Soy intake and reduced prevalence of skin allergic diseases symptoms

MOLINAS, JORGE; ARDUSSO, LEDIT; TORRENT, CECILIA; DANERI, PAULA; MOLINAS, SARA M.

Bangkok, Thailand

Congreso; XX World Allergy Congress 2007; 2007

World Allergy Organization

Soy intake and reduced prevalence of skin allergic diseases symptoms Molinas Jorge, Ardusso Ledit, Torrent Cecilia, Daneri Paula, Molinas Sara Licenciatura en Nutrición. Facultad de Química. Universidad del Centro Educativo Latinoamericano. Rosario Centro de Inmunología y Alergia. Hospital Provincial del Centenario. Rosario Farmacología. Fac de Cs. Bioquímicas y Farmacéuticas. Universidad Nacional de Rosario. Introduction: Soy is one of the few foods that contain important levels of linoleic acid, an omega-3 polyunsaturated fatty acid (O3FA). It is known that O3FA intake reduces the production of arachidonic acid derivates, which possess chemotactic activity in inflammatory diseases (for example, leukotriene B4) and it increases the levels of eicosapentaenoic acid derivates, which are able to reduce chronic inflammatory response (for example, leukotriene B5). O3FA produces a potent inhibition of TH2 response in vitro. Objective: To evaluate the association between dietary soy intake and the presence of skin allergic symptoms in adults. Materials and Methods: We conducted a cross-sectional study of 765 students that assist to the Centro Educativo Latinoamericano University in Rosario city, randomly chosen, 638 females (83.4%) and 127 males (16.6%), ranging in age from 17 to 65 years old (x = 21.42 ± 4.18). Students answered specific questionnaires about urticaria/angioedema, contact dermatitis, atopic dermatitis and about the frequency of soyfood intake. Statistical analysis was conducted using EPI-INFO. Results: Differences were found when the food intake was classified into two groups: A (never or less than once a month) and B (once or more than once a month, week or day). For soy-based mayonnaises and margarines intake, 48.1% of the subjects were found in group B and the prevalence of skin diseases within this group was significantly lower than in group A; for example atopic dermatitis: B=22.1% vs A=28.7% (OR=0.71; IC:0.51-0.99; p<0.05), contact dermatitis: B=14.3% vs A=22.8% (OR=0.57; IC:0.38-0.85; p<0.05) and food angioedema: B=12.0% vs A=40.0% (OR=0.20; IC:0.03-1.01; p<0.05). For soy hamburgers and soy breadcrumbs intake, 70.0% of the subjects were found in group B and the prevalence of the different skin diseases within this group was significantly lower than in group A; for example eczema of atopic localization:  B=10.2% vs A=15.7% (OR=0.61; IC:0.38-0.99; p<0.05), medical diagnostic eczema: B=15.0% vs A=21.3% (OR=0.65; IC:0.42-0.99; p<0.05), contact dermatitis: B=16.6% vs A=23.4% (OR=0.64; IC:0.43-0.95; p<0.05) and food angioedema: B=13.8% vs A=66.6% (OR=0.08; IC:0.01-0.74; p<0.05). Group B for soy oil ingestion was only 19.5% and in this group the prevalence of angioedema symptoms (1.3%) was lower than in the rest of groups (5.9%) (OR=0.22; IC: 0.04-0.96; p<0.05). The soyfood ingestion was significantly higher in male and men presented significantly less prevalence of all the symptoms studied. This finding motivated us to make sex adjustment of all the previously shown results. After this stratification the statistical significance remained the same. Similar results were obtained when we adjusted for ingestion of histamine-releasing food products, such as, cheese, chocolates and tomatoes, among others. No significantly differences were found between soy intake and urticaria symptoms.     Conclusions: The results obtained in the present study allow us to estimate that the intake of a soy rich food, at least once a month, could protect against skin disorders, such as atopic dermatitis, contact dermatitis and angioedema, independently of sex and of the ingestion of histamine-releasing food products. Further prospective studies will be needed to understand more about this association.