Poster Topical Area: Diet and Cancer
Poster Board Number: 218
Objectives: An updated version of Healthy Eating Index (HEI-2015) was recently released. While previous versions have been shown to be associated with reduced risk of cardiometabolic disease and mortality, few studies have investigated associations for breast cancer risk or compared the different versions of HEI. We aimed to investigate the associations of HEI-2015 and earlier versions of HEI with breast cancer risk.
Methods: We used data from 47,923 Sister Study participants who completed a validated 109-item food frequency questionnaire at enrollment in 2003–2009. Women aged 35 to 74 years in the U.S. and Puerto Rico were eligible if they had a sister who had been diagnosed with breast cancer. HEI-2015, HEI-2010, HEI-2005, and HEI-2000 were calculated based on food group and nutrient intakes estimated using USDA Food and Nutrient Database for Dietary Studies and Food Patterns Equivalents Database. Cox proportional hazards models were used to estimate multivariable-adjusted hazard ratios (HR) and 95% confidence intervals (CI) for breast cancer risk by HEI quartiles, after adjusting for potential confounders including known risk factors for breast cancer.
Results: We identified 1,862 incident invasive breast cancers that occurred at least 1 year after enrollment (mean follow-up 8.5 years). HEI-2015 was inversely associated with invasive breast cancer (HRhighest vs. lowest quartile: 0.89 [95% CI, 0.77-1.03], Ptrend = 0.08). The association was slightly attenuated using HEI-2010 (HRhighest vs. lowest quartile: 0.92 [95% CI, 0.79-1.06], Ptrend = 0.25), whereas associations were stronger for HEI-2005 and HEI-2000 (HRhighest vs. lowest quartile: 0.86 [95% CI, 0.74-0.99], Ptrend = 0.02; 0.80 [95% CI, 0.70-0.92], Ptrend = 0.001, respectively). When stratified by time-varying menopausal status, we observed significant inverse associations for postmenopausal breast cancer for the HEI-2015 (HR: 0.85 [95% CI, 0.73-1.00]), HEI-2010 (HR: 0.85 [95% CI, 0.72-0.99]), HEI-2005 (HR: 0.81 [95% CI, 0.69-0.95]), and HEI-2000 indices (HR: 0.76 [95% CI, 0.66-0.89]). No differential association by estrogen receptor status was found.
Conclusion: Regardless of specific alterations made to the index over time, adherence to general healthy eating guidelines may reduce breast cancer risk.
This work was supported by the Intramural Research Program of the National Institutes of Health, the National Institute of Environmental Health Sciences [Z01-ES044005].
National Institute of Environmental Health Sciences
Research Triangle Park, North Carolina