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White mustard

Sinapis alba

Also calledYellow mustard

The pale-seeded mustard of European cooking, whose crushed seeds have for centuries been used in warming, skin-reddening poultices and liniments and as a digestive aid. The best clinical evidence is recent and narrow: a mustard-extract toothpaste modestly reduced plaque and gum bleeding. The seed is also a recognised food allergen that can cause anaphylaxis, and poultices can blister the skin.

What it is used for

Mouth ulcers and gum health
Limited
In a double-blind randomised trial in 113 people with gingivitis, four weeks of a toothpaste containing S. alba extract reduced the plaque index by 2.43 points (placebo 1.95) and bleeding on probing by 30.6% (placebo 26.8%); a six-month follow-up with a low-erucic 'Bamberka' extract reported similar gains. Small effects in few trials.¹
Muscle pain and cramps
Traditional
Crushed or macerated seeds have for centuries been used in rubefacient poultices and warming liniments. No controlled trials of mustard poultices were found.¹
Indigestion and dyspepsia
Traditional
Traditionally used as a digestive aid; untested clinically.¹

How it is prepared

poultice

Crushed or macerated seeds applied to the skin as a warming, reddening poultice. Contact time matters: prolonged contact can cause irritation and blistering. No attributed dose was found.

Muscle pain and cramps

food

Seeds used whole, ground or as prepared mustard.

Amounts are as recorded by the named source, not a recommendation.

Safety

Pregnancy: Insufficient data
Breastfeeding: Insufficient data
Children: Mustard allergy often begins in early childhood (under 3 years in about half of allergic children in one French series), though reactions in children were usually not severe.

Do not use if

Mustard allergy, or cross-allergy to other cabbage-family plants or mugwort pollen
Broken or sensitive skin (for poultices)

Side effects

Skin irritation and blistering from poultices, depending on dose and contact time
Oral burning or mucosal irritation from mouth products
IgE-mediated allergy, including systemic anaphylaxis

Toxicity

Not toxic as a food in normal amounts. Mustard allergy is not rare: in one series of 38 mainly adult patients, 10.5% reported systemic anaphylaxis, and mustard allergy was associated with mugwort pollen allergy and with food-dependent exercise-induced anaphylaxis.

In the healing traditions

European folk medicine
White mustard
Crushed seeds in skin-reddening poultices and warming liniments, and as a digestive aid.

Active compounds

sinalbin: glucosinolate characteristic of white mustard; myrosinase converts it to p-hydroxybenzyl isothiocyanate
isothiocyanates: pungent, antimicrobial and skin-irritating hydrolysis products; responsible for blistering
Sin a 1, Sin a 2: seed storage proteins; Sin a 1 (a 2S albumin) is the major allergen
erucic acid: fatty acid of the seed oil; low in cultivars such as 'Bamberka' (<0.5%)

History

Crushed mustard seed has been used for centuries in Europe and Asia in warming poultices and liniments as well as in cooking. Recent research has instead focused on mustard-extract toothpastes for gum disease.

Sources

Reference, not prescription. Nothing here is medical advice. Herbs can interact with medicines and be dangerous in pregnancy; tell your doctor or pharmacist about anything you take.