Cancer
Inflammatory and insulinemic dietary patterns during adolescence and risk of invasive breast cancer among US women Andrea Romanos-Nanclares* Phuong Anh Le Walter C. Willett Bernard Rosner Wendy Y. Chen Michelle D. Holmes Andrea Romanos-Nanclares A. Heather Eliassen
Adolescence is marked by the rapid proliferation of breast tissue and hormonal changes, presenting a susceptible window for breast carcinogenesis. Exposures during this period, including diet, could influence breast cancer risk. Chronic inflammation and hyperinsulinemia are thought to be important underlying mechanisms for several chronic diseases, including breast cancer. This study examines the association between inflammatory and insulinemic dietary patterns during adolescence and invasive breast cancer risk in adulthood. We analyzed data from 47,355 women aged 33-52 years old in the Nurses’ Health Study II (NHSII) who reported their adolescent diet using a food frequency questionnaire in 1998. We calculated the empirical dietary inflammatory pattern (EDIP) and empirical dietary index for hyperinsulinemia (EDIH) scores, which reflect the diet’s potential to modulate circulating inflammatory biomarkers and C-peptide, respectively. Participants were followed from 1998 until the occurrence of breast or other cancer, death, loss to follow-up, or study end in 2019, whichever occurred first. Multivariable Cox Proportional Hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). During 896,647 person-years of follow-up, we documented 1,945 invasive breast cancer cases. We observed no association between EDIP or EDIH and breast cancer risk. The HRs (highest vs. lowest quintile) were 1.10 (95%CI: 0.94, 1.29) for EDIP and 0.95 (95%CI: 0.80, 1.13) for EDIH. Results did not differ by estrogen receptor status, menopausal status, or body mass index at age 18. In conclusion, adolescent dietary patterns with high inflammatory or insulinemic potential were not associated with increased breast cancer risk.