Dietary Phytoestrogen Intake and The Risk of Endometriosis in Iranian Women: A Case-Control Study

Objective The aim of this study is to evaluate the relationship between phytoestrogen intake with endometriosis risk. MaterialsAndMethods A case-control study was conducted on 78 women with a laparoscopically confirmed diagnosis of endometriosis and on 78 normal pelvis women (as the control group). Common dietary intake was collected by a validated 147-item semi-quantitative FFQ. Calculation type of phytoestrogen of each dietary item was computed by the database from the USDA. A logistic regression model was used to determine the association between phytoestrogen intake with endometriosis risk. Results Higher intake of total phytoestrogen (P-trend=0.01), total isoflavones (P-trend=0.002), specially formononetin (P-trend=0.04) and glycitein (P-trend=0.04) total lignan (P-trend=0.01), specially secoisolariciresinol (P-trend=0.01) and lariciresinol (P-trend= 0.02) and matairesinol (P-trend=0.003), total coumestrol (third quartile OR: 0.38; %95CI: 0.15-0.96; P-trend=0.15) is related to reduce endometriosis risk. Among food groups, only isoflavin (OR: 0.48; %95CI: 0.44-0.63), lignan (OR: 0.66; %95CI: 0.62-0.94), coumestrol (OR: 0.64; %95CI: 0.51-0.99) and phytoestrogen (OR: 0.46; %95CI: 0.38-0.83) in dairy product and Coumestrol in fruit (OR: 0.69; %95CI: 0.03-0.77) is associated with endometriosis risk. Conclusion Due to the inflammatory nature of endometriosis and the effect of hormones on the progression of the disease, the role of phytoestrogen consumption in the regression of the disease should be more determined.