Dietary Fat Intake and Risk of Ovarian Cancer: A Systematic Review and Dose-Response Meta-Analysis of Observational Studies

Observational studies have reported controversial evidence of the association between dietary fat intake and ovarian cancer. This dose-response meta-analysis aimed to clarify quantitatively the association between dietary fat intake and ovarian cancer. The linear and non-linear relationships between fat intake and risk of ovarian cancer were investigated. Heterogeneity, sensitivity analysis, and publication bias were also assessed. Overall, 21 studies involved approximately 900,000 subjects were included. A significant nonlinear association was found between total fat intake with the risk of ovarian cancer, with a relatively steep slope at total fat intake higher than 30g/day (p non-linearity <.01). Moreover, the risk of ovarian cancer was increased in non-linear form for both saturated and monounsaturated fat from 25g/day (p non-linearity <.05). According to the findings from the linear meta-analysis, we observed a 2, 2, 1, and 1% greater risk of ovarian cancer per 10, 0.5, 2.5g/day and 50mg/day increase in total, trans and monounsaturated fat intake as well as cholesterol, respectively. However, this association for monounsaturated fat was marginally significant (p=.052). The findings of this meta-analysis suggest that dietary total, trans, saturated and partially monounsaturated fat as well as cholesterol intake are positively associated with increased risk of ovarian cancer.