- Mustard plants come from several plant species (genera Brassica and Sinapis). The most common types of mustard are Sinapis alba (also called Brassica alba, yellow mustard, or white mustard) and Brassica juncea (also called brown mustard or Indian mustard). Black mustard (Brassica nigra) fell out of use in commercial mustard products in the 1950s.
- Mustard has a long history of use. Traditionally, mustard or mustard oil have been used as a treatment for stomach and intestinal disorders and diabetes, as a natural antibacterial agent, to stimulate vomiting, and as a massage oil to improve blood circulation, muscular development, and skin texture. Mustard plaster (a mixture of flour and mustard powder) has been traditionally applied to the chest and abdomen to promote healing. Today, the primary use of mustard is as a condiment.
- The pungency of mustard comes from its isothiocyanate compounds. Mustard oil is a pungent plant extract from mustard seed, horseradish, and wasabi, and its main constituent is allyl isothiocyanate. Although it is used in India and elsewhere as a cooking oil, high doses injected or applied topically can cause irritation and inflammation.
- There is limited human evidence in support of the use of mustard plaster for bronchitis or for the use of mustard oil in prevention of heart attack. Evidence is conflicting as to whether mustard oil is effective at lowering cholesterol levels or as to its beneficial effects as a massage agent in infants. At this time, high-quality human trials in support of the use of mustard or mustard oil for any indication are limited. Better-designed clinical trials are needed before recommendations can be made regarding taking mustard for any condition.