Goji berries (Lycium barbarum): risk of allergic reactions in individuals with food allergy.

BACKGROUND New foods are frequently introduced in Western diets for their healthy properties; however, they may produce adverse effects. OBJECTIVE After attending a patient who experienced an allergic reaction to Goji berries, we evaluated the allergenic potential of this food in plant food-allergic individuals, a group that is considered to be at high risk of experiencing a reaction. METHODS We recruited 30 additional plant food-allergic individuals in Spain during 3 months in 2010. Four patients reported symptoms on intake, 6 tolerated the berries, and 20 had never tried Goji berries. Patients underwent skin prick tests with Goji berries, as well as with peach peel and plant food panallergens as markers of cross-reactivity between unrelated foods. We carried out in vitro tests in symptomatic patients. RESULTS Skin tests to Goji berries were positive in 24 patients (77%): 5 symptomatic patients and 19 asymptomatic patients. Positivity to Goji berries was associated with positivity to peach peel and to the panallergen nonspecific lipid transfer protein (LTP). Nearly half of the patients reported symptoms (45%), but 89% of the skin test-positive patients had never eaten Goji berries. We detected specific immunoglobulin E to Goji berries in all cases, and several individuals recognized 2 protein bands in the immunoblot. Addition of LTP to sera mostly inhibited immunoglobulin E binding to an LTP-like band, suggesting a role for this panallergen in sensitization to Goji berries. CONCLUSIONS Our results demonstrate the allergenic potential of Goji berries in high-risk individuals, which is probably due to cross-reactivity with LTP from other foods. The risks of Goji berries should be taken into consideration in individuals with food allergy, especially those who are allergic to LTP.