Dietary patterns are associated with premenstrual syndrome: evidence from a case-control study

Objectives: Premenstrual syndrome (PMS) is a common cyclic psychological and somatic disorder which reduces women's quality of life. Evidence regarding the association between dietary patterns (DPs) and PMS is rare. The study aimed to determine the relationship between dietary patterns and PMS. Design: The case-control study was conducted among women with confirmed PMS and healthy individuals recruited from healthcare centres. Setting: Dietary data were collected using a validated semi-quantitative food frequency questionnaire and DPs were derived using principal component analysis. The association between DPs and likelihood of PMS was determined using logistic regression. Participants: In total, 225 women with PMS and 334 healthy participants aged 20-46 years took part in the study. Results: Three major DPs were identified: (i) 'western DP' characterized by high intake of fast foods, soft drink, and processed meats; (ii) 'traditional DP' in which eggs, tomato sauce, fruits, and red meat were highly loaded; and (iii) 'healthy DP' high in dried fruits, condiments and nuts. After taking all possible confounders into account, individuals in the highest tertile of the western DP were more likely to experience PMS (odds ratio (OR) = 1 center dot 49; 95 % CI: 1 center dot 01, 3 center dot 52), P < 0 center dot 001), whilst both healthy and traditional DP was inversely associated with the syndrome (OR = 0 center dot 31; 95 % CI: 0 center dot 17, 0 center dot 72, P = 0 center dot 02; OR = 0 center dot 33; 95 % CI: 0 center dot 14, 0 center dot 77, P = 0 center dot 01, respectively). Conclusion: The western dietary patterns were positively associated with PMS, whilst the healthy and traditional dietary patterns were inversely associated with it. Further longitudinal studies are required to confirm our findings.