Dietary factors and postmenopausal bleeding: A Mendelian randomization investigation.

Understanding modifiable risk factors for postmenopausal bleeding (PMB) is crucial for developing preventive strategies. However, few studies have explored the relationships between dietary factors and PMB. This study employed Mendelian randomization (MR) to investigate the causal relationships between 20 dietary factors (including vegetables, fruits, meats, and beverages) and PMB risk via data from the UK Biobank and FinnGen Biobank. 3 MR analysis methods were utilized: inverse-variance-weighted, weighted median, and MR-Egger. The inverse-variance-weighted analysis identified that poultry intake (odds ratio [OR] = 3.00, P = .0394), nonoily fish intake (OR = 0.372, P = .0145), and coffee intake (OR = 0.508, P < .0001) were associated with PMB. However, the weighted median method only confirmed the association with coffee intake, and the MR-Egger method did not support any associations. The remaining 17 dietary factors showed no significant association with PMB. This study suggests that poultry intake may increase the risk of PMB, whereas nonoily fish and coffee intake may have protective effects. These findings provide new insights into the dietary determinants of PMB, underscoring the need for further research to elucidate the underlying mechanisms and confirm these associations in diverse populations.