Efficacy of Fig (Ficus carica L.) Leaf Tea in Adults with Seasonal Allergies:

– A Double-blind, Randomized, Placebo-controlled Pilot Study –

Abstract

Fig leaf tea processed from fig (Ficus carica L.) leaves has type I allergy suppressive effects. The presumed inhibitory mechanism of fig leaf tea, the dissociation of IgE antibodies from inflammatory cells, could be applied in developing new anti-allergic foods. Therefore, this study aimed to explore the efficacy of fig leaf tea on a small scale as a pilot study for a large-scale human intervention study. Participants with cedar pollinosis were divided into fig leaf tea and green tea intake groups (five participants per group), and each tea was consumed for eight weeks. IgE antibody titers and subjective symptoms worsened in both groups with increasing pollen dispersal. However, nasal examinations indicated a trend toward improvement during the study period. The proportion of Th2 cells was significantly lower in the fig leaf tea group. Therefore, fig leaf tea-induced reduction of Th2 cells was linked to the trend of nasal symptom improvement. Future research into the efficacy of fig leaf tea in alleviating hay fever could use water or other non-bioactive substances as a placebo and nasal symptom assessments as the primary outcome.