Dietary inflammatory potential, oxidative balance score, and risk of breast cancer
Category: Lifestyles Behavior, Energy Balance & Chemoprevention
Conference Year: 2019
Purpose: Diet, inflammation and oxidative stress may play important roles in breastcarcinogenesis, but evidence on the association between inflammatory and pro-oxidativepotential of diet and breast cancer (BC) risk is limited.Methods: Energy adjusted-Dietary Inflammatory Index (E-DII)TM and oxidative balance scores(OBS) were calculated for 44,491 Sister Study cohort participants who completed avalidated food frequency questionnaire at enrollment in 2003-2009; all were included inanalyses. Women aged 35 to 74 years in the U.S. and Puerto Rico were eligible if they hada sister who had been diagnosed with BC. High E-DII and low OBS scores represent a morepro-inflammatory and pro-oxidative diet, respectively. Cox proportional hazards modelswere used to estimate multivariable-adjusted hazard ratios (HR) and 95% confidenceintervals (CIs) for BC risk by E-DII and OBS quartiles, after adjusting for potentialconfounders including known risk factors for BC. Results: We identified 1,846 invasive BCs that occurred at least 1 year after enrollment(mean follow-up 8.5 years). Lower OBS was associated with increased BC risk (HRlowest vs.highest quartile: 1.29 [95%CI, 1.11-1.51], Ptrend=0.003), whereas the positive associationwith E-DII only approached statistical significance (HRhighest vs. lowest quartile: 1.12[95%CI, 0.98-1.29], Ptrend=0.1). However, both indices consistently showed strongassociations with triple-negative BC (HR: 1.84 [95%CI, 1.07-3.17], Ptrend=0.03 for OBS and1.88 [95%CI, 1.13-3.13], Ptrend=0.01 for the E-DII). When the two indices were combined, apro-inflammatory/pro-oxidant diet (highest quartile of E-DII and lowest quartile of OBS)was associated with increased BC risk (HR: 1.30 [95%CI, 1.07-1.56], Ptrend=0.007 for allinvasive BC; 2.08 [95%CI, 1.05-4.11], Ptrend=0.01 for triple-negative BC), compared withan anti-inflammatory/anti-oxidant diet (lowest quartile of E-DII and highest quartile ofOBS). These associations were stronger for postmenopausal BC.Conclusions: Poorer diet quality, as measured by oxidative stress and inflammatorypotential, was positively associated with breast cancer, and in particular triple-negativebreast cancer. Findings need to be replicated using biomarkers of oxidative stress andinflammation.
Keywords: Energyadjusted-DietaryInflammatory Index,oxidative balancescore, breastcancer,triple-negativebreast cancer