Associations between physical activity, sleep patterns and diet quality and menstrual health symptoms in midlife: evidence from the 1970 British Cohort Study

BACKGROUND: Menstrual health symptoms, including painful periods, heavy bleeding, and premenstrual syndrome (PMS), are prevalent in midlife women and may be influenced by lifestyle factors. Identifying modifiable health behaviours associated with these symptoms could inform non-pharmacological interventions. This study examined the associations between diet quality, physical activity, and sleep patterns with menstrual health symptoms in midlife women using data from the 1970 British Cohort Study. METHODS: Participants (N = 2,109) were drawn from the age 46 sweep of the 1970 British Cohort Study, a birth cohort of individuals born within a single week. Dietary data was collected using the 24-hour Oxford WebQ questionnaire and a Mediterranean diet score was derived as an indicator of diet quality. Physical activity (total time and moderate-vigorous physical activity) and sleep patterns (duration, efficiency, regularity) were measured via thigh-worn accelerometers for a 7-day wear period. Quartiles were derived for each continuous exposure, with the healthiest quartile as the reference group. Binary menstrual health outcomes (heavy periods, painful periods, PMS) were self-reported. Binomial logistic regression models estimated associations between individual lifestyle factors and each menstrual symptom, adjusting for irregular menstrual bleeding, contraception use, body mass index (BMI), education, endometriosis diagnosis, smoking status and cohabiting status. RESULTS: Approximately half of participants reported experiencing painful periods (44.1%), heavy periods (51.8%) or PMS (49.5%). Participants in the lowest quartile of diet quality had reduced odds of experiencing PMS symptoms (adjusted OR: 0.75, 95% confidence interval (CI): 0.57, 0.98)). There was no significant association between total physical activity and any of the menstrual symptoms in adjusted models, however, those in the lowest quartile of moderate-vigorous physical activity had 1.35 (1.01, 1.80) times higher odds of having painful periods and 1.33 (0.99, 1.79) times higher odds of having heavy periods in adjusted models. There were no associations with PMS and any physical activity variable. Those in the lowest sleep regularity quartile had 1.43 (1.08,1.91) higher odds of experiencing painful periods, 1.34 (1.00,1.79) higher odds of heavy periods and 1.33 (1.01,1.76) higher odds of PMS in adjusted models. Lowest levels of sleep efficiency showed 1.41 (1.07,1.84) higher odds of painful periods in unadjusted models. Sleep duration was not associated with any menstrual health outcomes. CONCLUSIONS: Findings suggest that specific lifestyle behaviours, such as moderate-vigorous physical activity and sleep regularity, are associated with lower risk of painful periods, with further evidence indicating sleep regularity is also associated with heavy periods and PMS. Future research should explore potential causal relationships and intervention strategies to improve menstrual health through lifestyle modifications.