Dry-Roasted vs Raw Peanuts: Which Causes A Worse Allergic Reaction?

Dry-roasted peanuts are more likely to cause allergic reactions than raw peanuts, according to a new study.

Researchers already knew that exposure to high temperatures (160° to 170°) during the roasting process changed the peanut protein, but the new findings indicate that the specific change triggers an allergic immune response the next time the body sees any peanuts.

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This may help to explain why in the Western world, where dry roasted peanuts are more common, there are far more people have peanut allergies than in the East, where peanuts are traditionally boiled, fried, or eaten raw.

In order to better understand the different immune responses, researchers purified proteins from dry roasted and raw peanuts and exposed mice to the proteins in 3 ways: under the skin, onto broken skin, and in the stomach.

Immune responses were significantly more common in mice exposed to dry-roasted peanuts than those exposed to raw peanuts.

“Our results in mice suggest that dry roasted peanuts may be more likely to lead to peanut allergy than raw peanuts: the dry roasting causes a chemical modification of peanut proteins that appears to activate the immune system against future exposure to peanuts,” researchers concluded.  

—Michael Potts


Moghaddam AE, Hillson WR, Noti M, et al. Dry roasting enhances peanut-induced allergic sensitization across mucosal and cutaneous routes in mice. J Allergy Clin Immunol. 2014 Sep 21 [epub ahead of print] doi:

University of Oxford. Dry roasting could help trigger peanut allergy [press release]. September 21 2014. Accessed September 22, 2014.