types, reduces angiogenesis, and has strong synergy with conventional chemotherapy drugs. Onion's organosulfur compounds (similar to garlic) additionally suppress carcinogen activation.
Medicinal Properties
Cancer Types Studied
Recommended Dosage
1 medium red onion daily in food, or 500–1000 mg quercetin supplement.
Preparations
Raw Red Onion
Eat half a raw red onion daily in salads — cooking reduces quercetin. Chopping and letting sit 10 min activates alliinase.
Quercetin Supplement
500–1000 mg quercetin phytosome (better absorbed) daily with food.
NIH / PubMed Research
Links open on PubMed (National Library of Medicine). Research is ongoing — results may not reflect clinical use.
Cautions & Interactions
- Raw onion may irritate gut in sensitive individuals — cook if needed
- May interact with blood-thinning medications at supplement doses
- May lower blood sugar
- Generally very safe at food amounts — one of the safest cancer-protective foods
Related Herbs
Informational only. Not medical advice. Consult your healthcare provider before use.