Meridian Medica

01

Identity

Botanical Profile

Allium cepa L. — Bulb (fresh and cooked), outer skins (quercetin-rich). Native to Central Asia (Iran/Afghanistan region); cultivated worldwide for over 5,000 years; one of the oldest cultivated vegetables

Bulb: pungent, sulfurous, and lachrymatory when raw; sweet, rich, and caramelized when cooked. Red onions have a slightly more astringent, tannic character. Outer papery skins are odorless but rich in quercetin. Aroma intensifies with cutting or crushing (enzymatic allicin release).

Species Integrity

Allium cepa varieties differ significantly in quercetin and organosulfur content. Red and yellow onions contain substantially more quercetin than white varieties. The outer dry skins contain the highest concentration of quercetin (up to 10x the flesh).

02

Compounds

Active Compound Profile

Quercetin

200–600 mg/kg in flesh; 2,000–6,500 mg/kg in outer skins

Mast cell stabilizer; NF-κB inhibitor; antioxidant; inhibits CYP3A4 and P-glycoprotein; anti-histamine activity; thyroid peroxidase modulation

Allyl sulfides (diallyl disulfide, allyl propyl disulfide)

Variable; released enzymatically when cut/crushed

Phase II enzyme induction (glutathione S-transferase); antimicrobial; anti-inflammatory; NF-κB inhibition

Fructooligosaccharides (FOS/inulin)

2–6% fresh weight

Prebiotic; selectively feeds Bifidobacteria and Lactobacillus; SCFA production (butyrate) supports gut barrier integrity

S-alk(en)yl-L-cysteine sulfoxides

1–5% fresh weight

Precursors to lachrymatory factor and bioactive thiosulfinates; anti-diabetic activity; lipid-lowering effects

Absorption

Fat co-administration for quercetin: Quercetin is lipophilic; fat increases micellar solubilization and intestinal absorption by 2–3x

03

Pathways

Mechanism of Action

★★★☆☆ Quercetin / Mast Cell Stabilization Quercetin inhibits mast cell degranulation, reducing histamine release, tryptase secretion, and inflammatory cytokine production (IL-6, TNF-α)

★★★☆☆ NF-κB / Anti-Inflammatory Axis Both quercetin and organosulfur compounds inhibit NF-κB nuclear translocation via IKK-β inhibition, reducing COX-2, iNOS, and inflammatory cytokine expression

★★★☆☆ Phase II Detoxification Induction Organosulfur compounds (diallyl disulfide) induce glutathione S-transferase and other Phase II enzymes via Nrf2 activation, enhancing hepatic and systemic detoxification capacity

★★★☆☆ Prebiotic / Gut Microbiome Axis FOS/inulin selectively feed beneficial Bifidobacteria and Lactobacillus; microbial fermentation produces butyrate, which strengthens tight junctions and reduces gut permeability

★★★☆☆ Glycemic Regulation S-alk(en)yl-L-cysteine sulfoxides and quercetin improve insulin sensitivity via AMPK activation and GLUT4 translocation

04

Biomarkers

What It Moves in Your Labs

Biomarker	Direction	Target	Mechanism
hs-CRP	↓ Decrease	<1.0 mg/L	Quercetin and organosulfur NF-κB inhibition reduces systemic inflammatory marker production
Histamine (plasma or urine)	↓ Decrease	Normal range	Quercetin mast cell stabilization reduces histamine release; relevant for histamine intolerance common in Hashimoto's
Fasting Glucose	↓ Decrease	<100 mg/dL	Sulfoxide-mediated insulin potentiation and AMPK activation improve glycemic control
TPO Antibodies	↓ Decrease	<35 IU/mL	Indirect: multi-pathway anti-inflammatory support; gut barrier improvement via prebiotic FOS; reduced immune activation

05

Extraction

Extraction & Preparation

Raw (chopped/sliced): 100% all compounds; maximum sulfur compound release

Solubility · Aglycone is poorly water-soluble; glucosides are moderately water-soluble; both soluble in ethanolMenstruum · 50% ethanol / 50% waterPlant material · Fresh onion bulb (red preferred), chopped; include some outer skinsMaceration time · 2–4 weeks (agitate daily)Ratio · 1:2 (fresh)

07

Dosing

Dosing Framework

Onion can be consumed at any meal; no timing restrictions relative to thyroid medication beyond standard 30-min separation.

Dose 1

Culinary: 1/2 medium onion daily (75–100g)

Minimum effective culinary amount; easily achieved by including onion in one meal daily

Dose 2

Therapeutic: 1 whole medium onion daily (150–200g)

Incorporate into multiple meals; sauté in fat for quercetin absorption

Dose 3

Onion skin broth: 1–2 cups daily

Make weekly batch from saved skins; sip warm as daily tonic or use as soup base

08

Synergies

Synergy Partners

★★★☆☆ Garlic (Allium sativum) Synergistic organosulfur compound spectrum; garlic provides allicin while onion provides allyl propyl disulfide. Combined Phase II enzyme induction is greater than either alone.

★★★☆☆ Turmeric (Curcuma longa) Quercetin + curcumin provide complementary NF-κB inhibition through different binding mechanisms; both are enhanced by piperine

★★★☆☆ Black Pepper (Piper nigrum) Piperine enhances quercetin absorption by inhibiting Phase II metabolism and increasing intestinal permeability to flavonoids

★★★☆☆ Nettle (Urtica dioica) Nettle's natural antihistamine activity complements quercetin's mast cell stabilization; synergistic histamine management

★★★☆☆ Apple Cider Vinegar ACV acid environment enhances mineral extraction from bones and onion; prebiotic synergy with onion FOS

Signature Stack

THE ALLIUM FOUNDATION
Components: Onion (bulb) + Garlic (bulb) + Leek (leaf/stem) + Chive (leaf) · Multi-pathway convergence: Quercetin mast cell stabilization (onion) + Allicin antimicrobial/NF-κB inhibition (garlic) + Prebiotic FOS (onion + leek) + Phase II detox induction (all four alliums) · The Allium Foundation represents the oldest and most universal culinary medicine tradition on Earth. Every major cuisine uses allium family members as foundational aromatics because humans intuitively discovered their health-promoting properties through millennia of use. · Practical integration: Use onion and garlic as the base for all savory cooking. Add leeks to soups and stews. Use chives as a raw finishing herb. The combined allium intake should be a non-negotiable daily dietary habit.

09

Safety

Contraindications & Interactions

Minor FODMAP sensitivity / IBS Onion is high in fructans (a FODMAP) and is one of the most common triggers for IBS symptoms including bloating, gas, and abdominal pain. Fructans are water-soluble and leach into cooking water.

Minor Blood-thinning interaction Onion organosulfur compounds have mild antiplatelet activity. High-dose raw onion consumption may potentiate anticoagulant medications.

Minor Contact dermatitis / eye irritation Lachrymatory factor (syn-propanethial-S-oxide) causes tearing. Some individuals develop contact dermatitis from handling raw onion.

Avoid Pregnancy / Lactation Onion is safe as food during pregnancy and lactation. High-dose supplemental onion extracts lack specific safety data but food-level consumption is universal and traditional.

Minor Gastroesophageal reflux (GERD) Raw onion is a common GERD trigger; cooked onion is generally better tolerated. Onion relaxes the lower esophageal sphincter in susceptible individuals.

11

Evidence

Evidence Base

★★★★☆ Quercetin Anti-Inflammatory / Mast Cell Stabilization Strong — Extensive in vitro, animal, and human trial evidence for quercetin

★★★★☆ Prebiotic / Gut Microbiome Modulation Strong — Consistent human feeding study data

★★★☆☆ Glycemic Regulation Moderate — Small RCTs with consistent direction; mechanism characterized

★★☆☆☆ Bone Density Support Preliminary — Epidemiological associations; limited intervention data

★★★☆☆ Cardiovascular Protection Moderate — Consistent epidemiological data; quercetin trials support mechanism

Evidence Gaps

The highest-value research gap for Meridian Medica: no published study has examined onion-derived quercetin specifically for mast cell stabilization in Hashimoto's thyroiditis. Given the emerging evidence for mast cell involvement in autoimmune thyroid disease and quercetin's well-documented mast cell stabilizing properties, an RCT evaluating daily onion consumption (or onion skin quercetin extract) alongside TPO antibody levels, serum tryptase, and histamine metabolites in Hashimoto's patients would directly test this pathway.

Quality Alert

Onion adulteration risk is minimal for whole fresh bulbs — it is what it is. Risks apply primarily to processed forms:

12

Protocol

Protocol Integration

Layer 1: Hypothalamic / Autonomic — HPA axis, circadian rhythm, stress response

Layer 2: Systemic Nutritional Repletion — Micronutrient optimization, antioxidant defense

Layer 3: Gut Permeability / Microbiome — Tight junction repair, motility, SIBO management

Recipe Integration

Quercetin Bone Broth (signature preparation)

3 whole onions with skins per batch; 1–2 cups broth daily

Feed the Markers

Onion appears in the following Meridian Medica protocol contexts: