Relations between dietary soy intake and premenstrual syndrome in young Chinese women

Abstract

Background: The premenstrual syndrome (PMS) is a collection of physical and emotional symptoms that occurs related to women’s menstrual cycle. PMS usually occurs a few days before the onset of menstruation and relieved by the onset of menstruation. There are more than 200 reported symptoms and the most usual symptoms include abdominal bloating, back pain, breast pain, irritability, fatigue, depression and change in eating patterns. However, the cause of PMS is not clear, but a number of factors have been suggested including disturbances in hormones and neurotransmitters, dietary intake and life style. Besides medication to relieve the symptoms, there are alternative prevention methods including diet and lifestyle changes including regular exercise, adequate sleep, and healthy balanced diet. High soy product intake is one of the suggested alternative dietary therapies for PMS by reducing circulating estrogen. Prior studies have indicated that isoflavones can affect estrogen metabolism and influence ovarian cyclicity. Since PMS is common in Hong Kong, it causes significant burden on quality of life in economic and social aspects by affecting social activities, working, or health care use.

Objectives: To investigate the association between dietary soy intake and premenstrual syndrome among young Chinese female

Design: A cross-sectional analytical study

Methods: The research was carried out in a sample of 242 young Chinese women (mean age 20.8±2.59 years) who are students at the University of Hong Kong in April 2012. Face-to-face survey was carried out in campus. Self-administered questionnaire was used to obtain demographic data. A semi-quantitative food frequency questionnaire with 20 food items was used to estimate the habitual dietary soy exposures. Moos Menstrual Distress Questionnaire was used to assess menstrual history and the PMS score. The study protocol received the approval of the Institutional Review Board of The University of Hong Kong/ Hospital Authority Hong Kong West Cluster. (UW 11-485)

Results: 60% of participating women reported to have premenstrual syndrome. The mean score of total MDQ results at menstrual phase, premenstrual phase and postmenstrual phase were 378.5±70.05, 372.9±66.21, and 351.6±36.3 respectively. Soy intake was significantly negative correlated with MDQ scores in premenstrual phase (r=-0.191, p<0.05) and menstrual phase (r=-0.249, p<0.001). The beneficial effect of dietary soy was especially in pain, auto reaction and behavioral change (p<0.05). Adjusted for potential confounders, soy intake was independently associated with reduced PMS (B= -0.496, p<0.001) at premenstrual phase. Only 37% of those women with PMS would take medication or doctor consultation to relieve the symptoms. Over 78% of participating women were willing to try dietary therapy if it was reported to be helpful. Physical symptoms were the most commonly reported.

Conclusions: Soy intake was associated with reduced PMS score, suggesting it may have beneficial effects on preventing or alleviating severity of PMS. Further prospective study and randomized controlled trials will be needed to demonstrate causality and clinical effectiveness.