Intended for healthcare professionals


Randomised, double blind, crossover challenge study of allergenicity of peanut oils in subjects allergic to peanuts

BMJ 1997; 314 doi: (Published 12 April 1997) Cite this as: BMJ 1997;314:1084
  1. Jonathan O'B Hourihane, clinical research fellowa,
  2. Simon J Bedwani, medical studenta,
  3. Taraneh P Dean, senior research fellowa,
  4. John O Warner, professora
  1. a University Department of Child Health Mailpoint 803 Southampton General Hospital Southampton SO16 6YD
  1. Correspondence and reprint requests to: Dr Hourihane
  • Accepted 24 January 1997


Objective: To determine the in vivo allergenicity of two grades of peanut oil for a large group of subjects with proved allergy to peanuts.

Design: Double blind, crossover food challenge with crude peanut oil and refined peanut oil.

Setting: Dedicated clinical investigation unit in a university hospital.

Subjects: 60 subjects allergic to peanuts; allergy was confirmed by challenge tests.

Outcome measures: Allergic reaction to the tested peanut oils

Results: None of the 60 subjects reacted to the refined oil; six (10%) reacted to the crude oil. Supervised peanut challenge caused considerably less severe reactions than subjects had reported previously.

Conclusions: Crude peanut oil caused allergic reactions in 10% of allergic subjects studied and should continue to be avoided. Refined peanut oil did not pose a risk to any of the subjects. It would be reasonable to recommend a change in labelling to distinguish refined from crude peanut oil.

Key messages

  • Peanut (groundnut) allergy is the most common cause of deaths related to food allergy. Peanut oil is often suspected of causing reactions to meals in which a more obvious source of peanut cannot be found

  • Refined peanut oil is odourless and flavourless and is commonly used in catering. Crude peanut oil, which is known to contain considerable amounts of protein is used only rarely, when a peanut flavour is deliberately required

  • In vivo challenges of 60 subjects with proved peanut allergy showed no reaction to refined peanut oil, but six (10%) reacted to the crude peanut oil

  • If refined peanut oil is used properly and is not reused after cooking peanuts, it seems to be safe for most people with peanut allergy; crude oil represents a risk

  • The confusing use of the term groundnut oil should be stopped, and food labelling should distinguish between refined and crude oils


    • Accepted 24 January 1997
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