Rape seed is a food which may result in allergy symptoms in sensitised individuals.

Rape Seed Allergy Test: Allergen Exposure

The rape plant is native to northern Europe and the Mediterranean regions, but is now an important global crop cultivated primarily for animal feed, bird seed and rape seed oil, which is widely used in cooking and commercial food production.

Canola is a selectively bred cultivar of rape which has lower levels of saturated fats and fatty acids than the original plant. Canola oil is also almost free of erucic acid, a toxic compound plentiful in older varieties. It is also a good source of vitamin E.

Rape is closely related to turnip and rutabaga, and it is thought that it originated from a hybrid between turnip and kale.

Rape seed oil is used cold as a salad dressing or heated for frying, roasting and baking. It has a high smoke point which makes it particularly suited to high temperature cooking methods such as deep fat frying. Due to its low saturated fat content it is often promoted as a healthier alternative to other vegetable and animal fats.

Rape Seed Allergy Test: Allergen Description

One key allergen present in rape seed has been characterised, an albumin.

Rape Seed Allergy Test: Potential Cross-Reactivity

An extensive cross-reactivity among the different individual species of the family could be expected to occur clinically with rape seed.

A study of children sensitised to rape seed reported that the high correlation in the skin reactivity between rape seed and turnip rape suggested cross-reactivity.

Rape Seed Allergy Test: Clinical Experience

Rape seed protein may induce symptoms of allergy in sensitised individuals, predominantly in occupational settings such as animal feed factories, grain mills and farms. Individuals may be sensitised to either Rape seed as a food or Rape seed pollen as an inhalant.

A 48-year-old man who had been working in a feed processing plant suffered episodes of wheezing with shortness of breath after exposure to rape seed flour. He also developed oedema and pruritis of the lips, oral mucosa and pharynx, and facial urticaria immediately after ingestion of a small amount of mustard sauce. This was attributed to cross reactivity with the albumins present in rape seed and mustard.

A 48-year-old man, employed in a grain and animal feed store for 9 years, reported rhinorrhea, sneezing, nasal obstruction, ocular burning, coughing and wheezing, induced by rape flour.

A 43-year-old male working in the grain industry, and having been exposed to rape seed dust, experienced cough and chest tightness during working hours.

Similarly, a study demonstrated that inhalation of rape flour caused bronchoconstriction, induced an eosinophilic inflammatory bronchial response, and increased bronchial hyperresponsiveness in sensitised asthmatic farmers. Contact with the allergen took place through its presence as flour in animal fodder.

Other reactions

Pure rape seed oil is reported not to cause allergic reactions. However, occupational allergic contact dermatitis from rape seed amide present in massage oil has been reported.