Association between Inflammatory Dietary Pattern and Mammographic Features

Background: The empirical dietary inflammation pattern score (EDIP), which measures the ability of the diet to regulate chronic inflammation, is associated with both higher adiposity and breast cancer (BC) risk. Mammographic density (MD) is an important risk factor for BC. Objective: We examined the associations between EDIP and mammographic features overall and stratified by menopausal status, and assessed the extent to which these associations are mediated by adiposity. Methods: We included 4145 participants without BC in the Nurses’ Health Study (NHS) and NHSII. Cumulative average EDIP was assessed by food frequency questionnaires every 4–6 y. We assessed MD parameters (percent MD, dense area, and nondense area) and V (measure of grayscale variation). MD parameters were square-root transformed. Multivariable-adjusted linear regression models were used to analyze the associations between EDIP score and MD parameters. Baron and Kenny's regression method was used to assess the extent to which the associations of EDIP and mammographic traits were mediated by BMI. Results: In multivariable-adjusted models, EDIP was significantly inversely associated with percent MD [top compared with bottom quartile, β = –0.57; 95% confidence interval (CI): –0.78, –0.36]. Additional adjustment for BMI attenuated the association (β = –0.15; 95% CI: –0.34, 0.03), with 68% (β = 0.68, 20; 95% CI: 0.54, 0.86) mediation via BMI. In addition, EDIP was positively associated with nondense area after adjusting for BMI and other covariates. No associations were observed for dense area and V measure. Results were similar when stratified by menopausal status. Conclusions: EDIP score was inversely associated with percent MD and positively associated with nondense area, and these associations were largely mediated by BMI.