Peanuts are in fact legumes, not nuts. Lupin is an easy-to-grow legume that contains three times more plant protein than quinoa, three times more fiber than oats, three times more antioxidants than berries, three times more potassium than bananas, and three times more iron than kale. As such, it is increasingly being used in packaged food products worldwide.
With that increase, reports of allergic reactions to lupin are also rising with some uncertainty as to the cross-reactivity between those diagnosed with peanut allergies and lupin. Researchers from Chile sought to determine that incidence and published their findings in the Annals of Allergy, Asthma & Immunology.
A total of 43 subjects with peanut allergy, lupin allergy, or controls without food allergy were evaluated with skin prick tests (SPTs) and specific IgEs (sIgEs). Lupin-sensitized subjects were offered a lupin oral food challenge (OFC). Immunoblots and enzyme-linked immunosorbent assays were performed on sera from lupin-sensitized subjects.
The researchers found that 44% of the peanut allergy subjects were confirmed to have lupin allergy by OFC. Anaphylaxis was the most frequent manifestation after lupin ingestion with a minimal eliciting dosage of 1g of lupin flour. No difference was found in the lupin sIgE or SPT wheal size between lupin-sensitized and confirmed LA subjects or in the severity of symptoms among confirmed LA subjects. Sera from lupin-sensitized subjects uniformly reacted to all 3 different lupin species.
They concluded that the prevalence of lupin allergy was high among subjects with peanut allergy and as a result, lupin should be labeled as an allergen in foods. Although lupin is required to be labeled as such in the EU, it is not in the US.
- High prevalence of lupin allergy among patients with peanut allergy: Identification of γ-conglutin as major allergen — Annals of Allergy, Asthma & Immunology
- The health benefits of lupin — the powerhouse legume — Healthy Food