Soy and Menstrual Cramps and Pain (Negative effects)

In a study of "Associations of menstrual pain with intakes of soy, fat and dietary fiber in Japanese women" by C Nagata, K Hirokawa, N Shimizu and H Shimizu, Guarantor: C Nagata and Contributors: CN designed and coordinated the study and had overall responsibility for data analysis and writing the paper. KH and NS coordinated for sample collection. HS helped to design the study and undertook data interpretation. A total of 276 Japanese women aged 19–24 years with Intakes of nutrients and foods including soy products, isoflavones, fats and dietary fiber were estimated by a validated semiquantitative food frequency questionnaire. Severity of menstrual pain was assessed by the multidimensional scoring system reported by Andersch and Milson. The result of the finding indicated that Intake of dietary fiber was significantly inversely correlated with the menstrual pain scale (r=-0.12, P=0.04) after controlling for age, smoking status, age at menarche and total energy intake. Neither soy nor fat intake was significantly correlated with menstrual pain after controlling for the covariates. Researchers concluded that
The cross-sectional difference in dietary fiber intake across the level of menstrual pain was small in magnitude but warrants further studies.